Post on 02-Jan-2016
STUDY ON HVAC SYSTEMSTUDY ON HVAC SYSTEM
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HVAC SystemsHVAC SystemsTypesTypes
Several types of configurations for space Several types of configurations for space heatingheating
HVAC systems are categorized by the HVAC systems are categorized by the method used to convey energymethod used to convey energy All-air systemsAll-air systems Air-and-water systemsAir-and-water systems All-water systemsAll-water systems
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HVAC SystemsHVAC SystemsAll-Air SystemsAll-Air Systems
All heating, cooling, and humidification is All heating, cooling, and humidification is supplied to a space by the airsupplied to a space by the air Single-duct systemsSingle-duct systems
Constant volumeConstant volume Multi-zone, variable-air volume (VAV)Multi-zone, variable-air volume (VAV) Multi-zone with re-heatMulti-zone with re-heat
Dual-duct systemsDual-duct systems
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HVAC SystemsHVAC SystemsAll-Air SystemsAll-Air Systems
Single duct systemsSingle duct systemsFossil-fuel furnace with direct-expansion (DX) cooling
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HVAC SystemsHVAC SystemsAll-Air SystemsAll-Air Systems
Single duct systemsSingle duct systemsCommercial system with central heating and cooling coils
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HVAC SystemsHVAC SystemsAll-Air SystemsAll-Air Systems
Single duct systemsSingle duct systemsCommercial roof-top units
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HVAC SystemsHVAC SystemsAll-Air SystemsAll-Air Systems
Single duct systemsSingle duct systemsCommercial system with central heating and cooling coils
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HVAC SystemsHVAC SystemsAll-Air SystemsAll-Air Systems
Single duct systemsSingle duct systemsMulti-zone commercial system with variable-air volume (VAV) fan
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HVAC SystemsHVAC SystemsAll-Air SystemsAll-Air Systems
Geothermal Retrofit Suitability (Rafferty, 1998)Geothermal Retrofit Suitability (Rafferty, 1998) Low Temperature water (<150Low Temperature water (<150ooF)F)
Single-zone, multi-zone, dual ductSingle-zone, multi-zone, dual duct 8-108-10 Terminal reheat, VAVTerminal reheat, VAV 6-86-8
Standard Temperature water (180-200Standard Temperature water (180-200ooF)F) Single-zone, multi-zone, dual ductSingle-zone, multi-zone, dual duct 7-87-8 Terminal reheat, VAVTerminal reheat, VAV 6-76-7
SteamSteam Single-zone, multi-zone, dual ductSingle-zone, multi-zone, dual duct 66 Terminal reheat, VAVTerminal reheat, VAV 4-54-5
Electric resistance furnaceElectric resistance furnace 5-65-6 Air-air split heat pumpAir-air split heat pump 3-43-4 Fossil-fuel furnaceFossil-fuel furnace 4-54-5 Packaged roof-top unitPackaged roof-top unit 3-43-4 Fossil-fuel fired unit heatersFossil-fuel fired unit heaters 3-43-4www.engineersportal.inwww.engineersportal.in
HVAC SystemsHVAC SystemsAll-Water SystemsAll-Water Systems
Hot and chilled water are distributed to Hot and chilled water are distributed to terminal units and equipmentterminal units and equipment Free-standing radiatorsFree-standing radiators Baseboard radiatorsBaseboard radiators Wall, floor, ceiling panelsWall, floor, ceiling panels Fan coil unitsFan coil units
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HVAC SystemsHVAC SystemsAll-Water SystemsAll-Water Systems
Fan coil unit Unit ventilator (4-pipe)
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HVAC Components:HVAC Components: Duct SystemDuct System
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HVAC Components:
Supply DuctsSupply Ducts
Return GrilleReturn Grille
Return Return PlenumPlenum
Air Air HandlerHandler
SupplySupplyPlenuPlenumm
Duct SystemDuct System
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HVAC-induced infiltrationHVAC-induced infiltration
Infiltration ratesInfiltration rates - - Florida Duct Study 1990Florida Duct Study 1990
01020304050607080
Nu
mb
er
of
ho
uses
<0.25 0.25-0.5
0.5-0.75
0.75-1.0
1.0-1.5 1.5-2.0 >2.0
air change rate
Fan off Fan on
Duct LeakageDuct Leakage
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HVAC SystemsHVAC SystemsAll-Water SystemsAll-Water Systems
Fin tube radiator Cast iron radiator
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HVAC SystemsHVAC SystemsAll-Water SystemsAll-Water Systems
Water loop heat pump (California loop)
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Florida 50 all electric homes 13% total building
leakage in duct system
17% savings $200 cost
Duct Leakage Research 1990Duct Leakage Research 1990
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EFFECTS ON HUMAN BODYEFFECTS ON HUMAN BODY
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SummarySummary
• Selecting efficient air conditioning based on your climate.
• Selecting the proper type of and efficiency heating system for your climate
• Designing and sealing air distribution systems properly.
HVAC efficiency includes:
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