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HVAC Basics PPT - HVAC 101

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HVAC Basics PPT - HVAC 101 Powered By Docstoc
					HVAC Basics

The Basics of Heating, Ventilation
      and Air Conditioning
    Presented by: Mark Kartchner, PE, LEED
             Kartchner Engineering
Energy Use – Office Buildings
  Mechanical System Costs
                                     Mechanical System Costs (Provide & Install)

              25
                                                                                                              19             20
              20
Dollars ($)




                                                              14           14.5            14.5
              15                                12
                                  10.5
              10       8

              5

              0
                   RTU-Gas/Air   RTU-Heat   VAV-Elec Heat Multi Zone RTU VAV-Hot Wtr     WSHP-HP,         DOAS w / 4-      Variable
                     Cooled       Pumps                                     Heat       Boiler, Chiller,   Pipe Fan Coil   Refrigerant
                                                                                       Cooling Tow er                      Volume




     First Cost - Water cooled chillers beat Air cooled chillers at
     about 200 Tons (80,000 SF)
     SEL HQ VAV-$10.5/SF, FP-$1.9/SF, Plumb-$3.4/SF 90,000 SF
     CWC $12.5/SF WSHP & $3.5/SF Plumb 90,000 SF
HVAC Rules of Thumb
Air - 1 CFM/SF
Cooling (office) – 300/400 SF/Ton
Cooling (office) 400 CFM/Ton
Heating 25-35 btuh/sf floor area
Outside Air – 20 CFM/person
Toilet/Jan Closet – 10 air changes/hour
HVAC Equipment/SF
Mechanical Room (Boilers/Chillers/Pumps/Misc) =
   GU College Hall = 2000 SF/186,000 = 1.1%


Mechanical Room (Boilers/Pumps/Misc) =
   RTF (tight) – 300 SF/28,000 SF = 1.1%
   Colbert Elementary – 312 SF/ 40,000 SF = 0.8%


RTU (Gas/Electric/VAV) =
   SEL Office (35’x12’ (2))/95,000 SF
Building Envelope
Load Calculations
Heating and Cooling
Accuracy important!
Design conditions
Building shell load
R, U value
Internal load
Ventilation load
Infiltration
Occupancy schedules
Heat Transfer

Conduction
Convection
Radiation
Resistance (R-Value)
                       U-Value is the rate of
U=1/R                  heat flow in Btu/h
                       through a one ft2 area
Q = U x A x T         when one side is 1oF
                       warmer
Actual R-Values
Window Types
Solar Heat Gain Coefficient




                      The amount of solar
                      heat energy allowed to
                      pass through a window

                      Example:  SHGC = 0.40
                      Allows 40% through and
                      turns 60% away
Window Properties




 Energy Calculations in the Spokane region show that
 reflective, and tinted windows increase energy usage on an
 annual basis.
Energy Saving Design Methods

����   Air Side Economizers
����   Water Side Economizers
����   Variable Frequency Drives
����   Building Diversity
����   Part Load Performance
����   Thermal Storage
����   Heat/Energy Recovery
HVAC SYSTEMS
 Heating, Ventilation and Air
 Conditioning
 Provides comfort for people
 Allows humans to exist
 under adverse conditions.
Basic Refrigeration Cycle
System Types
 Packaged Rooftop Unit
 Split System
 Air to Air Heat Pump
 Water Source Heat Pump
 Geothermal
 VAV Variable Air Volume
 Under Floor Air Distribution (UFAD)
 Air to Air
 Hydronic (water)
 PTAC / PTHP
Packaged Rooftop Units (RTU)
Split System
  Heat Pump (Air to Air)
• Operate on simple
  refrigeration cycle
• Reversing the cycle
  provides heating
• Temperature
  limitations
• Air to air
• Water source
• Geothermal
• Lake coupled
Water Source Heat Pump
Geothermal Heat Pump Systems
(VAV) Variable Air Volume
VAV Terminal Units
Variable volume:     Constant volume:
  Parallel             Series
Under Floor Air Distribution (UFAD)

