# HVAC Basics PPT - HVAC 101

Document Sample

```					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
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
Heating and Cooling
Accuracy important!
Design conditions
R, U value
Infiltration
Occupancy schedules
Heat Transfer

Conduction
Convection
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
����   Thermal Storage
����   Heat/Energy Recovery
HVAC SYSTEMS
Heating, Ventilation and Air
Conditioning
Provides comfort for people
Allows humans to exist
Basic Refrigeration Cycle
System Types
Packaged Rooftop Unit
Split System
Air to Air Heat Pump
Water Source Heat Pump
Geothermal
VAV Variable Air Volume
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

   Individual Controllability
   Re-Configurability
   2 Extra LEED Points
   More Expensive (\$8/SF
for raised floor)
   Flexible for Change
   2 Extra LEED Points
Inland Power &
Light
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:
   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
   Height similar to rectangular
   More expensive than rectangular
Fabric Ducts

Great for certain
applications
   Gyms
   Pools
   Manufacturing
   Spokane Science
Museum
Saved \$300,000 in
   Great Diffusion   school. Lowered
chilled water temp,
   Easily Cleaned
& air temperatures
   Fun
   Same cost as
metal
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
19
19
19
19
19
19
19
19
19
19
19
19
19
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:
   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!
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

```
DOCUMENT INFO
Shared By:
Categories:
Stats:
 views: 7710 posted: 11/15/2010 language: English pages: 64