ABSORPTION UNIT is an absorption refrigeration

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					ABSORPTION UNIT is an absorption                      supply air to a common space or are drawing air
refrigeration system which has been factory-          from a common plenum or space.
assembled and tested prior to its installation.
                                                      AIR, OUTSIDE is air from outside the building
ACCA is the Air Conditioning Contractors of           intentionally conveyed by openings or ducts to
America.                                              rooms or to conditioning equipment.

ACCA MANUAL J is the Air Conditioning                 AIR POROSITY is a measure of the air-
Contractors of America document entitled              tightness of infiltration barriers in units
“Manual J - Residential Load Calculation, Eighth      of cubic feet per hour per square foot per inch of
Edition” (2003).                                      mercury pressure difference.
                                                      ACM Joint Appendix I - Glossary
ADDITION is any change to a building that             2005 Joint Appendices Page I-2
increases conditioned floor area and conditioned
volume. Addition is also any change that              AIR, RETURN is air from the conditioned area
increases the floor area or volume of an
                                                      that is returned to the conditioning equipment for
unconditioned building of an occupancy group or
type regulated by Part 6. Addition is also any
change that increases the illuminated area of an
outdoor lighting application regulated by Part 6.     AIR, SUPPLY is air being conveyed to a
See Newly Conditioned Space                           conditioned area through ducts or plenums from
                                                      a heat exchanger of a heating, cooling,
AFUE See Annual Fuel Utilization Efficiency           absorption or evaporative cooling system.

AGRICULTURAL BUILDING is a structure                  A I R B R E A K – A physical separation which
designed and constructed to house farm                may be a low inlet into the indirect waste
implements, hay, grain, poultry, livestock or         receptor from the fixture, appliance, or device
other horticultural products. It is not a structure   indirectly connected.
that is a place of human habitation, a place of
employment where agricultural products                AIR CHAMBER – A pressure surge-absorbing
are processed, treated or packaged, or a place        device operating through the compressibility of
used by the public.                                   air.

AIR, COMBUSTION. See COMBUSTION AIR.                  AIRGAP, DRAINAGE – The unobstructed
                                                      vertical distance through the free atmosphere
                                                      between the lowest opening from any pipe,
AIR, CONDITIONED is air which has been
                                                      plumbing fixture, appliance or appurtenance
treated to achieve a desired level of
                                                      conveying waste to the flood level rim of the
temperature, humidity or cleanliness.

AIR, EXHAUST is air being removed from any            AIRGAP, WATER DISTRIBUTION – The
space or piece of equipment and conveyed              unobstructed vertical distance through the free
directly to the atmosphere by means of openings       atmosphere between the lowest opening from
or ducts.                                             any pipe or faucet conveying potable water to
                                                      the flood level rim of any tank, vat or fixture.
AIR-HANDLING UNIT is a blower or fan used
for the purpose of distributing supply air to a       AIRFLOW ACROSS THE EVAPORATOR is the
room, space or area.                                  rate of airflow, usually measured in cfm across a
                                                      heating or cooling coil. The efficiency of air
AIR, MAKEUP is air which is provided to               conditioners and heat pumps is affected by the
replace air being exhausted.                          airflow across the evaporator (or condenser in
                                                      the case of a heat pump).
AIR-MOVING SYSTEM is a system designed to             See Thermostatic Expansion Valves (TXV).
provide heating, cooling or ventilation in which
                                                      AIR-TO-AIR HEAT EXCHANGER is a device
one or more air-handling units are used to
                                                      which will reduce the heat losses or gains which
occur when a building is mechanically ventilated,     APPLIANCE STANDARDS are the Standards
by transferring heat between the conditioned air      contained in the Appliance Efficiency
being exhausted and the unconditioned air being       Regulations.
                                                      AREA DRAIN – A receptor designed to collect
ALTERATION is any change to a building's              surface or storm water from an open area.
water heating system, space conditioning
system, lighting system, or building envelope         AREAL HEAT CAPACITY See Heat Capacity.
that is not an addition.
                                                      ARI is the Air-Conditioning and Refrigeration
ALTERNATIVE CALCULATION METHOD                        Institute.
is the Alternative Calculation Method (ACM)           ASHRAE is the American Society of Heating,
Approval Manual for the 2001 Energy Efficiency        Refrigerating and Air-Conditioning Engineers.
Standards for Nonresidential Buildings, (P400-
01-011) for nonresidential buildings, hotels,         ASPIRATOR – A fitting or device supplied with
and multi-family residential buildings with four or   water or other fluid under positive pressure
more stories and the Alternative Calculation          which passes through an integral orifice or
Method (ACM) Approval Manual for the 2001             constriction, causing a vacuum.
Energy Efficiency Standards for Residential
Buildings, (P400-01-012) for all single family and    ASSEMBLY BUILDING [Not adopted by HCD]
low-rise multi-family residential buildings.          is a building or a portion of a building used, [For
                                                      SFM] or intended to be used for the gathering
ALTERNATIVE CALCULATION METHODS                       together of fifty (50) or more persons for such
(ACMS) are the Commission's Public Domain             purposes as deliberation, education, instruction,
Computer Programs, one of the Commission's            worship, entertainment, amusement, drinking,
Simplified Calculation Methods, or any                dining or awaiting transportation. [for SFM] or
other calculation method approved by the              education; or structure or portion thereof used or
Commission.                                           intended to be used for the showing of motion
                                                      pictures when an admission fee is charged and
ALTERNATIVE COMPONENT PACKAGE is                      when such building or structure is open to the
one of the sets of low-rise residential               public and has a capacity of 10 or more persons.
prescriptive requirements contained in § 151(f).
Each package is a set of measures that achieve        ASTM is the American Society for Testing and
a level of performance, which meets the
standards. These are often referred to as the
prescriptive packages or packages. "Buildings         ATRIUM is a large-volume space created by
that comply with the prescriptive standards shall     openings connecting two or more stories and is
be designed, constructed and equipped to meet
                                                      used for purposes other than an enclosed
all of the requirements of one of the alternative
                                                      stairway, an elevator hoistway, an escalator
packages of components shown in Tables 151-B
                                                      opening, or as a utility shaft for plumbing,
and 151-C for the appropriate climate zone..."
                                                      electrical, air-conditioning or other equipment,
                                                      and is not a mall.
(AFUE) is a measure of the percentage of heat
                                                      ATTIC is an enclosed unconditioned space
from the combustion of gas or oil which is
                                                      directly below the roof and above the ceiling.
transferred to the space being heated during
a year, as determined using the applicable test       AUDITORIUM: See Occupancy Type.
method in the Appliance Efficiency Regulations
or Section 112.                                       AUTO REPAIR: See Occupancy Type.
                                                      AUTOMATIC MULTI-LEVEL DAYLIGHTING
the regulations in Title 20, Section 1601 et seq.     CONTROL is a multi-level lighting control that
of the California Code of Regulations.                automatically reduces lighting in multiple steps
                                                      or continuous dimming in response to available
daylight. This control uses one or more              BOILER, HIGH PRESSURE is a boiler
photocontrols to detect changes in daylight          furnishing steam at pressures in excess of
illumination and then change the electric lighting   fifteen (15) pounds per square inch (103.4 kPa)
level in response to the daylight changes.           or hot water at temperatures in excess of 250°F
                                                     (121°C) or at pressures in excess of 160 pounds
AUTOMATIC TIME SWITCH CONTROL                        per square inch (1102.4 kPa).
DEVICES are devices capable of automatically
turning loads off and on based on time               BOILER ROOM is any room containing a steam
schedules.                                           or hot water boiler.

AZEOTROPE is a refrigerant blend comprising          BREECHING is a metal connector for medium-
multiple components of different volatiles that,     and high-heat appliances.
when used in refrigeration cycles, do not change
volumetric composition or saturation                 BRINE is any liquid used for the transmission of
temperature as they evaporate or condense at
                                                     heat without a change in its state, having no
constant pressure.
                                                     flash point or a flash point above 150°F (66°C),
                                                     as determined by the requirements of the Fire
B A C K F L O W – The flow of water or other         Code. (See U.F.C. Standard 2-2 in Appendix A.)
liquids, mixtures, or substances into the
distributing pipes of a potable supply of water      BTU/H is the listed maximum capacity of any
from any sources other than its intended source.
                                                     appliance, absorption unit or burner expressed
See Back-Siphonage, Back-Pressure Backflow.
                                                     in British thermal units input per hour, unless
                                                     otherwise noted.
arrangement whereby backflow can occur.
                                                     BUILDING CODE [Not adopted by HCD 1 & 2]
BACK-PRESSURE BACKFLOW – Backflow                    is the building code, which is adopted by this
due to an increased pressure above the supply        jurisdiction. [For DSASS, OSHPD 1, 2, 3 & 4,
pressure, which may be due to pumps, boilers,        SFM] For purpose of the California Mechanical
gravity or other sources of pressure.                Code, “Building Code” shall be the most recent
                                                     edition of the California Building Code.
BACKFLOW PREVENTER – A device or                     Exception: [For HCD 1 & 2] Whenever the term
means to prevent backflow into the potable           “Building Code” is used in this code, it shall
water system.                                        mean the California Building Code, Title 24, Part
BACK-SIPHONAGE – The flowing back of
used, contaminated, or polluted water from a         BUILDING DRAIN – That part of the lowest
plumbing fixture or vessel into a water supply       piping of a drainage system which receives the
pipe due to a pressure less than atmospheric in      discharge from soil, waste, and other drainage
such pipe. See Backflow.                             pipes inside the walls of the building and
                                                     conveys it to the building sewer beginning two
BACKWATER VALVE – A device installed in a            (2) feet (610 mm) outside the building wall.
drainage system to prevent reverse flow.
                                                     BUILDING DRAIN (Sanitary) – A building drain
BATHROOM – A room equipped with a shower             which conveys sewage only.
or bathtub.
                                                     BUILDING DRAIN (St o r m ) – A building drain
BATTERY OF FIXTURES – Any group of two               which conveys storm water or other drainage,
(2) or more similar, adjacent fixtures which         but no sewage
discharge into a common horizontal waste or
soil branch.                                         BUILDING ENERGYEFFICIENCY
                                                     STANDARDS are the California Building Energy
BOILER BLOWOFF – An outlet on a boiler to            Efficiency Standards as set forth in the California
permit emptying or discharge of sediment.            Code of Regulations, Title 24, Part 6.
                                                     Also known as the California Energy Code.
BUILDING ENVELOPE is the ensemble of                 CERTIFICATE OF COMPLIANCE (CF-1R) is a
exterior and demising partitions of a building       document with information required by the
that enclose conditioned space.                      Commission that is prepared by the
                                                     Documentation Author that indicates
BUILDING FACADE See Outdoor Lighting                 whether the building includes measures that
                                                     require field verification and diagnostic testing.
Energy Efficiency Standards                          CERTIFICATE OF FIELD VERIFICATION
                                                     AND DIAGNOSTIC TESTING (CF-4R)
BUILDING SEWER – That part of the horizontal         is a document with information required by the
piping of a drainage system which extends from       Commission that is prepared by the HERS Rater
the end of the building drain and which receives     to certify that measures requiring field
the discharge of the building drain and conveys      verification and diagnostic testing comply with
it to a public sewer, private sewer, private         the requirements.
sewage disposal system, or other point of
disposal.                                            CHIMNEY is a vertical shaft enclosing one or
                                                     more flues for conveying flue gases to the
BUILDING SEWER (Combined) – A building               outside atmosphere.
sewer which conveys both sewage and storm
water or other drainage.                             FACTORY-BUILT CHIMNEY is a listed
BUILDING SEWER (Sanitary) – A building
sewer which conveys sewage only.
                                                     MASONRY CHIMNEY is a chimney of solid
BUILDING SEWER (Storm) – A building sewer            masonry units, bricks, stones, listed masonry
which conveys storm water or other drainage,         units or reinforced concrete, lined with suitable
but no sewage.                                       flue liners.

