Heat Pump: Is a refrigeration system used to provide both heating and cooling by reversing the refrigeration system
Outdoor Coil: A component located outdoors which is used either to absorb or reject thermal energy
Indoor Coil: A component located indoors which is used to either absorb or reject thermal energy (Located in the air handler)
Compressor Section: Consists of a compressor, reversing valve, electrical wiring and controls (used in a triple split arrangement)
Reversing Valve: A device used to reverse the flow of refrigerant also called a 4 way valve.
-Conventional Systems = Energized for heating
-Non-Conventional Systems = Energized for cooling
Supplementary Heat: Used to assist the heat pump in extremely cold whether below the point where the system can no longer handle the heat loss of the conditioned area
C.O.P: Co-Efficient Of Performance: Term used to express the heating efficiency of a heat pump in the heating mode. Further defined as BTU output divided by power input (KW's converted to BTU's)
S.P.F: Seasonal Performance Factor: Term used to express the seasonal heating efficiency of a heat pump.
S.E.E.R: Seasonal Energy Efficiency Rating: Term Used to express cooling Efficiency of an A/C system BTU's/ Watt.
Examples:
Electric Resistive Heating
3412 BTU's/ KW input |
COP = 1 |
Gas Fired Heating
1100 BTU's/ Cu Ft |
COP = 0.75 to 0.90 |
Oil Fired Heating
140 000 BTU's/Gal |
COP = 0.7 |
Heat Pump Heating
6800 BTU's/ 1 KW
17060 BTU's/ 1 KW |
COP = 2 to 5 |
Heat Pump Operating Modes:
-Cooling Mode: Reversing Valve energized or de-energized
-Heating Mode: With or without AUX Heat
-Defrost Mode: Reverse cycle defrost with AUX heat energized for heating
*Note:
-Water = Constant COP
-Air = Inconsistent COP
-Night set t-stats not recommended because hot pull down is to long
-Heat pump compressors = Designed for high + low compression ratios
Heat Pump Classifications:
Heat pumps are classified by their heating source during the heating mode or cycle of operation.
The medium from which the heat pump gets its thermal energy is called heat source and the medium to which heat is rejected is called the heat sync.
Classifications of heat pumps according to the heat source
-Air to air (Common)
-Water to air (common)
-Ground to air
Heat Pump Metering Devices
-Capillary tube
-Expansion Valve (TXV)
-Actuators
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