 Advantages
     Individual Controllability
     Re-Configurability
     2 Extra LEED Points
 Disadvantages
     More Expensive ($8/SF
      for raised floor)
     Flexible for Change
     2 Extra LEED Points
 Inland Power &
 Light
     First UFAD in area
Hydronic systems
Four Pipe Fan Coil
VAV w/ HW Reheat
Hydronic System Major Equipment


 Chillers

 Boilers

 Cooling Towers
Chilled Water System
Economizers




   Air Side   Water Side
  Economizers
Free cooling source: When available, use cool
  outdoor air instead of mechanically cooled air.
Minimum supply                                       55 oF and
of outside air                                       up
                       55 oF   85%
                               outside
                               air
                               85%
                  80   oF      exhaust                     80 oF


Normal Operation                 Economizer Operation
Outside air dampers are          Outside air dampers are fully
positioned to provide the        open. Maximum outside air is
minimum outside air              provided

                                                           HVAC-29
Enthalpy Wheels
Air Distribution
  Grilles, Registers
     Many options
     GU Russell Theatre
      Return Grille
  Return Plenum
     Extra cost for plenum
      rated cable is less than
      cost of return ductwork
     No Combustables
Outside Air Louvers
 Outside Air Louvers
 provide an opening in a
 building wall to push air
 out, or pull air in.
 Provide clean outdoor air,
 avoid:
    loading docks
    exhaust vents
    plumbing stacks
    waste collection
    stagnant water
Metal Ducts
 Square Ductwork
    Most common
    Low height
 Round Ductwork
    Less Expensive
    Easy to Install
    Lower static pressure
    Taller than Rectangular
    Higher pressure
    Less Sound
 Oval Ductwork
    Same advantages of round
    Height similar to rectangular
    More expensive than rectangular
Fabric Ducts

 Great for certain
 applications
    Gyms
    Pools
    Manufacturing
    Spokane Science
     Museum
                       Saved $300,000 in
 Advantages            cost at high
    Great Diffusion   school. Lowered
                       chilled water temp,
    Easily Cleaned
                       & air temperatures
    Fun
    Same cost as
     metal
Additional Equipment
Heat Exchangers
Humidifiers
Silencers
Kitchen Hoods
Type 1: Hoods designed for grease exhaust
applications
Type 2: Hoods designed for heat and steam
removal and other non grease applications. (NFPA       A restaurant with a commercial gas range is
                                                       represented by the resteaurant owner to be


96 does not cover)
                                                       used ony for the preparation of soups. What
                                                       type hood is required?
                                                       Type 1 hood is for collection and removal of


Where are Type 1 Commercial Hoods Required?
                                                       grease laden vapors,and smoke. Type II
                                                       hood is for removal of steam, odors, and
                                                       vapors. It would be hard pressed to find a
                                                       restaurant that only produces soups, with
   NFPA 96 “Cooking equipment used in processes       that commercial range. Hoods: where
                                                       required, installed at or above all commercial-

    producing smoke and grease-laden vapors shall be   type deep fat fryers, broilers, fry grills, steam-
                                                       jacketed kettles, hot-top ranges, ovens,

    equipped with…”
                                                       barbeques, rotisseries, dishwashing
                                                       machines, and similar equipment that
                                                       produces comparable amounts of steam,

   NPFA 96-A-1-1 “…intended to include residential    smoke, grease, or heat in a food processing
                                                       establishment. Food processing

    cooking equipment where used for purposes other
                                                       establishment shall include any building or
                                                       portion used for the processing of food. Soup
                                                       is a liquid food made up of simmering

    than residential family use”                       vegetables, seasonings, and often meat or
                                                       fish. It is the potential of the equipment
                                                       (Commercial gas range), rather than the

Type 1 Hood Clearances                                 utilization, that must be evaluated. So, what
                                                       type of hood would be required for that
                                                       commercial gas range in a restaurant would