BUILDING SUBDRAIN – That portion of a                METAL CHIMNEY is a chimney constructed of
drainage system which does not drain by gravity      metal with a minimum thickness not less than
into the building sewer.                             0.127 inch (3.23 mm) (No. 10 manufacturer’s
                                                     standard gage) steel sheet.
BUILDING SUPPLY – The pipe carrying potable
water from the water meter or other source of        CHIMNEY CLASSIFICATIONS:
water supply to a building or other point of use
or distribution on the lot. Building supply shall    CHIMNEY, RESIDENTIAL APPLIANCE-TYPE
also mean water service.                             is a factory-built or masonry chimney suitable for
                                                     removing products of combustion from
CALIFORNIA BUILDING CODE [For DSA/SS]                residential-type appliances producing
– The most recent edition of Title 24, Part 2,       combustion gases not in excess of 1000°F
California Code of Regulations.                      (538°C), measured at the appliance flue outlet.
                                                     Factory-built Type HT chimneys have high-
CAPTIVE-KEY OVERRIDE is a type of lighting           temperature thermal shock resistance.
control in which the key that activates the
override cannot be released when the lights are
                                                     CHIMNEY, LOW-HEAT APPLIANCE-TYPE is a
in the on position.
                                                     factory-built, masonry or metal chimney suitable
                                                     for removing the products of combustion from
                                                     fuel-burning low-h e a t appliances producing
factor for the glass portion only of vertical or
                                                     combustion gases not in excess of 1000°F
horizontal fenestration and is measured at least
                                                     (538°C) under normal operating conditions, but
two and one half inches from the frame. Center
                                                     capable of producing combustion gases of
of glass U-factor does not consider the
                                                     1,400°F (760°C) during intermittent forced firing
U-factor of the frame. Center of glass U-factor is
                                                     for periods up to one hour. All temperatures are
not used
                                                     measured at the appliance flue outlet.
CHIMNEY, MEDIUM-HEAT APPLIANCE-TYPE                   ACM Joint Appendix I – Glossary 2005 Joint
is a factory-built, masonry or metal chimney          Appendices Page I-9
suitable for removing the products of combustion
from fuel-burning medium-heat appliances              COEFFICIENT OF PERFORMANCE (COP),
producing combustion gases not in excess of           COOLING, is the ratio of the rate of net heat
2000°F (1093°C), measured at the appliance            removal to the rate of total energy input,
flue outlet.                                          calculated under designated operating
                                                      conditions and expressed in consistent units, as
CHIMNEY, HIGH-HEAT APPLIANCE-TYPE is a                determined using the applicable test method in
factory-built, masonry or metal chimney suitable      the Appliance Efficiency Regulations or Section
for removing the products of combustion from          112.
fuel-burning high-heat appliances producing
combustion gases in excess of 2000°F                  COEFFICIENT OF PERFORMANCE (COP),
(1093°C), measured at the appliance flue outlet.      HEATING, is the ratio of the rate of net heat
                                                      output to the rate of total energy input,
CHIMNEY CONNECTOR is the pipe which                   calculated under designated operating
                                                      conditions and expressed in consistent units, as
connects a fuel-burning appliance to a chimney.
                                                      determined using the applicable test method in
                                                      the Appliance Efficiency Regulations or Section
CLEAR WATER WASTE – Cooling water and                 112.
condensate drainage from refrigeration and air-
conditioning equipment; cooled condensate from        COMBINATION SPACE-HEATING AND
steam heating systems; cooled boiler blowdown         WATER-HEATING APPLIANCE is an appliance
water.                                                that is designed to provide both space heating
                                                      and water heating from a single primary energy
CLIMATE CONTROL SYSTEM See Space                      source.
Conditioning System.
                                                      COMBINATION THERMOSTATIC/PRESSURE
CLIMATE ZONES are the 16 geographic areas             BALANCING VALVE – A mixing valve which
of California for which the Commission has            senses outlet temperature and incoming hot and
established typical weather data, prescriptive        cold water pressure and compensates for
packages and energy budgets. Climate zone             fluctuations in incoming hot and cold water
boundary descriptions are in the document             temperatures and/or pressures to stabilize outlet
"California Climate Zone Descriptions" (July          temperatures.
1995), incorporated herein by reference.
Figure 101-A is an approximate map of the 16          COMBINATION WASTE AND VENT SYSTEM
climate zones                                         – A specially designed system of waste piping
                                                      embodying the horizontal wet venting of one or
CLINIC SINK – A sink designed primarily to            more sinks or floor drains by means of a
receive wastes from bedpans and having a flush        common waste and vent pipe, adequately sized
rim, an integral trap with a visible trap seal, and   to provide free movement of air above the flow
the same flushing and cleansing characteristics       line of the drain.
as a water closet.
                                                      COMBINED BUILDING SEWER – See Building
CLOSED COMBUSTION SOLID FUEL-                         Sewer, (Combined).
BURNING APPLIANCE is a heat- producing
appliance that employs a combustion chamber           COMMISSARIES SERVING MOBILE FOOD
that has no openings other than the flue collar,      PREPARATION UNITS [FOR DHS] – A food
fuel charging door and adjustable openings            establishment in which food, containers,
provided to control the amount of combustion air      equipment or supplies are stored or handled for
that enters the combustion chamber.                   use in vehicles, mobile food preparation units,
                                                      food carts or vending machines.
CLTD is the Cooling Load Temperature
Difference                                            COMBINED HYDRONIC SPACE/WATER
                                                      HEATING SYSTEM is a system which both
CMC is the 2001 California Mechanical Code.           domestic hot water and space heating
is supplied from the same water heating              plane. The conditioned footprint area may be
equipment. Combined hydronic space heating           equal to the first floor area, or it may be greater,
may include both radiant floor systems               if upper floors project over lower floors. One way
and convective or fan coil systems.                  to think of the conditioned footprint area
                                                     is as the area of the largest conditioned floor in
COMBUSTION AIR is the total amount of air            the building plus the conditioned floor area of
provided to the space which contains fuel-           any projections from other stories that extend
burnIng equipment. Includes air for fuel             beyond the outline of that largest floor.
combustion, draft hood dilution and ventilation of
the equipment enclosure.                             CONDITIONED SPACE is an area, room or
                                                     space normally occupied and being heated or
COMPLIANCE APPROACH is any one of the                cooled for human habitation by any equipment.
allowable methods by which the design and
construction of a building may be demonstrated       CONDITIONED VOLUME is the total volume (in
to be in compliance with Part 6. The compliance      cubic feet) of the conditioned space within a
approaches are the performance compliance            building.
approach and the prescriptive compliance
approach. The requirements for each                  CONFINED SPACE is a room or space having a
compliance approach are set forth in Section         volume less than fifty (50) cubic feet (1.42 m 3)
100 (d) 2 of Part 6.                                 per 1000 Btu/h (293 W) of the aggregate input
                                                     rating of all fuel-burning appliances installed in
COMPRESSOR, POSITIVE DISPLACEMENT is                 that space.
a compressor in which increase in pressure is
attained by changing the internal volume of the      CONTAMINATION – An impairment of the
compression chamber.                                 quality of the potable water which creates an
                                                     actual hazard to the public health through
COMPRESSOR REFRIGERANT is a machine,                 poisoning or through the spread of disease by
with or without accessories, for compressing a       sewage, industrial fluids or waste. Also defined
refrigerant vapor.                                   as High Hazard.

CONDENSER is the part of the system                  CONTINUOUS DIMMING is a lighting control
designed to liquefy refrigerant vapor by removal     method that is capable of varying the light
of heat.                                             output of lamps over a continuous range from
                                                     full light output to minimum light output.
                                                     CONTINUOUS VENT – A vertical vent that is a
which condenses part of the water vapor
                                                     continuation of the drain to which it connects
generated by the burning of hydrogen in fuels.
                                                     CONTINUOUS WASTE – A drain connecting
CONDENSING UNIT is a mechanical                      the compartments of a set of fixtures to a trap or
refrigeration system, consisting of one or more      connecting other permitted fixtures to a common
power-driven compressors, condensers, liquid         trap.
receivers if provided, and the regularly furnished
accessories which have been factory assembled        CONTROLLED VENTILATION CRAWL
and tested prior to its installation.                SPACE (CVC) is a crawl space in a residential
                                                     building where the side walls of the crawlspace
CONDITIONED FLOOR AREA (CFA) is the                  are insulated rather than the floor above the
floor area (in square feet) of enclosed              crawlspace. A CVC has automatically controlled
conditioned space on all floors of a building, as    crawl space vents. Credit for a CVC is permitted
measured at the floor level of the exterior          for low-rise residential buildings that use the
surfaces of exterior walls enclosing the             performance approach to compliance.
conditioned space.
                                                     COOL ROOF is a roofing material with high
CONDITIONED FOOTPRINT is a projection of             thermal emittance and high solar reflectance, or
all conditioned space on all floors to a vertical    lower thermal emittance and exceptionally high
solar reflectance as specified in Section 118 (i),    approved device shall constitute the critical
that reduces heat gain through the roof.              level.

COOL ROOF RATING COUNCIL (CRRC) is a                  CROSS - CONNECTION – Any connection or
not-for-profit organization designated by the         arrangement, physical or otherwise, between a
Commission as the Supervisory Entity with             potable water supply system and any plumbing
responsibility to rate and label the reflectance      fixture or any tank, receptor, equipment or
and emittance of roof products.                       device, through which it may be possible for
                                                      non-potable, used, unclean, polluted and
COOLING is air cooling to provide a room or           contaminated water, or other substances, to
space temperature of 68°F (20°C) or above.            enter into any part of such potable water system
                                                      under any condition.
COOLING LOAD is the rate at which heat must
be extracted from a space to maintain a desired       CRRC See Cool Roof Rating Council.
room condition.
                                                      CTI is the Cooling Tower Institute.
DIFFERENCE (CLTD) is an equivalent                    C-VALUE (also known as C-factor) is the time
temperature difference used for calculating the       rate of heat flow through unit area of a body
instantaneous external cooling loads across a         induced by a unit temperature difference
wall or roof. The cooling load is the CLTD x U-       between the body surfaces, in Btu/(hr. x ft.2 x
factor x Area.                                        °F). It is not the same as K-value or K-factor.

COOLING SYSTEM is all of that equipment,              DAMPERS shall be defined as follows:
including associated refrigeration, intended or       Fire Damper is an automatic-closing metal
installed for the purpose of cooling air by           assembly of one or more louvers, blades, slats
mechanical means and discharging such air into        or vanes complying with recognized standards.
any room or space. This definition shall not          Smoke Damper is a damper arranged to seal
include any evaporative cooler.                       off air flow automatically through a part of an air
                                                      duct system so as to restrict the passage of
COOLING UNIT is a self-contained refrigeration        smoke. Volume Damper is any device which
system which has been factory assembled and           when installed will restrict, retard or direct the
tested, installed with or without conditioned air     flow of air in any duct, or the products of
ducts and without connecting any refrigerant-         combustion in any heat-producing equipment, its
containing parts. This definition shall not include   vent connector, vent or chimney therefrom.
a portable cooling unit or an absorption unit.
                                                      DAYLIT AREA is the floor area that is
COP See Coefficient of Performance                    illuminated by daylight through vertical glazing or
                                                      skylights as specified in Section 131(c).
HCD 1/AC] See Section 101.11 (under “HCD              DECORATIVE GAS APPLIANCE is a gas
1/AC”) of this code.                                  appliance that is designed or installed for visual
                                                      effect only, cannot burn solid wood, and
CRITICAL LEVEL – The critical level (C-L or           simulates a fire in a fireplace.
C/L) marking on a backflow prevention device or
vacuum breaker is a point conforming to               DEGREE DAY, HEATING is a unit, based upon
approved standards and established by the             temperature difference and time, used in
testing laboratory (usually stamped on the            estimating fuel consumption and specifying
device by the manufacturer) which determines          nominal annual heating load of a building. For
the minimum elevation above the flood level rim       any one day, when the mean temperature is less
of the fixture or receptor served at which the        than 65°F, there exist as many degree
device may be installed. When a backflow              days as there are Fahrenheit degrees difference
prevention device does not bear a critical level      in temperature between the mean temperature
marking, the bottom of the vacuum breaker,            for the day and 65°F.
combination valve, or the bottom of any such
DEMISING PARTITIONS are barriers that                 DISTRICT HEATING PLANT is a power boiler
separate conditioned space from enclosed              plant designed to distribute hot water or steam
unconditioned space.                                  to users located off the premises.

