HVAC Heating ventilation and Air Condition

1. HVAC Basics
The Basics of Heating, Ventilation
and Air Conditioning
Presented by: Mark Kartchner, PE, LEED
Kartchner Engineering

2. Energy Use – Office Buildings

3. Mechanical System
Costs
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 & $3.5/SF Plumb 90,000 SF
Mechanical System Costs (Provide & Install)
8
10.5
12
14 14.5 14.5
19 20
0
5
10
15
20
25
RTU-Gas/Air
Cooled
RTU-Heat
Pumps
VAV-Elec Heat Multi Zone RTU VAV-Hot Wtr
Heat
WSHP-HP,
Boiler, Chiller,
Cooling Tow er
DOAS w / 4-
Pipe Fan Coil
Variable
Refrigerant
Volume
Dollars($)

4. 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

5. 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

6. Building Envelope

7. Load Calculations
Heating and Cooling
Accuracy important!
Design conditions
Building shell load
R, U value
Internal load
Ventilation load
Infiltration
Occupancy schedules

8. Heat Transfer
Conduction
Convection
Radiation
Resistance (R-Value)
U = 1 / R
Q = U x A x ∆T
U-Value is the rate of
heat flow in Btu/h
through a one ft2
area
when one side is 1o
F
warmer

9. Actual R-Values

10. Window Types

11. The amount of solar
heat energy allowed to
pass through a window
Example: SHGC = 0.40
Allows 40% through and
turns 60% away
Solar Heat Gain Coefficient

12. Window Properties
Energy Calculations in the Spokane region show that
reflective, and tinted windows increase energy usage on an
annual basis.

13. Energy Saving Design Methods
􀁺 Air Side Economizers
􀁺 Water Side Economizers
􀁺 Variable Frequency Drives
􀁺 Building Diversity
􀁺 Part Load Performance
􀁺 Thermal Storage
􀁺 Heat/Energy Recovery

14. HVAC
SYSTEMSHeating, Ventilation and Air
Conditioning
Provides comfort for people
Allows humans to exist
under adverse conditions.

15. Basic Refrigeration
Cycle

16. 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

17. Packaged Rooftop Units (RTU)

18. Split System

19. 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

20. Water Source Heat Pump

21. Geothermal Heat Pump Systems

22. (VAV) Variable Air Volume

23. VAV Terminal Units
Variable volume:
Parallel
Constant volume:
Series

24. 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

25. Hydronic systems
Four Pipe Fan Coil
VAV w/ HW Reheat

26. Hydronic System Major Equipment
Chillers
Boilers
Cooling Towers

27. Chilled Water System

28. Economizers
Air Side Water Side

29. Economizers
Free cooling source: When available, use cool
outdoor air instead of mechanically cooled air.
55 o
F
80 o
F
Minimum supply
of outside air
Normal Operation
Outside air dampers are
positioned to provide the
minimum outside air
Economizer Operation
Outside air dampers are fully
open. Maximum outside air is
provided
80 o
F
55 o
F and
up
85%
outside
air
85%
exhaust
HVAC-29

30. Enthalpy Wheels

31. 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

32. 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

33. 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

34. Fabric Ducts
Great for certain
applications
 Gyms
 Pools
 Manufacturing
 Spokane Science
Museum
Advantages
 Great Diffusion
 Easily Cleaned
 Fun
 Same cost as
metal
Saved $300,000 in
cost at high school.
Lowered chilled
water temp, & air
temperatures

35. Additional Equipment
Heat Exchangers
Humidifiers
Silencers

36. 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 96 does not cover)
Where are Type 1 Commercial Hoods Required?
 NFPA 96 “Cooking equipment used in processes producing
smoke and grease-laden vapors shall be equipped with…”
 NPFA 96-A-1-1 “…intended to include residential cooking
equipment where used for purposes other than residential family
use”
Type 1 Hood Clearances
 18 inches to combustible material
 3 inches to limited-combustible material
 0 inches to noncombustible material
A restaurant with a commercial gas range is
represented by the resteaurant owner to be
used ony for the preparation of soups. What
type hood is required?
Type 1 hood is for collection and removal of
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 that
commercial range. Hoods: where required,
installed at or above all commercial-type deep
fat fryers, broilers, fry grills, steam-jacketed
kettles, hot-top ranges, ovens, barbeques,
rotisseries, dishwashing machines, and
similar equipment that produces comparable
amounts of steam, smoke, grease, or heat in
a food processing establishment. Food
processing establishment shall include any
building or portion used for the processing of
food. Soup is a liquid food made up of
simmering vegetables, seasonings, and often
meat or fish. It is the potential of the
equipment (Commercial gas range), rather
than the utilization, that must be evaluated.
So, what type of hood would be required for
that commercial gas range in a restaurant
would honestly be open for discussion. You
will probably have some input from your local
Fire Dept. through plan check as with the
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
hood. Depending on the type of pizza oven,
we have allowed a type II.

37. 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.

38. Comfort
Comfort is primary
intent of HVAC
systems.
Productivity
Building Durability
Health
Mold

39. ASHRAE Comfort Zone

40. Psychrometrics
Dry bulb temp.
Wet bulb temp.
Humidity
Dew point
Moisture content
Heating
Cooling
Humidify
De-Humidify

41. Historical Minimum Ventilation
Rates (cfm/person)
0
10
20
30
40
50
60
70
1835
1842
1849
1856
1863
1870
1877
1884
1891
1898
1905
1912
1919
1926
1933
1940
1947
1954
1961
1968
1975
1982
1989
1996
Tredgold
1836
Nightengale
1865
Billings
1895
Flugge
1905
Yaglou
1938
ASHRAE
62-73
ASHRAE 62-81
Smoking 62-81
ASH-
RAE
62-89
Smoking 62-89

42. 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

43. 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

44. Acoustics

45. Octave Band

48. Directivity Factor

58. 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

59. LEED Checklist
http://www.metrokc.gov/dnrp/summit/documents/LEED-Spataro.pdf

62. http://www.metrokc.gov/dnrp/summit/documents/LEED-Spataro.pdf

63. THANK YOU!

64. 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