STUDY ON HVAC SYSTEM STUDY ON HVAC SYSTEM

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


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



Single duct systemsSingle duct systemsFossil-fuel furnace with direct-expansion (DX) cooling



Single duct systemsSingle duct systemsCommercial system with central heating and cooling coils



Single duct systemsSingle duct systemsCommercial roof-top units



Single duct systemsSingle duct systemsCommercial system with central heating and cooling coils



Single duct systemsSingle duct systemsMulti-zone commercial system with variable-air volume (VAV) fan



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



Fan coil unit Unit ventilator (4-pipe)


HVAC Components:HVAC Components: Duct SystemDuct System


HVAC Components:

Supply DuctsSupply Ducts

Return GrilleReturn Grille

Return Return PlenumPlenum

Air Air HandlerHandler

SupplySupplyPlenuPlenumm

Duct SystemDuct System


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



Fin tube radiator Cast iron radiator



Water loop heat pump (California loop)


Florida 50 all electric homes 13% total building

leakage in duct system

17% savings $200 cost

Duct Leakage Research 1990Duct Leakage Research 1990


EFFECTS ON HUMAN BODYEFFECTS ON HUMAN BODY


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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STUDY ON HVAC SYSTEM STUDY ON HVAC SYSTEM