DEMISING WALL is a wall that is a demising            DOMESTIC SEWAGE – The liquid and water-
partition.                                            borne wastes derived from the ordinary living
                                                      processes, free from industrial wastes, and of
DESIGN CONDITIONS are the parameters and              such character as to permit satisfactory
conditions used to determine the performance          disposal, without special treatment, into the
requirements of space-conditioning systems.           public sewer or by means of a private sewage
Design conditions for determining design              disposal system.
heating and cooling loads are specified in
Section 144 (b) for nonresidential, highrise          DOWNSPOUT – The rain leader from the roof to
residential, and hotel/motel buildings and in         the building storm drain, combined building
Section 150 (h) for low-rise residential buildings.   sewer, or other means of disposal located
                                                      outside of the building. See Conductor and
DESIGN HEAT GAIN RATE is the total                    Leader.
calculated heat gain through the building
envelope under design conditions.                     DRAFT HOOD is a device built into an
                                                      appliance or made a part of the vent connector
                                                      from an appliance, which is designed to:
calculated heat loss through the building
                                                      1. Assure the ready escape of the flue gases in
envelope under design conditions.
                                                      the event of no draft, back draft or stoppage
                                                      beyond the draft hood.
DEVELOPED LENGTH – The length along the
                                                      2. Prevent a back draft from entering the
center line of a pipe and fittings                    appliance.
                                                      3. Neutralize the effect of stack action of the
                                                      chimney or gas vent upon the operation of the
a heater in which all the products of combustion
generated by the gas-burning device are
released into the outside airstream being
heated.                                               DRAIN – Any pipe which carries waste or water-
                                                      borne wastes in a building drainage system.
                                                      DRAINAGE SYSTEM – Includes all the piping
which is constructed and installed so that all air
                                                      within public or private premises, which conveys
for combustion is derived from the outside            sewage or other liquid wastes to a legal point of
atmosphere and all flue gases are discharged to       disposal, but does not include the mains of a
the outside atmosphere.
                                                      public sewer system or a public sewage
                                                      treatment or disposal plant.
enclosed space that is provided with wood             DUCT is any tube or conduit for transmission of
heating, is provided with mechanical heating that     air. This definition shall not include:
has a capacity exceeding 10 Btu/(hr.×ft.²), or is
                                                      1. A vent, a vent connector or a chimney
provided with mechanical cooling that has a
capacity exceeding 5 Btu/(hr.×ft.²), unless
                                                      2. Any tube or conduit wherein the pressure of
the space-conditioning system is designed and         the air exceeds one (1) pound per square inch.
thermostatically controlled to maintain a process     3. The air passages of listed self- contained
environment temperature less than 55°F or to
maintain a process environment temperature
greater than 90°F for the whole space that the
system serves, or unless the space-conditioning       DUCT FURNACE is a warm air furnace normally
system is designed and controlled to be               installed in an air-distribution duct to supply
incapable of operating at temperatures above          warm air for heating . This definition shall apply
55°F or incapable of operating at temperatures        only to a Warm air heating appliance which
below 90°F at design conditions.                      depends for air circulation on a blower not
                                                      furnished as part of the furnace.
DUCT LOSSES is heat transfer into or out of a         EFFICACY, LAMP is the quotient of rated initial
space conditioning system duct through                lamp lumens divided by the rated lamp power
conduction or leakage.                                (watts), without including auxiliaries such as
                                                      ballasts, measured at 25°C according to IESNA
DUCT SEALING is a procedure for installing a          and ANSI Standards.
space conditioning distribution system that
minimizes leakage of air from or to the               EFFICACY, LIGHTING SYSTEM is the quotient
distribution system. Minimum specifications for       of rated initial lamp lumens measured at 25°C
installation procedures, materials, diagnostic        according to IESNA and ANSI Standards, times
testing and field verification are contained          the ballast factor, divided by the input power
in the Residential and Nonresidential ACM             (watts) to the ballast or other auxiliary device
Approval Manuals.                                     (e.g. transformer); expressed in lumens per
DUCT SYSTEM includes all ducts, duct fittings,
plenums and fans assembled to form a                  ELECTRIC HEATING APPLIANCE is a device
continuous passageway for the distribution of         which produces heat energy to create a warm
air.                                                  environment by the application of electric power
                                                      to resistance elements, refrigerant compressors
DWELLING UNIT [Not adopted by HCD] is a               or dissimilar material junctions.
building or portion thereof which contains living
facilities, including provisions for sleeping,        ELECTRICAL CODE [Not adopted by HCD] is
eating, cooking and sanitation, as required by        the National Electrical Code promulgated by the
this code, for not more than one family.              National Fire Protection Association, as adopted
                                                      by this jurisdiction. Exception: [For HCD 1 &
ECONOMIZER, AIR is a ducting arrangement              HCD 2] Whenever the term “Electrical Code” is
and automatic control system that allows a            used in this code, it shall mean the California
cooling supply fan system to supply outside air       Electrical Code, Title 24, Part 3.
to reduce or eliminate the need for mechanical
cooling.                                              ELECTRIC RESISTANCE HEATING is a
                                                      heating system that converts electric energy
ECONOMIZER, WATER is a system by which                directly into heat energy by passing a current
the supply air of a cooling system is cooled          through an electric resistance. Electric
directly or indirectly by evaporation of water, or    resistance heat is inherently less efficient than
other appropriate fluid, in order to reduce or        gas as a heating energy source because it must
eliminate the need for mechanical cooling.            account for losses associated with generation
                                                      from depletable fossil fuels and transmission to
EER See Energy Efficiency Ratio.                      the building site.

EFFECTIVE APERTURE (EA) is the extent that            EMITTANCE, THERMAL is the ratio of the
vertical glazing or skylights are effective for       radiant heat flux emitted by a sample to that
providing daylighting. The effective aperture for     emitted by a blackbody radiator at the same
vertical glazing is specified in Exception 1 to       temperature.
Section 131(c). The effective aperture for
skylights is specified in Section 146 (a) 4 F.        ENERGY BUDGET is the maximum amount of
                                                      Time Dependent Valuation (TDV) energy that a
EFFECTIVE OPENING – The minimum cross-                proposed building, or portion of a building, can
sectional area at the point of water supply           be designed to consume, calculated with the
discharge measured or expressed in terms of:          approved procedures specified in Title 24, Part
(1) diameter of a circle, or                          6. ACM Joint Appendix I - Glossary
(2) if the opening is not circular, or the diameter   2005 Joint Appendices Page I-14
of a circle of equivalent cross-sectional area.
(This is applicable also to airgap.)                  ENERGY EFFICIENCY RATIO (EER) is the
                                                      ratio of net cooling capacity (in Btu/hr.) to total
                                                      rate of electrical energy (in watts), of a cooling
                                                      system under designated operating conditions,
as determined using the applicable test method       FENESTRATION AREA is the area of
in the Appliance Efficiency Regulations              fenestration products (i.e., windows, skylights
or Section 112.                                      and glass doors) in exterior openings, including
                                                     the sash or frame area. The nominal area (from
ENERGY FACTOR (EF) is the ratio of energy            nominal dimensions such as 4040) or rough
output to energy consumption of a water              opening is also acceptable. Where the term
heater, expressed in equivalent units, under         "glazing area" is used in the standards it is the
designated operating conditions over a 24-hour       entire fenestration area, not just the area of
use cycle, as determined using the applicable        glazing, unless stated otherwise.
test method in the Appliance Efficiency              See Fenestration Product, Glazing Area and
Regulations.                                         Shading.

ENFORCING AGENCY [FOR HCD 1 & 2, SFM,                FENESTRATION PRODUCT is any transparent
DSA/SS, OSHPD 1, 2, 3 & 4] is the designated         or translucent material plus any sash, frame,
department or agency as specified in statutes to     mullions and dividers, in the envelope of a
enforce the specific building standards              building, including, but not limited to, windows,
promulgated or adopted by the specified state        sliding glass doors, French doors, skylights,
agency.                                              curtain walls, garden windows, and other doors
                                                     with a glazed area of more than one half of the
EVAPORATIVE COOLER is a device used for              door area.
reducing the sensible heat of air for cooling by
                                                     FENESTRATION SYSTEM is a collection of
the process of evaporation of water into an
                                                     fenestration products included in the design of
airstream .
                                                     a building.
                                                     See Fenestration Product.
that equipment intended or installed for the         FIELD ERECTED COOLING TOWERS are
purpose of environmental cooling by an               cooling towers which are custom designed for a
evaporative cooler from which the conditioned        specific application and which can not be
air is distributed through ducts or plenums to the   delivered to a project site in
conditioned area.                                    the form of factory assembled modules due to
                                                     their size, configuration, or materials of
EVAPORATOR is that part of a refrigeration           construction.
system in which liquid refrigerant is vaporized to   ACM Joint Appendix I - Glossary
produce refrigeration.                               2005 Joint Appendices Page I-16

ENVELOPE See Building Envelope.                      FIELD-FABRICATED FENESTRATION
                                                     PRODUCT OR EXTERIOR DOOR
EXFILTRATION is uncontrolled outward air             is a fenestration product or exterior door whose
leakage from inside a building, including leakage    frame is made at the construction site of
through cracks and interstices, around               standard dimensional lumber or other
windows and doors, and through any other             materials that were not previously cut, or
exterior partition or duct penetration.              otherwise formed with the specific intention of
                                                     being used to fabricate a fenestration
EXPOSED THERMAL MASS is mass that is                 product or exterior door. Field fabricated does
directly exposed (uncovered) to the conditioned      not include sitebuilt fenestration with a label
space of the building. Concrete floors that are      certificate or products required to have
covered by carpet are not considered exposed         temporary or permanent labels.
thermal mass.
                                                     FIRE CODE [Not adopted by HCD] is the fire
FACTORY ASSEMBLED COOLING TOWERS                     code adopted by this jurisdiction.
are cooling towers constructed from factory
assembled modules either shipped to the site in      FIREPLACE STOVE is a chimney- connected,
one piece or put together in the field.              solid-fuel-burning stove (appliance) having part
                                                     of its fire chamber open to the room.
construction complying with the requirements of        room, building, place or portion thereof,
the Building Code for the time period specified.       maintained, used or operated for the purpose of
                                                       storing, preparing, serving, packaging,
FIXTURE BRANCH – A water supply pipe                   transporting, salvaging or otherwise handling
between the fixture supply pipe and the water          food at the retail level.
distributing pipe.
                                                       FOOD PREPARATION EQUIPMENT is cooking
FIXTURE DRAIN – The drain from the trap of a           equipment intended for commercial use,
fixture to the junction of that drain with any other   including coffee machines, espresso coffee
drain pipe.                                            makers, conductive cookers, food warmers
                                                       including heated food servers, fryers, griddles,
FIXTURE SUPPLY – A water supply pipe                   nut warmers, ovens, popcorn makers, steam
connecting the fixture with the fixture branch.        kettles, ranges, and cooking appliances for use
                                                       in commercial kitchens, restaurants, or other
FIXTURE UNIT – A quantity in terms of which            business establishments where food is
the load-producing effects on the plumbing             dispensed.
system of different kinds of plumbing fixtures are
expressed on some arbitrarily chosen scale.            FORCED AIR-TYPE CENTRAL FURNACE is a
                                                       central furnace equipped with a fan or blower
FLOOD LEVEL – See Flooded.                             which provides the primary means for circulation
                                                       of air.
FLOOD LEVEL RIM – The top edge of a
receptor from which water overflows.                   HORIZONTAL-TYPE CENTRAL FURNACE is a
                                                       furnace designed for low headroom installations
FLOOR FURNACE is a completely self-                    with airflow through the appliance in a horizontal
contained furnace suspended from the floor of          path.
the space being heated, taking air for
combustion from outside such space and with            U P F L O W-TYPE CENTRAL FURNACE is a
means for observing flames and lighting the            furnace designed with air flow essentially in a
appliance from such space.                             vertical path, discharging air at or near the top of
                                                       the furnace.
FLUSH TANK – A tank located above or integral
with water closets, urinals, or similar fixtures for   D O W N F L O W-TYPE CENTRAL FURNACE
the purpose of flushing the usable portion of the      is a furnace designed with air flow essentially in
fixture.                                               a vertical path, discharging air at or near the
                                                       bottom of the furnace.
FLUSH VALVE – A valve located at the bottom
of a tank for the purpose of flushing water            ENCLOSED FURNACE is a specific heating or
closets and similar fixtures.                          heating and ventilating furnace incorporating an
                                                       integral total enclosure and using only outside
FLUSHOMETER TANK – A tank integrated
                                                       air for combustion.
within an air accumulator vessel which is
designed to discharge a predetermined quantity
of water to fixtures for flushing purposes.            FRACTIONATION is a change in composition of
                                                       a blend by preferential evaporation of the more
FLUSHOMETER VALVE – A valve which                      volatile component or condensation of the less
discharges a predetermined quantity of water to        volatile component.
fixtures for flushing purposes and is actuated by
direct water pressure.                                 FUSIBLE PLUG is a device arranged to relieve
                                                       pressure by operation of a fusible member at a
FLUX is the rate of the energy flow per unit           predetermined temperature.
                                                       GAP WIDTH is the distance between glazings in
                                                       multi-glazed systems. This is typically measured
from inside surface to inside surface, though         GROUND SOURCE HEAT PUMP is a heat
some manufacturers may report “overall” IG            pump that uses the earth as a source of energy
width, which is measured from outside surface         for heating and a sink for energy when cooling.
to outside surface.                                   Some systems pump water from an aquifer in
                                                      the ground and return the water to the ground
GAS COOLING EQUIPMENT is cooling                      after transferring heat from or to the water. A few
equipment that produces chilled water or cold air     systems use refrigerant directly in a loop of
using natural gas or liquefied petroleum gas as       piping buried in the ground. Those heat pumps
the primary energy source.                            that use either a water loop or pump water from
                                                      an aquifer have efficiency test methods that
GAS HEATING SYSTEM is a natural gas or                are accepted by the Energy Commission. These
liquified petroleum gas heating system.               efficiency values are certified to the Energy
                                                      Commission by the manufacturer and are
GAS INFILLS are air, argon, krypton, CO2, SF6,        expressed in terms of heating Coefficient
or a mixture of these gasses between the panes        of Performance (COP) and cooling Energy
of glass in insulated glass units.                    Efficiency Ratio (EER).