    18 inches to combustible material
                                                       honestly be open for discussion. You will
                                                      probably have some input from your local
                                                       Fire Dept. through plan check as with the

    3 inches to limited-combustible material
                                                       County Health dept. Requirements. I know of
                                                      one City close to us that when a pizza parlor
                                                       opens, no matter what, they require a type 1

    0 inches to noncombustible material
                                                       hood. Depending on the type of pizza oven,
                                                      we have allowed a type II.
Kitchen Hood Types
Exhaust Hood w/ Supply Air
Supplied by Space
Exhaust Hood w/Supply Air on
Outside of Hood
Exhaust Hood w/Supply Air on
Inside of Hood
Vapor Hoods
   Simple hoods designed to remove
    minimal heat, and high vapor.
Comfort
Comfort is primary
intent of HVAC
systems.
Productivity
Building Durability
Health
Mold
ASHRAE Comfort Zone
Psychrometrics
Dry bulb temp.
Wet bulb temp.
Humidity
Dew point
Moisture content
Heating
Cooling
Humidify
De-Humidify
Historical Minimum Ventilation Rates
(cfm/person)

70
                                                                                                                    Smoking 62-89
60

50

40                                                             Flugge
                                   Billings
                                                               1905
                                   1895
     Nightengale
30                                                                                                           Smoking 62-81
     1865
                                                                                                                                          ASH-
                                                                                                                                          RAE
20                                                                                                      ASHRAE                            62-89
                                                                                                        62-73
 Tredgold                                                           Yaglou
10
 1836                                                               1938
                                                                                                       ASHRAE 62-81
 0
 35
       42
             49
                  56
                        63
                              70
                                    77
                                         84
                                               91
                                                     98
                                                          05
                                                                12
                                                                      19
                                                                             26
                                                                                  33
                                                                                        40
                                                                                              47
                                                                                                   54
                                                                                                         61
                                                                                                               68
                                                                                                                    75
                                                                                                                          82
                                                                                                                                89
                                                                                                                                      96
18
      18
            18
                 18
                       18
                             18
                                   18
                                        18
                                              18
                                                    18
                                                         19
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Improved Ventilation Effectiveness


• Mechanically provide filtered and
  dehumidified outdoor air to the
  breathing space
• Vary ventilation based on the
  number of occupants and process
  loads - changes in occupancy can
  be measured by CO2 sensors
• Consider designs that separate
  ventilation and space conditioning
• Utilize heat recovery systems to
  reduce system size and ventilation
  energy costs
Improved Ventilation
Effectiveness
Effective mixing of
ventilation air within space
Net positive pressure in
the southeast; exhaust
from appropriate spaces
Provide clean outdoor air,
avoid:
    loading docks
    exhaust vents
    plumbing stacks
    waste collection
    stagnant water
Acoustics
Octave Band
Directivity Factor
LEED Products

LEED-NC New Construction & Major Renovations
LEED-EB Existing Buildings
LEED-CI Commercial Interiors
LEED-CS Core & Shell
LEED-H Houses
LEED-ND Neighborhood Developments
LEED-Schools: K-12 Schools
LEED-Retail: Retail facilities- In pilot stage
LEED-Healthcare: Healthcare facilities- In pilot stage
      LEED Checklist




http://www.metrokc.gov/dnrp/summit/documents/LEED-Spataro.pdf
http://www.metrokc.gov/dnrp/summit/documents/LEED-Spataro.pdf
THANK YOU!
Additional Information /
Resources
 ASHRAE – The American Society of Heating, Refrigerating and Air-Conditioning Engineers
       www.ashrae.org
 Southface Energy Institute www.southface.org
 Geothermal heat pump consortium www.geoexchange.org
 www.buildingscience.com
 www.energycodes.gov
 HVAC Acoustics for Green Buildings Mike Filler. Ashrae technical committee for Sound and Vibration
 McQuay Application Guide AG 31-010 HVAC Acoustic Fundamentals
 Energy Efficiency in Buildings Dr. Sam C M Hui Department of Mechanical Engineering

				
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