Specifications

IM 1049-4 / Page 31 of 36
Typical Refrigeration Cycles
Figure 45: Cooling Mode – (Single Circuit Only Shown)
Return Air
Reversing Valve
Conditioned Air – (Cooling)
Thermal
Expansion Valve
Co-Axial Heat
Exchanger
Blower
Coil – Air to Refrigerant
Heat Exchanger
Water In
Water Out
Sensing Bulb and
Capillary Tube
Compressor
Cooling Refrigeration Cycle
WhenthewallthermostatiscallingforCOOLING,thereversingvalvedirectstheowoftherefrigerant,ahotgas,leavingthe
compressortothewater-to-refrigerantheatexchanger.Heretheheatisremovedbythewaterandthehotgascondensestobecome
aliquid.Theliquidthenowsthroughathermalexpansionmeteringsystemtotheair-to-refrigerantheatexchangercoil.Theliq-
uidthenevaporatesbecomingagas,atthesametimeabsorbingheatandcoolingtheairpassingoverthesurfacesofthecoil.The
refrigerantthenowsasalowpressuregasthroughthereversingvalveandbacktothesuctionsideofthecompressortocomplete
the cycle.
Figure 46: Heating Mode – (Single Circuit Only Shown)
Return Air
Thermal
Expansion Valve
Co-Axial Heat
Exchanger
Reversing Valve
Conditioned Air – (Heating)
Blower
Water In
Water Out
Sensing Bulb
and Capillary Tube
Compressor
Coil – Air to Refrigerant
Heat Exchanger
Heating Refrigeration Cycle
WhenthewallthermostatiscallingforHEATING,thereversingvalvedirectstheowoftherefrigerant,ahotgas,leavingthe
compressortotheair-to-refrigerantheatexchangercoil.Heretheheatisremovedbytheairpassingoverthesurfacesofthecoil
andthehotgascondensestobecomealiquid.Theliquidthenowsthroughacapillarythermalexpansionmeteringsystemtothe
water-to-refrigerantheatexchanger.Theliquidthenevaporatesbecomingagas,atthesametimeabsorbingheatandcoolingthe
water.Therefrigerantthenowsasalowpressuregasthroughthereversingvalveandbacktothesuctionsideofthecompressor
to complete the cycle.