GEOTHERMAL HEAT PUMP See Ground                       HARD COAT is a low emissivity metallic coating
Source Heat Pump.                                     applied to the glass, which will be installed in a
                                                      fenestration product, through a pyrolytic
GLAZING See Fenestration Product.                     process (at or near the melting point of the glass
                                                      so that it bonds with the surface layer of glass).
GLAZING AREA See Fenestration Area.                   Hard coatings are less susceptible to oxidation
                                                      and scratching as compared to soft
GRAVITY HEATING SYSTEM is any heating                 coats. Hard coatings generally do not have as
system consisting of a gravity-type warm air          low emissivity as soft coats.
furnace, together with all air ducts or pipes and
accessory apparatus installed in connection           HEAT CAPACITY (HC) is the amount of heat
therewith.                                            necessary to raise the temperature of all
                                                      the components of a unit area in an assembly by
GRAVITY-TYPE WARM AIR FURNACE is a                    1°F. It is calculated as the sum of the average
warm air furnace depending primarily on               thickness times the density times the specific
                                                      heat for each component, and is expressed in
circulation of air through the furnace by gravity.
                                                      Btu per square foot per °F.
This definition also shall include any furnace
approved with a booster-type fan which does not
                                                      HEAT PUMP is a device that is capable of
materially restrict free circulation of air through
the furnace when the fan is not in operation.         heating by refrigeration, and that
                                                      may include a capability for cooling.
GREASE INTERCEPTOR – An interceptor of at
                                                      HEAT (ENERGY) RECOVERY VENTILATOR is
least 750 gallon (2839 L) capacity to serve one
                                                      a device intended to remove air from buildings,
(1) or more fixtures and which shall be remotely
located.                                              replace it with outside air, and in the process
                                                      transfer heat from the warmer to the colder
GREASE TRAP – A device designed to retain             airstreams.
grease from one (1) to a maximum of four (4)
fixtures.                                             HEATED SLAB FLOOR is a concrete slab floor
                                                      or a lightweight concrete topping slab laid over a
GREENHOUSE WINDOW is a type of                        raised floor, with embedded space heating hot
fenestration product which adds conditioned           water pipes. The heating system using the
volume but no conditioned floor area to a             heated slab is sometimes referred to as radiant
building.                                             slab floors or radiant heating.

GRILLES See Dividers.                                 HEATING DEGREE DAY is a unit, based upon
                                                      temperature difference and time, used in
                                                      estimating fuel consumption and specifying
nominal annual heating load of a building. For        (including heat pump cooling equipment) with
any one day when the mean temperature is less         less than 65,000 Btu/h output capacity is rated
than 65°F (18°C), there exist as many degree          by the Seasonal Energy Efficiency Ratio (SEER)
days as there are Fahrenheit degrees difference       (equipment of this size may also be rated by the
in temperature between meantemperature for            EER). Electric cooling equipment (including heat
the day and 65°F (18°C).                              pump cooling equipment) with an output
                                                      capacity of 65,000 Btu/h or more is rated by the
HEATING EQUIPMENT includes all warm air               Energy Efficiency Ratio (EER).
furnaces, warm air heaters, combustion
products vents, heating air-distribution ducts and    HERS PROVIDER see Home Energy Rating
fans, all steam and hot water piping, together        System Provider.
with all control devices and accessories installed
as part of, or in connection with, any                HERS RATER See Home Energy Rating
environmental heating system or appliance             System Rater.
regulated by this code.
                                                      HIGH-RISE RESIDENTIAL BUILDING is a
HEATING SEASONAL PERFORMANCE                          building, other than a hotel/motel, of Occupancy
FACTOR (HSPF)                                         Group R, Division 1 with four or more habitable
is the total heating output of a central air-
conditioning heat pump during its normal usage
                                                      HOME ENERGY RATING SYSTEM
period for heating, divided by the total electrical
                                                      PROVIDER is an organization that the
energy input in watt-hours during the same
                                                      Commission has approved to administer a home
period, as determined using the applicable test
                                                      energy rating system program, certify raters
method the Appliance Efficiency Regulations.
ACM Joint Appendix I - Glossary                       and maintain quality control over field verification
2005 Joint Appendices Page I-19                       and diagnostic testing required for compliance
                                                      with the Energy Efficiency Standards.
HEATING SYSTEM is a warm air heating plant            HOME ENERGY RATING SYSTEM RATER is a
consisting of a heat exchanger enclosed in a          person certified by a Commission approved
casing, from which the heated air is distributed      HERS Provider to perform the field verification
through ducts to various rooms and areas. A           and diagnostic testing required for
heating system includes the outside air, return a     demonstrating compliance with the Energy
i r and supply air system and all accessory           Efficiency Standards.
apparatus and equipment installed in connection

                                                      HOOD is an air intake device connected to a
CONDITIONING (HVAC) SYSTEM                            mechanical exhaust system for collecting
is the mechanical heating, ventilating and air        vapors, fumes, smoke, dust, steam, heat or
conditioning system of the building, also known       odors from, at or near the equipment, place or
as the HVAC system. The standards use various         area where generated, produced or released.
measures of equipment efficiency defined
according to the type of equipment installed.         HVAC SYSTEM See HVAC, See Space
Gas (fossil fuel) heating equipment is rated by       Conditioning System.
the Annual Fuel Utilization Efficiency (AFUE).
The heating efficiency of electric heat pumps         HYDRONIC COOLING SYSTEM is any cooling
with less than 65,000 Btu/h cooling capacity is       system which uses water or a water solution as
rated by the Heating Seasonal Performance             a source of cooling or heat rejection, including
Factor (HSPF). The heating efficiency of heat         chilled water systems (both air and water-
pumps with cooling capacity of 65,000 Btu/h or        cooled) as well as water-cooled or evaporatively
more is rated by the Coefficient of Performance       cooled direct expansion systems, such as water
(COP). Electric resistance heating is rated by        source (water-to-air) heat pumps.
HSPF or COP. All electric cooling equipment
HYDRONIC SPACE HEATING SYSTEM is a                    INSULATION Insulation is a material that limits
system that uses water-heating equipment, such        heat transfer. Insulating material of the types
as a storage tank water heater or a boiler, to        and forms listed in Section 118(a) of the
provide space heating. Hydronic space heating         Standards, may be installed only if the
systems include both radiant floor systems and        manufacturer has certified that the insulation
convective or fan coil systems.                       complies with the Standards for Insulating
See Combined Hydronic Space/Water Heating             Material, Title 24, Part 12, Chapter 12-
System                                                13 of the California Code of Regulations.
                                                      Insulation must be placed within or contiguous
INDIRECTLY CONDITIONED SPACE is                       with a wall, ceiling or floor, or over the surface of
enclosed space, including, but not limited to,        any appliance or its intake or outtake
unconditioned volume in atria, that (1) is not        mechanism for the purpose of reducing heat
directly conditioned space; and (2) either (a) has    transfer or reducing adverse temperature
a thermal transmittance area product (UA) to          fluctuations of the building, room or appliance.
directly conditioned space exceeding that to the      Insulation may be installed in wall, ceiling/roof
outdoors or to unconditioned space and does           and raised floor assemblies and at the edge of a
not have fixed vents or openings to the outdoors      slab-on-grade. Movable insulation is designed to
or to unconditioned space, or (b) is a space          cover windows and other glazed openings part
through which air from directly conditioned           of the time to reduce heat loss and heat gain.
spaces is transferred at a rate exceeding three
air changes per hour.                                 INTEGRATED PART LOAD VALUE (IPLV) is a
                                                      single number figure of merit based on part load
INDIRECT WASTE PIPE – A pipe that does not            EER or COP expressing part load efficiency for
connect directly with the drainage system but         air-conditioning and heat pump equipment on
conveys liquid wastes by discharging into a           the basis of weighted operation at various load
plumbing fixture, interceptor, or receptacle which    capacities for the equipment as determined
is directly connected to the drainage system.         using the applicable test method in the
                                                      Appliance Efficiency Regulations or Section 112.
INDUSTRIAL HEATING EQUIPMENT includes                 ACM Joint Appendix I – Glossary 2005 Joint
appliances, devices or equipment used, or             Appendices Page I-22
intended to be used, in an industrial,
manufacturing or commercial occupancy for             ISOLATION DEVICE is a device that prevents
applying heat to any material being processed,        the conditioning of a zone or group of
but shall not include water heaters, boilers, or      zones in a building while other zones of the
portable equipment used by artisans in pursuit of     building are being conditioned.
a trade.
                                                      INVERT – The lowest portion of the inside of a
INFILTRATION CONTROLS are measures                    horizontal pipe.
taken to control the infiltration of air. Mandatory
                                                      LAVATORY [For HCD 1, HCD 2 & DSA/AC] – A
Infiltration control measures include
                                                      plumbing fixture used for washing the hands,
weatherstripping, caulking, and sealing in and
                                                      arms, face and head.
around all exterior joints and openings.
                                                      LAVATORIES IN SETS – Two (2) or three (3)
                                                      lavatories that are served by one (1) trap.
document with information required by the
Commission that is prepared by the builder or
                                                      LEADER – An exterior vertical drainage pipe for
installer verifying that the measure was installed
to meet the requirements of the standards.            conveying storm water from roof or gutter drains.
                                                      See Downspout.
INSULATING GLASS UNIT is a self-contained
                                                      LIQUID LINE is the refrigerant line that leads
unit, including the glazings, spacer(s), films
                                                      from the condenser to the evaporator in a split
(if any), gas infills, and edge caulking, that is
                                                      system air conditioner or heat pump. The
installed in fenestration products. It does not
include the frame.                                    refrigerant in this line is in a liquid state and is at
                                                      an elevated temperature. This line should not be
                                                          designed to distribute the light, to position and
LOW-E COATING is a low emissivity metallic                protect the lamp, and to connect the lamp to the
coating applied to glazing in                             power supply; commonly referred to as "lighting
fenestration products.                                    fixtures" or "instruments."
See Soft Coat and Hard Coat.
                                                          MACERATING TOILET SYSTEM – A system
LIQUID LINE is the refrigerant line that leads            comprised of a sump with macerating pump and
from the condenser to the evaporator in a split           with connections for a water closet and other
system air conditioner or heat pump. The                  plumbing fixtures, which is designed to accept,
refrigerant in this line is in a liquid state and is at   grind and pump wastes to an approved point of
an elevated temperature. This line should not be          discharge.
                                                          MAIN – The principal artery of any system of
LOW-E COATING is a low emissivity metallic                continuous piping to which branches may be
coating applied to glazing in fenestration                connected.
See Soft Coat and Hard Coat.                              MAIN SEWER – See Public Sewer.

LOW PRESSURE HOT WATER-HEATING                            MAIN VENT – The principal artery of the venting
BOILER is a boiler furnishing hot water at                system to which vent branches may be
pressures not exceeding 160 pounds per square             connected.
inch (1102.4 kPa) and at temperatures not
exceeding 250°F (121°C).                                  MANDATORY MEASURES CHECKLIST
                                                          (MF-1R) is a form used by the building plan
LOW PRESSURE STEAM-HEATING BOILER                         checker and field inspector
is a boiler furnishing steam at pressures not             to verify compliance of the building with the
                                                          prescribed list of mandatory features, equipment
exceeding fifteen (15) pounds per square inch
                                                          efficiencies and product certification
(103.4 kPa).
                                                          requirements. The documentation author
                                                          indicates compliance by initialing, checking, or
LOW-RISE RESIDENTIAL BUILDING is a                        marking N/A (for features
building, other than a hotel/motel that is of             not applicable) in the boxes or spaces provided
Occupancy Group R, Division 1, and is three               for the designer.
stories or less, or that is of Occupancy Group R,
Division 3.                                               MECHANICAL COOLING is lowering the
                                                          temperature within a space using refrigerant
LOW SIDE refers to the parts of a refrigeration           compressors or absorbers, desiccant
system subjected to approximate evaporator                dehumidifiers, or other systems that require
pressure.                                                 energy from depletable sources to directly
                                                          condition the space. In nonresidential, high-rise
                                                          residential, and hotel/motel buildings cooling of a
LOW-SLOPED ROOF is a roof that has a ratio                space by direct or indirect evaporation of water
of rise to run of 2:12 or less.                           alone is not considered mechanical cooling.
LPG is Liquefied Petroleum Gas. Propane is one
type of LPG.                                              MECHANICAL HEATING is raising the
                                                          temperature within a space using electric
LUMENS/WATT is the amount of light available              resistance heaters, fossil fuel burners, heat
from a given light source (lumens) divided by the         pumps, or other systems that require energy
power requirement for that light source                   from depletable sources to directly condition the
(watts). The more usable light that a light source        space.
provides per watt, the greater its efficacy.
See Efficacy.                                             MOBILE HOME PARK SEWER – That part of
                                                          the horizontal piping of a drainage system which
LUMINAIRE is a complete lighting unit                     begins two (2) feet (610 mm) downstream from
consisting of a lamp and the parts                        the last mobile home site and conveys it to a
public sewer, private sewer, private sewage         Occupancy
disposal system, or other point of disposal         NOTE: Requirements for high-rise residential
                                                    buildings and hotels/motels are included in the
MOTION SENSOR, LIGHTING is a device that            nonresidential sections of Title 24, Part 6.
automatically turns lights off soon after an area
is vacated. The term Motion Sensor applies to a     NONRESIDENTIAL MANUAL is the manual
device that controls outdoor lighting systems.      developed by the Commission, under Section
When the device is used to control indoor           25402.1(e) of the Public Resources Code, to aid
lighting systems, it is termed an occupant          designers, builders and contractors in meeting
sensor. The device also may be called an            the energy efficiency requirements for
occupancy sensor, or occupant sensing device.       nonresidential, high-rise residential, and
                                                    hotel/motel buildings.
MULLION is a vertical framing member
separating adjoining window or door sections.       OCCUPANCY TYPE is one of the following:
See Dividers                                        Auditorium is the part of a public building where
                                                    an audience sits in fixed seating, or a room,
MULTI-FAMILY DWELLING UNIT is a dwelling            area, or building with fixed seats used for public
unit of occupancy type R, as defined by the         meetings or gatherings not specifically for the
CBC, sharing a common wall and/or ceiling/floor     viewing of dramatic performances.
with at least one other dwelling unit.              Auto repair is the portion of a building used to
ACM Joint Appendix I - Glossary                     repair automotive equipment and/or vehicles,
2005 Joint Appendices Page I-25                     exchange parts, and may include work using an
                                                    open flame or welding equipment.
MULTI-LEVEL LIGHTING CONTROL is a                   Civic meeting space is a city council or board of
lighting control that reduces lighting power in     supervisors meeting chamber, courtroom, or
multiple steps while maintaining a reasonably       other official meeting space accessible to the
uniform level of illuminance throughout the area    public .
controlled.                                         Classroom, lecture, or training is a room or
                                                    area where an audience or class receives
MULTISCENE DIMMING SYSTEM is a lighting             instruction.
control device that has the capability of setting   Commercial and industrial storage is a room,
light levels throughout a continuous range, and     area, or building used for storing items.
that has preestablished settings within the         Convention, conference, multipurpose and
range. NFRC is the National Fenestration Rating     meeting centers are assembly rooms, areas, or
Council. This is a national organization of         buildings used for meetings, conventions and
fenestration product manufacturers, glazing         multiple purposes, including but not limited to,
manufacturers, manufacturers of related             dramatic performances, and that has neither
materials, utilities, state energy offices,         fixed seating nor fixed staging.
laboratories, home builders, specifiers             Corridor is a passageway or route into which
(architects), and public interest groups.           compartments or rooms open.
This organization is designated by the              Dining is a room or rooms in a restaurant or
Commission as the Supervisory Entity, which is      hotel/motel (other than guest rooms) where
responsible for rating the U-factors and solar      meals that are served to the customers will be
heat gain coefficients of manufactured              consumed.
fenestration products (i.e., windows, skylights,    ACM Joint Appendix I - Glossary
glazed doors) that must be used in compliance       2005 Joint Appendices Page I-27
calculations.                                       Dormitory is a building consisting of multiple
See also Fenestration Area and Fenestration         sleeping quarters and having interior common
Product.                                            areas such as dining rooms, reading rooms,
                                                    exercise rooms, toilet rooms, study rooms,
NONCARRIAGE TOILET FACILITY [For                    hallways, lobbies, corridors, and stairwells, other
DSA/SS] – A toilet facility not connected to a      than high-rise residential, low-rise residential,
sewer.                                              and hotel/motel occupancies.
                                                    Electrical/mechanical room is a room in which
NONRESIDENTIAL BUILDING is any building             the building’s electrical switchbox or control
which is a Group A, B, E, F, H, M, or S
panels, and/or HVAC controls or equipment is        being sound in body or mind through medical,
located.                                            dental, or psychological examination and
Exercise center/gymnasium is a room or              treatment, including, but not limited to,
building equipped for gymnastics, exercise          laboratories and treatment facilities.
equipment, or indoor athletic activities.           Museum is a space in which works of artistic,
Exhibit is a room or area that is used for          historical, or scientific value are cared for and
exhibitions that has neither fixed seating nor      exhibited.
fixed staging.                                      Office is a room, area, or building of CBC Group
Financial transaction is a public establishment     B Occupancy other than restaurants.
used for conducting financial transactions          Parking garage is a covered building or
including the custody, loan, exchange, or issue     structure for the purpose of parking vehicles,
of money, for the extension of credit, and for      which consists of at least a roof over the parking
facilitating the transmission of funds              area, often with walls on one or more sides.
General commercial and industrial work is a         Parking garages may have fences or rails in
room, area, or building in which an art, craft,     place of one or more walls. The structure has an
assembly or manufacturing operation is              entrance(s) and exit(s), and includes areas for
performed.                                          vehicle maneuvering to reach the parking
High bay: Luminaires 25 feet or more above the      spaces. If the roof of a parking structure
floor.                                              is also used for parking, the section without an
Low bay: Luminaires less than 25 feet above         overhead roof is considered a parking lot instead
the floor.                                          of a parking garage.
Grocery sales is a room, area, or building that     Precision commercial or industrial work is a
has as its primary purpose the sale of foodstuffs   room, area, or building in which an art, craft,
requiring additional preparation prior to           assembly or a manufacturing operation is
consumption.                                        performed involving visual tasks of small size or
Kitchen/food preparation is a room or area          fine detail such as electronic assembly, fine
with cooking facilities and/or an area where food   woodworking, metal lathe operation, fine hand
is prepared.                                        painting and finishing, egg processing
Laundry is a place where laundering activities      operations, or tasks of similar visual difficulty.
occur.                                              Religious worship is a room, area, or building
Library is a repository for literary materials,     for worship.
such as books, periodicals, newspapers,             Restaurant is a room, area, or building that is a
pamphlets and prints, kept for reading or           food establishment as defined in Section 27520
reference.                                          of the Health and Safety Code.
Lobby, Hotel is the contiguous space in a           Restroom is a room or suite of rooms providing
hotel/motel between the main entrance and the       personal facilities such as toilets and
front desk, including reception, waiting and        washbasins.
seating areas.                                      Retail merchandise sales is a room, area, or
Lobby, Main entry is the contiguous space in        building in which the primary activity is the sale
buildings other than hotel/motel that is directly   of merchandise.
located by the main entrance of the building        School is a building or group of buildings that is
through which persons must pass, including          predominately classrooms and that is used by
reception, waiting and seating areas.               an organization that provides instruction to
Locker/dressing room is a room or area for          students.
changing clothing, sometimes equipped with          Senior housing is housing other than
lockers.                                            Occupancy Group I that is specifically for
Lounge/recreation is a room used for leisure        habitation by seniors, including but not limited to
activities which may be associated with a           independent living quarters, and assisted living
restaurant or bar.                                  quarters. Commons areas may include dining,
Mall is a roofed or covered common pedestrian       reading, study, library or other community
area within a mall building that serves as access   spaces and/or medical treatment or hospice
for two or more tenants.                            facilities.
Medical and clinical care is a room, area, or       Stairs, active/inactive, is a series of steps
building that does not provide overnight patient    providing passage from one level of a building to
care and that is used to promote the condition of   another.
Support area is a room or area used as a               purposes and not classed as a Group B or E
passageway, utility room, storage space, or            Occupancy.
other type of space associated with or                 Division 3 . A building or portion of a building
secondary to the function of an occupancy that         having an assembly room with an occupant load
is listed in these regulations.                        of less than 300 without a legitimate stage,
Tenant lease space is a portion of a building          including such buildings used for educational
intended for lease for which a specific tenant is      purposes and not classed as a Group B or E
not identified at the time of permit application.      Occupancy.
Theater, motion picture, is an assembly room,          Division 4. Stadiums, reviewing stands and
a hall, or a building with tiers of rising seats or    amusement park structures not included within
steps for the showing of motion pictures.              other Group A Occupancies. Specific and
Theater, performance, is an assembly room, a           general requirements for grandstands, bleachers
hall, or a building with tiers of rising seats or      and reviewing stands are in the Building Code .
steps for the viewing of dramatic performances,        Exception : Amusement buildings, or portions
lectures, musical events and similar live              thereof, which are without walls or a roof and
performances.                                          constructed to prevent the accumulation of
Transportation function is the ticketing area,         smoke in assembly areas.
waiting area, baggage handling areas,
concourse, or other areas not covered by               Group B Occupancies Group B Occupancies
primary functions in Table 146-C in an airport         shall include buildings, structures, or portions
terminal, bus or rail terminal or station, subway      thereof, for office, professional or service-type
or transit station, or marine terminal.                transactions, which are not classified as Group
Vocational room is a room used to provide              H Occupancies. Such occupancies include
training in a special skill to be pursued as a         occupancies for the storage of records and
trade.                                                 accounts and eating and drinking
Waiting area is an area other than a hotel lobby       establishments with an occupant load of less
or main entry lobby normally provided with             than fifty (50).
seating and used for people waiting.
Wholesale showroom is a room where
                                                       Group C Occupancies: [For SFM] 1.
samples of merchandise are displayed.
                                                       Organized Camp is a site with program and
                                                       facilities for the primary purposes of providing an
OCCUPANCY CLASSIFICATION                               outdoor group living experience with social,
                                                       spiritual, educational or recreational objectives
Group A Occupancies Group A Occupancies                for five days or more during one or more
include the use of a building or structure, or a       seasons per year. (see Section 18897 of the
portion thereof, for the gathering together of fifty   Health and Safety Code.)
(50) or more persons for purposes such as civic,
social or religious functions, recreation,             Group E Occupancies
education or instruction, food or drink                Division 1. Any building used for educational
consumption, or awaiting transportation. A room                                  th
                                                       purposes through the 12 grade by fifty (50) or
or space used for assembly purposes by less            more persons for more than twelve (12) hours
than fifty (50) persons and accessory to another       per week or four hours in any one day.
occupancy shall be included as a part of that          Division 2. Any building used for educational
major occupancy. Assembly occupancies shall            purposes through the 12th grade by less than
include the following:                                 fifty (50) persons for more than twelve (12)
Division 1 . A building or portion of a building       hours per week or four hours in any one day.
having an assembly room with an occupant load          Division 3. Any building or portion thereof used
of 1,000 or more and a legitimate stage.               for day-care purposes for more than six persons.
Division 2 . A building or portion of a building
having an assembly room with an occupant               Group F Occupancies Group F Occupancies
load of less than 1,000 and a legitimate stage.
                                                       shall include the use of a building or structure, or
Division 2.1. A building or portion of a building
                                                       a portion thereof, for assembling, disassembling,
having an assembly room with an occupant load          fabricating, finishing, manufacturing, packaging,
of 300 or more without a legitimate stage,
                                                       repair or processing operations that are not
including such buildings used for educational
                                                       classified as Group H Occupancies.
Division 1. Moderate-hazard factory and               laboratories may be classified as Group B,
industrial occupancies shall include factory and      Division 2
industrial uses which are not classified as Group     Occupancies when the quantities of materials
F, Division 2 Occupancies.                            are not in excess of those listed in Tables 3-D
Division 2. Low-hazard factory and industrial         and 3-E, California Building Code. Laboratories
occupancies shall include facilities producing        having quantities of materials in excess of those
noncombustible or non-explosive materials             listed in Table 3-E,California Building Code, and
which, during finishing, packing or processing,       which are located below the fourth story may be
do not involve a significant fire hazard.             classified as a Group H, Division 7 Occupancy .

Group H Occupancies Group H Occupancies               Group I Occupancies
shall include buildings or structures, or portions
thereof, that involve the manufacturing,              Division 1.1. Nurseries for the full-time care of
processing, generation or storage of materials        children under the age of six (each
that constitute a high fire, explosion or health      accommodating more than five children)
hazard. For definitions, identification and control   [For SFM six children].Hospitals, sanitariums,
of hazardous materials and pesticides, and the        nursing homes [ForSFM, OSHPD 1, 2 & 3] and
display of nonflammable solid and                     homes for the aged with non-ambulatory
nonflammable or noncombustible liquid                 patients, protective social-care facilities or
hazardous materials in Group B, F, M or S             homes with nonambulatory guests, and similar
Occupancies, see the Fire Code.                       buildings (each accommodating more than five
Division 1. Occupancies with a quantity of            patients or six patients, as required by the office
material in the building in excess of those listed    of the State Fire Marshal).
in the Building Code, which present a high            Division 1.2. Health care centers for ambulatory
explosion hazard.                                     patients receiving outpatient medical care which
Division 2. Occupancies where combustible             may render the patient incapable of unassisted
dust is manufactured, used or generated in such       self-preservation (each tenant space
a manner that concentrations and conditions           accommodating more than five such patients).
create a fire or explosion potential.                 Division 2. Nursing homes for ambulatory
Occupancies with a quantity of material in the        patients [for SFM] where medical care is
building in excess of those listed in the Building    provided, homes for ambulatory children six
Code, which present a moderate explosion              years of age or over where medical care is
hazard or a hazard from accelerated burning.          provided, or homes with ambulatory guests
Division 3. Occupancies where flammable               where medical care is provided, and similar
solids, other than combustible dust, are              buildings and honor farms and conservation
manufactured, used or generated.                      camps housing inmates who are not restrained
Division 4. Repair garages not classified as          (each accommodating more than five patients or
Group S, Division 3 Occupancies.                      children [for SFM] six patients or children).
Division 5. Aircraft repair hangars and heliports     Division 3. Mental hospitals, mental
not classified as Group S, Division 5                 sanitariums, jails, prisons, reformatories and
Occupancies.                                          buildings where personal liberties of inmates are
Division 6 . Semiconductor fabrication facilities     similarly restrained.
and comparable research and development
areas in which hazardous production materials         Group M Occupancies Group M Occupancies
(HPM) are used and the aggregate quantity of
                                                      shall include buildings, structures, or portions
materials is in excess of those listed in the
                                                      thereof, used for the display and sale of
Building Code.                                        merchandise, and involving stocks of goods,
Division 7. Occupancies having quantities of
                                                      wares or merchandise, incidental to such
materials in excess of those listed in the Building
                                                      purposes and accessible to the public.
Code, which are health hazards.
Division 8. Laboratories and similar areas used
for scientific experimentation or research having     Group R Occupancies
quantities of materials not in excess of those        Division 1. Hotels and apartment houses.
listed in Tables 3-D.1 and 3- E, California           Congregate residences (each accommodating
Building Code, and not otherwise classified as        more than ten (10) persons).
Group B, Division 2 Occupancies. Such                 Division 2. Not used.
Division 2.1. [For SFM] Residentially - based,          Ill.
licensed facilities accommodating more than six         Division 2.3.1. [For SFM] Residentially - based
nonambulatory clients. This division may include        facilities providing hospice care throughout
ambulatory clients. Licensing categories that           accommodating six or less bedridden clients.
may use this classification include, but are not        Licensing categories that may use this
limited to: Adult Residential Facilities,               classification are limited to: Congregate Living
Congregate Living Health Facilities, Residential        Health Facilities for the Terminally Ill and
Care Facilities for the Elderly, Group Homes and        Residential Care Facilities for the Chronically Ill.
Residential Care Facilities for the Chronically Ill.    Division 3 DWELLINGS [F or SFM] Dwellings
Division 2.1.1. [For SFM] Residentially - based,        used for large family day-care homes (as
licensed facilities accommodating six or less           defined in Chapter 2, Section 205) and lodging
nonambulatory clients. This division may include        houses. L i c e n s i n g categories that may use
ambulatory clients. Licensing categories that           this classification include, but are not limited to:
may use this classification include, but are not        Adult Daycare Facilities, Family Day-care
limited to: Adult Residential Facilities,               Homes, Adult Day-support Center, Day-care
Congregate Living Health Facilities, Foster             Center for Mildly Ill Children, Infant Care Center
Family Homes, Intermediate Care Facilities for          and School Age Child Day-care Center.
the Developmentally Disabled Habilitative,              Congregate residences (each accommodating
Intermediate Care Facilities for the                    ten (10) persons or less).
Developmentally Disabled Nursing, nurseries for         Division 6 OCCUPANCIES shall be residential
the full-time care of children under the age of         group care facilities which provide care and/or
six, but not including "infants" as defined in          supervisory services. Restraint shall not be
Section 210; Residential Care Facilities for the        practiced in these facilities. Such residential
Elderly, Small Family Homes and Residential             group care facilities are limited to halfway
Care Facilities for the Chronically Ill.                houses such as community correctional centers,
Division 2.2. [For SFM] Residentially - based,          community correction reentry centers,
licensed facilities accommodating more than six         community treatment programs, work furlough
ambulatory clients. This division may include           programs, and alcoholism or drug abuse
nonambulatory clients and shall not exceed six          recovery or treatment f a c i l i t i e s .
nonambulatory clients. Licensing categories that        Division 6.1 OCCUPANCIES are those Division
may use this classification include, but are            6 Occupancies with more than six
limited to: Adult Residential Facilities,               nonambulatory residents.
Residential Care Facilities for the Elderly, Group      Division 6.2 OCCUPANCIES are those Division
Homes, Community Treatment Facilities and               6 Occupancies with more than six ambulatory
Social Rehabilitation Facilities.                       residents
Division 2.2.1. [For SFM] Residentially -based,         Division 6.1.1 OCCUPANCIES are those
licensed facilities accommodating six or less           Division 6 Occupancies with six or less
ambulatory clients. This division may include a         nonambulatory residents.
maximum of two nonambulatory clients.                   Division 6.2.1 OCCUPANCIES are those
Licensing categories that may use this                  Division 6 Occupancies with six or less
classification include, but are not limited to: Adult   ambulatory residents.
Residential Facilities, Intermediate Care
Facilities for the Developmentally Disabled             Group S Occupancies Group S Occupancies
Habilitative, Intermediate Care Facilities for the      shall include the use of a building or structure, or
Developmentally Disabled Nursing, Nursing               a portion thereof, for storage not classified as a
Homes, Residential Care Facilities for the              hazardous occupancy.
Elderly, Foster Family Homes, Group Homes,              Division 1. Moderate-hazard storage
Small Family Homes, Community Treatment                 occupancies shall include buildings or portions
Facilities and Social Rehabilitation Facilities.        of buildings used for storage of combustible
Division 2.3. [For SFM] Residentially - based,          materials that are not classified as Group S,
licensed facilities providing hospice care              Division 2 or Group H Occupancies.
throughout accommodating more than six                  Division 2. Low-hazard storage occupancies
bedridden clients. Licensing categories that may        shall include buildings, structures, or portions
use this classification are limited to: Congregate      thereof, used for storage of noncombustible
Living Health Facilities for the Terminally Ill and     materials such as products on wood pallets or in
Residential Care Facilities for the Chronically         paper cartons with or without single-thickness
divisions, or in paper wrappings, and shall           Building entrance is any operable doorway in
include ice plants, power plants and pumping          or out of a building, including overhead doors.
plants.                                               Building façade is the exterior surfaces of a
Division 3. Division 3 Occupancies shall include      building, not including horizontal roofing, signs,
repair garages where work is limited to               and surfaces not visible from any reasonable
exchange of parts and maintenance requiring no        viewing location.
open flame or welding, motor vehicle fuel-            Canopy is a permanent structure consisting of a
dispensing stations, and parking garages not          roof and supporting building elements, with the
classed as Group S, Division 4 open parking           area beneath at least partially open to the
garages or Group U private garages.                   elements. A canopy may be freestanding or
Division 4. Open parking garages.                     attached to surrounding structures. A canopy
Division 5. Aircraft hangars where work is            roof may serve as the floor of a structure above.
limited to exchange of parts and maintenance          Hardscape is an improvement to a site that is
requiring no open flame or welding, and               paved and has other structural features,
helistops.                                            including but not limited to, curbs, plazas,
                                                      entries, parking lots, site roadways, driveways,
Group U Occupancies                                   walkways, sidewalks, bikeways, water features
Division 1. Private garages, carports, sheds          and pools, storage or service yards, loading
and agricultural buildings.                           docks, amphitheaters, outdoor sales lots, and
Division 2. Fences over six feet (1829 mm)            private monuments and statuary.
high, tanks and towers                                Landscape lighting is lighting that is recessed
                                                      into the ground or paving; mounted on the
OCCUPANT SENSOR, LIGHTING is a device                 ground; mounted less than 42” above grade; or
                                                      mounted onto trees or trellises, and that is
that automatically turns lights off soon after an
area is vacated. The term Occupant Sensor             intended to be aimed only at landscape
applies to a device that controls interior lighting   features.
                                                      Lantern is an ornamental outdoor luminaire that
systems, but can be used interchangeably with
                                                      uses an electric lamp to replicate a pre-electric
occupancy sensor, occupant sensing device,
                                                      lantern, which used a flame to generate light.
and motion sensor.
                                                      Lighting zone is a geographic area designated
                                                      by the California Energy Commission that
OIL INTERCEPTOR – See Interceptor.                    determines requirements for outdoor lighting,
                                                      including lighting power densities and specific
OPERABLE SHADING DEVICE is a device at                control, equipment or performance
the interior or exterior of a building or integral    requirements. Lighting zones are numbered
with a fenestration product, which is capable of      LZ1, LZ2, LZ3, and LZ4. is a permanent lighting
being operated, either manually or automatically,     system consisting of one or more rows of many
to adjust the amount of solar radiation admitted      small lightsattached to a canopy.
to the interior of the building.                      ACM Joint Appendix I - Glossary
                                                      2005 Joint Appendices Page I-31
ORNAMENTAL CHANDELIERS are ceiling-                   Ornamental lighting is post-top luminaires,
mounted, close-to-ceiling, or suspended               lanterns, pendant luminaires, chandeliers, and
decorative luminaires that use glass, crystal,        marquee lighting.
ornamental metals, or other decorative material       Outdoor lighting is all electrical lighting for
and that typically are used in hotel/motels,          parking lots, signs, building entrances, outdoor
restaurants, or churches as a significant element     sales areas, outdoor canopies, landscape
in the interior architecture.                         lighting, lighting for building facades and
                                                      hardscape lighting.
ORNAMENTAL LIGHTING See Outdoor                       Outdoor sales frontage is the portion of the
Lighting                                              perimeter of an outdoor sales area immediately
                                                      adjacent to a street, road, or public sidewalk.
OUTDOOR AIR is air taken from outdoors and            Outdoor sales lot is an uncovered paved area
not previously circulated in the building.            used exclusively for the display of vehicles,
                                                      equipment or other merchandise for sale. All
OUTDOOR LIGHTING definitions include the              internal and adjacent access drives, walkway
following:                                            areas, employee and customer parking
areas, vehicle service or storage areas are not      PHOTOCONTROL is an electric control that
outdoor sales lot areas, but are considered          detects changes in illumination then
hardscape.                                           controls its electric load at predetermined
Parking lot is an uncovered area for the             illumination levels.
purpose of parking vehicles. Parking lot is a type
of hardscape.                                        P I P I N G is the pipe or tube mains for
Paved area is an area that is paved with             interconnecting the various parts of a system.
concrete, asphalt,                                   Piping includes pipe, tube, flanges, bolting,
stone, brick, gravel, or other improved wearing      gaskets, valves, fittings, the pressure-containing
surface, including the curb.                         parts of other components such as expansion
Pendant is a mounting method in which the            joints, strainers and devices which serve such
luminaire is suspended from above.                   purposes as mixing, separating, snubbing,
Post Top Luminaire is an ornamental outdoor          distributing, metering or controlling flow, pipe
luminaire that is mounted directly on top of a       supporting fixtures and structural attachments.
Principal viewing location is anywhere along
                                                     PLENUM is an air compartment or chamber
the adjacent highway, street, road or sidewalk
                                                     including uninhabited crawl spaces, areas above
running parallel to an outdoor sales frontage
                                                     a ceiling or below a floor, including air spaces
Public monuments are statuary, buildings,
                                                     below raised floors of computer/data processing
structures, and/or hardscape on public land.         centers, or attic spaces, to which one or more
Sales canopy is a canopy specifically to cover
                                                     ducts are connected and which forms part of
and protect an outdoor sales area.
                                                     either the supply air, return air or exhaust air
Vehicle service station is a gasoline or diesel
                                                     system, other than the occupied space being
dispensing station.
OUTSIDE AIR See Outdoor Air
                                                     P L U M B I N G – The business, trade, or work
OVERALL HEAT GAIN is the total heat gain             having to do with the installation, removal,
through all portions of the building envelope        alteration, or repair of plumbing systems or parts
calculated as specified in Section 143 (b) 2 for     thereof.
determining compliance with the Overall
Envelope Approach.                                   PLUMBING APPLIANCE – Any one of a special
                                                     class of device or equipment which is intended
OVERALL HEAT LOSS is the total heat loss             to perform a special plumbing function. Its
through all portions of the building envelope        operation and/or control may be dependent
calculated as specified in Section 143 (b) 1 for     upon one or more energized components, such
determining compliance with the Overall              as motors, controls, heating elements, or
Envelope Approach.                                   pressure or temperature-sensing elements.
                                                     Such device or equipment may operate
PACKAGED AIR CONDITIONER OR HEAT                     automatically through one or more of the
PUMP is an air conditioner or heat pump that         following actions: a time cycle, a temperature
combines both the condenser and air handling         range, a pressure
capabilities in a single enclosure or package.       range, a measured volume or weight; or the
                                                     device or equipment may be manually adjusted
PERSONAL SERVICE ROOM [For DSA/SS] –                 or controlled by the user or operator.
A room which is not directly connected with the
production or service function performed by the      PLUMBING APPURTENANCE – A
establishment. Such                                  manufactured device, or a prefabricated
rooms may include, but are not limited to, first     assembly, or an on-the-job assembly
aid or medical rooms, toilet rooms, change           of component parts, and which is an adjunct to
rooms, wash rooms, shower rooms, kitchens            the basic piping system and plumbing fixtures.
and lunch rooms.                                     An appurtenance demands no additional water
                                                     supply, nor does it add any discharge load to a
                                                     fixture or the drainage system. It performs some
PEX. Cross-linked Polyethylene.
                                                     useful function in the operation, maintenance,
servicing, economy, or safety of the plumbing        without the use of ducts and can be readily
system.                                              transported from place to place without
                                                     dismantling any portion thereof.
PLUMBING CODE [Not adopted by HCD] is the
Uniform Plumbing Code promulgated by the             PORTABLE HEATING APPLIANCE is a
International Association of Plumbing and            heating appliance designed for environmental
Mechanical Officials as adopted by this              heating which may have a self-contained fuel
jurisdiction. Exception: [For HCD 1 & 2]             supply and is not secured or attached to a
Whenever the term “Plumbing Code” is used in         building by any means other than by a factory-
this code, it shall mean the California Plumbing     installed power supply cord.
Code, Title 24, Part 6.
                                                     PORTABLE VENTILATING EQUIPMENT is
PLUMBING FIXTURE – An approved type                  ventilating equipment that can be readily
installed receptacle, device, or appliance which     transported from place to place without
is supplied with water or which receives liquid or   dismantling a portion thereof and which is not
liquid-borne wastes and discharges such wastes       connected to a duct.
into the drainage system to which it may be
directly or indirectly connected. Industrial or      POSITIVE DISPLACEMENT COMPRESSOR is
commercial tanks, vats, and similar processing       a compressor in which increase in pressure is
equipment are not plumbing fixtures, but may be      attained by changing the internal volume of the
connected to or discharged into approved traps       compression chamber.
or plumbing fixtures when and as otherwise
provided for elsewhere in this Code.                 POTABLE WATER – Water which is
                                                     satisfactory for drinking, culinary, and domestic
PLUMBING SYSTEM – Includes all potable
                                                     purposes and meets the requirements of the
water building supply and distribution pipes, all
                                                     health authority having jurisdiction.
plumbing fixtures and traps, all drainage and
vent pipe(s), and all building drains and building
sewers, including their respective joints and        POWER BOILER PLANT. One or more power
connection, devices, receptors, and                  steam boilers or power hot water boilers and
appurtenances within the property                    connecting piping and vessels within the same
lines of the premises and shall include potable      premises.
water piping, potable water treating or using
equipment, medical gas and medical vacuum            P R E S S U R E – The normal force exerted by
systems, fuel gas piping, water heaters and          a homogeneous liquid or gas, per unit of area,
vents for same.                                      on the wall of the container.
                                                     (1) Static Pressure – The pressure existing
POLLUTION – An impairment of the quality of          without any flow.
the potable water to a degree which does not         (2) Residual Pressure – The pressure available
create a hazard to the public health but which       at the fixture or water outlet after allowance is
does adversely and unreasonably affect the           made for pressure drop due to friction loss,
aesthetic qualities of such potable waters for       head, meter, and other losses in the system
domestic use. Also defined as Low Hazard.            during maximum demand periods.

PORTABLE COOLING UNIT is a self-contained            PRESSURE BALANCING VALVE – A mixing
refrigerating system, not over three horsepower      valve which senses incoming hot and cold water
rating, which has been factory-assembled and         pressures and compensates for fluctuations in
tested, installed without supply a i r ducts and     either, to stabilize outlet temperature.
without connecting any refrigerant-containing
parts. This definition shall not include an          PRESSURE, DESIGN is the maximum working
absorption unit.                                     pressure for which a specific part of a
                                                     refrigeration system is designed.
evaporative cooler which discharges the              PRIVATE SEWAGE DISPOSAL SYSTEM – A
conditioned air directly into the conditioned area   septic tank with the effluent discharging into a
subsurface disposal field, into one or more           percentage of heat from combustion of gas or oil
seepage pits or into a combination of subsurface      which is transferred to the water. For non-
disposal field and seepage pit or of such other       storage type water heaters, the recovery
facilities as may be permitted under the              efficiency is really a thermal efficiency.
procedures set forth elsewhere in this Code.
                                                      REDUCED FLICKER OPERATION is the
PRIVATE SEWER – A building sewer which                operation of a light, in which the light has a
receives the discharge from more than one (1)         visual flicker less than 30% for frequency and
building drain and conveys it to a public sewer,      modulation.
private sewage disposal system, or other point
of disposal.                                          REFLECTANCE, SOLAR is the ratio of the
                                                      reflected solar flux to the incident solar flux.
PROCESS LOAD is a load resulting from a
process.                                              REFRIGERANT CHARGE is to the amount of
                                                      refrigerant that is installed or “charged” into
PUBLIC SEWER – A common sewer directly                an air conditioner or heat pump. The refrigerant
controlled by public authority.                       is the working fluid. It is compressed and
                                                      becomes a liquid as it enters the condenser. The
RADIANT BARRIER is a highly reflective, low           hot liquid is cooled in the condenser and flows
emitting material installed at the underside          to the evaporator where it released through the
surface of the roof deck and the inside surface       expansion valve. When the pressure is released,
of gable ends or other exterior vertical surfaces     the refrigerant expands into a gas and cools. Air
in attics to reduce solar heat gain into the attic,   is passed over the evaporator to provide the
as specified by Section 151(f)2.                      space cooling. When an air conditioner or heat
                                                      pump has too much refrigerant (overcharged)
RADIANT HEATER is a heater designed to                the compressor may be damaged. When an air
transfer heat primarily by direct radiation           conditioner has too little refrigerant
                                                      (undercharged), the efficiency of the unit is
RAISED FLOOR is a floor (partition) over a            reduced. A thermostatic expansion valve (TXV)
                                                      can mitigate the impact of improper refrigerant
crawl space, or an unconditioned space, or
ambient air.                                          charge. heat primarily by direct radiation.

RECEPTOR – An approved plumbing fixture or            REFRIGERATION MACHINERY ROOM is a
device of such material, shape, and capacity as       space that is designed to safely house
to adequately receive the discharge from indirect     compressors and pressure vessels.
waste pipes, so constructed and located as to
be readily cleaned.                                   REFRIGERATION SYSTEM, ABSORPTION is
                                                      a heat-operated closed-refrigeration cycle in
RECOOL is the cooling of air that has been            which a secondary fluid, the absorbent, absorbs
previously heated by space conditioning               a primary fluid, the refrigerant that has been
equipment or systems serving the same                 vaporized in the evaporator.
                                                      REFRIGERATION SYSTEM, MECHANICAL is
RECOVERED ENERGY is energy used in a                  a combination of interconnected refrigerant
building that (1) is mechanically recovered           containing parts constituting one closed
from space conditioning, service water heating,       refrigerant circuit in which a refrigerant is
lighting, or process equipment after the energy       circulated for the purpose of extracting heat and
has performed its original function; (2) provides     in which a compressor is used for compressing
space conditioning, service water heating, or         the refrigerant vapor.
lighting; and (3) would otherwise be wasted.
                                                      REFRIGERATION SYSTEM, SELF
RECOVERY EFFICIENCY is one measure of                 CONTAINED is a complete factory-assembled
the efficiency of water heaters. It is required       and tested system that is shipped in one or more
for water heating energy calculations for some
                                                      sections and has no refrigerant-containing parts
types of water heaters. It is a measure of the
that are joined in the field by other than           ROOM HEATER is a freestanding,
companion or block valves.                           nonrecessed, environmental heating appliance
                                                     installed in the space being heated and not
REFRIGERATION ROOM or SPACE is a room                connected to ducts.
or space in which an evaporator or brine coil is
located for the purpose of reducing or controlling   ROUGHING - IN – The installation of all parts of
the temperature within the room or space to          the plumbing system which can be completed
below 68°F (20°C).                                   prior to the installation of fixtures. This includes
                                                     drainage, water supply, gas piping, and vent
REGULATING EQUIPMENT – Includes all                  piping and the necessary fixture supports.
valves and controls used in a plumbing system
which are required to be accessible or readily       RUNOUT is piping that is no more than 12 feet
accessible.                                          long and that is connected to a fixture or an
                                                     individual terminal unit.
REHEAT is the heating of air that has been
previously cooled by cooling equipment or            R-VALUE is the measure of the thermal
systems or an economizer.                            resistance of insulation or any material or
                                                     building component expressed in ft²-hr ºF/Btu.
RELATIVE SOLAR HEAT GAIN is the ratio of             See Thermal Resistance
solar heat gain through a fenestration product
(corrected for external shading) to the incident     SAND INTERCEPTOR – See Interceptor.
solar radiation. Solar heat gain includes directly
transmitted solar heat and absorbed solar            SEASONAL ENERGY EFFICIENCY RATIO
radiation, which is then reradiated, conducted,      (SEER) is the total cooling output of a central air
or convected into the space.                         conditioner in Btu during its normal usage period
                                                     for cooling divided by the total electrical energy
RELIEF VENT – A vent, the primary function of        input in watt-hours during the same period, as
which is to provide circulation of air between       determined using the applicable test method in
drainage and vent systems or to act as an            the Appliance Efficiency Regulations.
auxiliary vent on a specially designed system.
                                                     SEEPAGE PIT – A lined excavation in the
RESIDENTIAL BUILDING See High-Rise                   ground which receives the discharge of a septic
Residential Building and Low-Rise Residential        tank so designed as to permit the effluent from
Building.                                            the septic tank to seep through its bottom and
developed by the Commission, under Section           SEPTIC TANK – A watertight receptacle which
25402.1 of the Public Resources Code, to aid         receives the discharge of a drainage system or
designers, builders, and contractors in meeting      part thereof, designed and constructed so as to
energy efficiency standards for low-rise             retain solids, digest organic matter through a
residential buildings.                               period of detention and allow the liquids to
                                                     discharge into the soil outside of the tank
R I S E R – A water supply pipe which extends        through a system of open joint piping or a
vertically one (1) full story or more to convey      seepage pit meeting the requirements of this
water to branches or fixtures.                       Code.

                                                     SERIES FAN-POWERED TERMINAL UNIT is a
RISER HEAT PIPE is a duct which extends at
an angle of more than forty-five (45) degrees        terminal unit that combines a VAV damper in
                                                     series with a downstream fan which runs at all
(0.79 rad) from the horizontal. This definition
                                                     times that the terminal unit is supplying air to the
shall not include any boot connection.
ROOF DR A I N – A drain installed to receive         SERVICE WATER HEATING is heating of water
water collecting on the surface of a roof and to     for sanitary purposes for human occupancy,
discharge it into a leader, downspout, or            other than for comfort heating.
SEWAGE – Any liquid waste containing animal           SMACNA is the Sheet Metal and Air
or vegetable matter in suspension or solution         conditioning Contractors National
and may include liquids containing chemicals in       Association.
                                                      SMOKE DETECTOR is an approved device that
SEWAGE EJECTOR – A device for lifting                 senses visible or invisible particles of
sewage by entraining it in a high-velocity jet of     combustion.
steam, air or water.
                                                      STATE BUILDING CODE [For OSHPD 1, 2, 3 &
SEWAGE PU M P – A permanently installed
                                                      4] is the most recent edition of the California
mechanical device, other than an ejector, for
                                                      Building Code.
removing sewage or liquid waste from a sump

SHADING COEFFICIENT (SC) is the ratio of the          SOIL PIPE – Any pipe which conveys the
solar heat gain through a fenestration product        discharge of water closets, urinals, clinic sinks or
to the solar heat gain through an unshaded 1/8        fixtures having similar functions of collection and
inch thick clear double strength glass under the      removal of domestic sewage, with or without the
same set of conditions. For nonresidential, high-     discharge from other fixtures to the building
rise residential, and hotel/motel buildings,          drain or building sewer.
this shall exclude the effects of mullions, frames,
sashes, and interior and exterior shading             SOLAR HEAT GAIN COEFFICIENT (SHGC) is
devices. See also Solar Heat Gain Coefficient.        the ratio of the solar heat gain entering the
                                                      space through the fenestration area to the
SHIELDED COUPLING – An approved                       incident solar radiation. Solar heat gain includes
elastomeric sealing gasket with an approved           directly transmitted solar heat and absorbed
outer shield and a tightening mechanism.              solar radiation, which is then reradiated,
                                                      conducted, or convected into the space.
SHOCK ARRESTOR – See Water Hammer
Arrestor.                                             SOLAR REFLECTANCE See Reflectance.

SIDE FINS are vertical shading elements               SPACE CONDITIONING SYSTEM is a system
mounted on either side of a glazed opening that       that provides either collectively or individually
can protect the glazing from lateral low              heating, ventilating, or cooling within or
angle sun penetration.                                associated with conditioned spaces in a building.
                                                      The system may operate alone or in conjunction
SITE SOLAR ENERGY is natural daylighting, or          with other systems. See Heating, Ventilating and
thermal, chemical, or electrical energy derived       Air Conditioning.
from direct conversion of incident solar radiation
at the building site.                                 SPECIAL WASTES – Wastes which require
                                                      some special method of handling such as the
SITE-BUILT FENESTRATION is fenestration               use of indirect waste piping and receptors,
designed to be field-glazed or field assembled        corrosion resistant piping, sand, oil or grease
units using specific factory cut or otherwise         interceptors, condensers, or other pretreatment
factory formed framing and glazing units that are     facilities.
manufactured with the intention of being
assembled at the construction site and are            SPECIALTY EVENT CENTERS [For DSA/AC] –
provided with an NFRC label certificate for site-     An open arena used for rallies, concerts,
built fenestration. Examples of site-built            exhibits, etc., with no permanent structure for
fenestration include storefront systems, curtain      purpose of assembly.
walls, and atrium roof systems.
                                                      SPECIFIC HEAT is the quantity of heat that
SINGLE FAMILY DWELLING [Not adopted by                must be added to a unit mass of a
HCD] – A building designed to be used as a            material to increase its temperature by one
home by the owner of such building, which shall       degree. Typical units are Btu/ºF-lb.
be the only dwelling located on a parcel of
ground with the usual accessory buildings.
SPLIT SYSTEM AIR CONDITIONER OR                       sewage or liquid waste and which is located
HEAT PUMP is an air conditioner or heat pump          below the normal grade of the gravity system
that has physically separate condenser and air        and which must be emptied by mechanical
handling units that work together as a single         means.
cooling system.
                                                      SUSPENDED FILMS are low-e coated plastic
STACK VENT – The extension of a soil or waste         films stretched between the elements
stack above the highest horizontal drain              of the spacers between panes of glazing; acts
connected to the stack.                               as a reflector to slow the loss of heat from the
                                                      interior to the exterior.
STANDBY LOSS, BTU/HR is the heat lost per
hour from the stored water above room                 TAILPIECE – The pipe or tubing that connects
temperature. It is one of the measures of             the outlet of a plumbing fixture to a trap.
efficiency of water heaters required for water
heating energy calculations for some                  TDV ENERGY See Time Dependent Valuation
types of water heaters. This standby loss is          (TDV) Energy.
expressed as Btu/hr.
                                                      THERMAL BREAK WINDOW FRAME is metal
STANDBY LOSS, PERCENT is the ratio of heat            fenestration frames that are not solid metal from
lost per hour to the heat content of the stored       the inside to the outside, but are separated in
water above room temperature. It is one of the        the middle by a material, usually urethane, with
measures of efficiency of water heaters required      a lower conductivity.
for water heating energy calculations for some
types of water heaters. Standby loss is               THERMAL CONDUCTIVITY is the quantity of
expressed as a percentage.                            heat that will flow through a unit area of the
                                                      material per hour when the temperature
STEPPED DIMMING is a lighting control method          difference through the material is one degree.
that varies the light output of lamps in one or
more predetermined discrete steps between full        THERMAL EMITTANCE See Emittance.
light output and off.
                                                      THERMAL MASS is solid or liquid material used
STEPPED SWITCHING is a lighting control               to store heat for later heating use or for reducing
method that varies the light output of a              cooling requirements.
lighting system with the intent of maintaining
approximately the relative uniformity of              THERMAL RESISTANCE (R) is the resistance
illumination by turning off alternate groups          of a material or building component to the
of lamps or luminaires.                               passage of heat in (hr. x ft.² x ºF)/Btu.

STORM DRAIN – See Building Drain (Storm).             THERMOSTATIC EXPANSION VALVE
                                                      (TXV) is a refrigerant metering valve, installed in
STORM SE W E R – A sewer used for                     an air conditioner or heat pump, which controls
conveying rainwater, surface water, condensate,       the flow of liquid refrigerant entering the
cooling water, or similar liquid wastes.              evaporator in response to the superheat of the
                                                      gas leaving it.
SUBSOIL DRAIN – A drain which collects
subsurface or seepage water and conveys it to a       THERMOSTATIC VALVE – A mixing valve
place of disposal.                                    which senses outlet temperature and
                                                      compensates for fluctuations in incoming hot or
SUCTION LINE is the refrigerant line that leads       cold water temperatures.
from the evaporator to the condenser in a split
system air conditioner or heat pump. This             TOILET ROOM [For DSA/AC] – A room within
line is insulated since it carries refrigerant at a   or on the premises containing water closets,
low temperature.                                      urinals and other required facilities.

SUMP – An approved tank or pit which receives
THROW DISTANCE is the distance between the           Uniform Mechanical Code published by the
luminaire and the center of the plane lit by the     International Association of Plumbing and
luminaire on a display.                              Mechanical Officials.

TIME DEPENDENT VALUATION (TDV)                       UNCONDITIONED SPACE is enclosed space
ENERGY is the time varying energy caused to          within a building that is not directly conditioned
be used at by the building to provide space          or indirectly conditioned.
conditioning and water heating and for specified
buildings lighting, accounting for the energy        UNCONFINED SPACE is a room or space
used at the building site and consumed in
                                                     having a volume equal to at least fifty (50) cubic
producing and in delivering energy to a site,
                                                     feet (1.42 m3) per 1000 Btu/h (0.293 kW) of the
including, but not limited to, power generation,
                                                     aggregate input rating of all fuel-burning
transmission and distribution losses.
                                                     appliances installed in that space. Rooms
                                                     communicating directly with the space in which
TITLE 24 is all of the building standards and
                                                     the appliances are installed, through openings
associated administrative regulations published
                                                     not furnished with doors, are considered a part
in Title 24 of the California Code of Regulations.
                                                     of the unconfined space.
The Building Energy Efficiency Standards are
contained in Part 6. Part 1 contains the
administrative regulations for the building          UNIT HEATER is a heating appliance designed
standards.                                           for nonresidential space heating and equipped
                                                     with an integral means for circulation of air.
TRAP – A fitting or device so designed and
constructed as to provide, when properly vented,     UNIT INTERIOR MASS CAPACITY (UIMC) is
a liquid seal which will prevent the back passage    the amount of effective heat capacity per unit of
of air without materially affecting the flow of      thermal mass, taking into account the type of
sewage or waste water through it.                    mass material, thickness, specific heat, density
                                                     and surface area. See also Thermal Mass.
TRAP ARM – That portion of a fixture drain
between a trap and the vent.                         UNSANITARY (Insanitary) – See Insanitary.

TRAP PRIMER – A device and system of piping
that maintains a water seal in a remote trap.
                                                     UNUSUALLY TIGHT CONSTRUCTION is
TRAP SEAL – The vertical distance between            construction where:
the crown weir and the top dip of the trap.          1. Walls and ceilings exposed to the outside
                                                     atmosphere have a continuous water vapor
CROWN WEIR (Trap Weir) –the lowest point in          retarder with a rating of one perm or less with
the cross section of the horizontal waterway at      any openings gasketed or sealed;
the exit of the trap.                                2. Weatherstripping is on openable windows and
                                                     doors; and
TOP DIP (of Trap ) – the highest point in the        3. Caulking or sealants are applied to areas
internal cross section of the trap at the lowest     such as joints around window and door frames,
part of the bend (inverted siphon). By contrast,     between sole plates and floors, between wall-
the bottom dip is the lowest point in the internal   ceiling joints, between wall panels and at
cross section.                                       penetrations for plumbing, electrical and gas
                                                     lines and at other openings.
U-FACTOR is the overall coefficient of thermal
transmittance of a construction assembly, in
                                                     U.P.C. [For HCD 1 & HCD 2, DSA/AC, SFM,
Btu/(hr. x ft.² x ºF), including air film
                                                     DHS, DSA/SS, OSHPD 1, 2, 3 & 4] – The latest
resistance at both surfaces.
                                                     edition of the Uniform Plumbing Code, published
                                                     by the International Association of Plumbing and
U-VALUE See U-factor.
                                                     Mechanical Officials.
UMC [For HCD 1 & 2, SFM, DSA/SS, OSHPD 1,
2, 3 & 4] is the most recent edition of the
VACUUM BREAKER – See Backflow                        VENTED APPLIANCE CATEGORIES
Preventer.                                           Category I is an appliance which operates with
                                                     a non-positive vent static pressure and with a
VACUUM RELIEF VA L V E – A device that               vent gas temperature that avoids excessive
prevents excessive vacuum in a pressure              condensate production in the vent.
vessel.                                              Category II is an appliance which operates with
                                                     a non-positive vent static pressure and with a
VAPOR BARRIER is a material that has a               vent gas temperature that may cause excessive
permeance of one perm or less and that               condensate production in the vent.
provides resistance to the transmission of water     Category III is an appliance which operates with
vapor.                                               a positive vent static pressure and with a vent
                                                     gas temperature that avoids excessive
VARIABLE AIR VOLUME (VAV) SYSTEM is a                condensate production in the vent.
space conditioning system that maintains             Category IV is an appliance which operates with
comfort levels by varying the volume of              a positive vent static pressure and with a vent
conditioned air to the zones served.                 gas temperature that may cause excessive
                                                     condensate production in the vent.
VENT – Any pipe provided to ventilate a
plumbing system, to prevent trap siphonage and       VENTED DECORATIVE APPLIANCE is a
back pressure, or to equalize the air pressure       vented appliance whose only function is
within the drainage system.                          providing an esthetic effect of flames.
Type B Gas Vent is a factory-made gas vent
listed by a nationally recognized testing agency     VENTED WALL FURNACE is a vented
for venting listed or approved appliances
                                                     environmental heating appliance designed for
equipped to burn only gas.                           incorporation in, or permanent attachment to, a
Type BW Gas Vent is a factory-made gas vent
                                                     wall, floor, ceiling or partition and arranged to
listed by a nationally recognized testing agency
                                                     furnish heated air by gravity or by a fan. This
for venting listed or approved gas-fired vented
                                                     definition shall not include floor furnaces, unit
wall furnaces.
                                                     heaters and room heaters.
Type L is a venting system consisting of listed
vent piping and fittings for use with oil-burning
appliances listed for use with Type L or with        VENTILATING CEILING is a suspended ceiling
listed gas appliances.                               containing many small apertures through which
                                                     air, at low pressure, is forced downward from an
                                                     overhead plenum dimensioned by the concealed
VENT CONNECTOR, GAS is that portion of a
gas-venting system which connects a listed gas
appliance to a gas vent and is installed within      space between the suspended ceiling and the
the space or area in which the appliance is          floor or roof above.
                                                     VENTILATION AIR is that portion of supply air
VENT PIPE – See Vent.                                which comes from outside plus any
                                                     recirculated air that has been treated to maintain
VENT STACK – The vertical vent pipe installed        the desired quality of air within a designated
primarily for the purpose of providing circulation   space. See also Outside Air.
of air to and from any part of the drainage
system.                                              VENTILATION SYSTEM is all of that equipment
                                                     intended or installed for the purpose of supplying
VENT SYSTEM – A pipe or pipes installed to           air to, or removing air from, any room or space
provide a flow of air to or from a drainage          by mechanical means, other than equipment
system or to provide a circulation of air within     which is a portion of an environmental heating,
such system to protect trap seals from               cooling, absorption or evaporative cooling
siphonage and back- pressure.                        system.

                                                     VENTING SYSTEM is the vent or chimney and
                                                     its connectors, assembled to form a continuous
open passageway from an appliance to the             water supply so as to change its chemical
outside atmosphere for the purpose of removing       content or remove suspended solids by filtration.
products of combustion. This definition also shall
include a venting assembly which is an integral      WATER-DISTRIBUTING PIPE – In a building or
part of an appliance.                                premises, a pipe which conveys potable water
                                                     from the building supply pipe to the plumbing
VENTING SYSTEM—GRAVITY-TYPE is a                     fixtures and other water outlets.
system which depends entirely on the heat from
the fuel being used to provide the energy            WATER HAMMER ARRESTOR – A device to
required to vent an appliance.                       absorb hydraulic shock, either of the air
                                                     chamber or mechanical device design.
system which depends on a mechanical device          WATER HEATER or HOT WATER-HEATING
to provide a positive draft within the venting       BOILER is an appliance designed primarily to
system.                                              supply hot water and is equipped with automatic
                                                     controls limiting water temperature to a
VERTICAL PIPE – Any pipe or fitting which is         maximum of 210°F (99°C).
installed in a vertical position or which makes an
angle of not more than forty-five (45) degrees       WATER MAIN (STREET MAIN) – A water-
with the vertical.                                   supply pipe for public or community use.

VINYL WINDOW FRAME is a fenestration                 WATER SUPPLY SYSTEM – The building
frame constructed with a polyvinyl chloride          supply pipe, the water distributing pipes and the
(PVC) which has a lower conductivity than metal      necessary connecting pipes, fittings, control
and a similar conductivity to wood.                  valves, backflow prevention devices and all
                                                     appurtenances carrying or supplying potable
VISIBLE LIGHT TRANSMITTANCE (VLT) is the             water in or adjacent to the building or premises.
ratio (expressed as a decimal) of visible light
that is transmitted through a glazing material to    WET VENT – A vent which also serves as a
the light that strikes the material.                 drain.

                                                     WHIRLPOOL BA T H T U B – A bathtub fixture
                                                     equipped and fitted with a circulating piping
                                                     system designed to accept, circulate and
                                                     discharge bathtub water upon each use.
closet installed in such a way that no part of the   WINDOW is fenestration that is not a skylight.
water closet touches the floor.
                                                     WINDOW WALL RATIO is the ratio of the
WARM AIR FURNACE is an environmental                 window area to the gross exterior wall area.
heating appliance designed or arranged to
discharge heated air through any duct or ducts.      YOKE VENT – A pipe connecting upward from a
This definition shall not include a unit heater.     soil or waste stack to a vent stack for the
                                                     purpose of preventing pressure changes in the
WASTE PIPE – A pipe which conveys only               stacks.
liquid waste, free of fecal matter.
                                                     ZONAL CONTROL is the practice of dividing a
WATER CLOSET [For HCD 1 & HCD 2,                     residence into separately controlled HVAC
DSA/AC] – A plumbing fixture (which may be           zones. This may be done by installing multiple
used for both defecation or urination) in which      HVAC systems that condition a specific part of
the waste matter is removed by flushing with         the building, or by installing one HVAC system
water.                                               with a specially designed distribution system that
                                                     permits zonal control. The Energy Commission
WATER CONDITIONING OR TREATING                       has approved an alternative calculation method
DEVICE – A device which conditions or treats a       for analyzing the energy impact of zonally
controlled space heating and cooling systems.
To qualify for compliance credit for zonal control,
specific eligibility criteria specified in the
Residential ACM Manual must be met.

group of spaces within a building with sufficiently
similar comfort conditioning requirements so that
comfort conditions, as specified in Section 144
(b) 3 or 150 (h), as applicable, can be
maintained throughout the zone by a single
controlling device for each zone.


California Building Standards Commission, 2001
California Plumbing Code

California Building Standards Commission, 2001
California Mechanical Code

California Energy Commission, 2005 Energy
Efficiency Standards for Residential and
Nonresidential Buildings