1. R3 Controls, Valves, Accessories & Heat Pumps
R3 Controls, Valves, Accessories, Heat Pumps - Subject 4 Heat Pump Operation v1.1
12/25/2018
R3 Controls, Valves, Accessories & Heat Pumps
#4 Heat Pump Operation
© 2004 Refrigeration Training Services
No reproduction or unauthorized use allowed

2. The Heart of the Heat Pump
R3 Controls, Valves, Accessories, Heat Pumps - Subject 4 Heat Pump Operation v1.1
12/25/2018
The Heart of the Heat Pump
Reversing valve:
Determines indoor/outdoor coil function
Usually energized in Cool position
Four pipes:
1 Discharge inlet (always)
1 Suction outlet (always)
2 Switch from indoor to outdoor coils
The following 2 slides show how suction and discharge gas are switched
© Refrigeration Training Services - R3 Subject 4 Heat Pump Operation v1.2
© 2004 Refrigeration Training Services
No reproduction or unauthorized use allowed

3. Reversing Valve- Cooling Mode
R3 Controls, Valves, Accessories, Heat Pumps - Subject 4 Heat Pump Operation v1.1
12/25/2018
Reversing Valve- Cooling Mode
Reversing Valve:
Heating and Cooling Modes
To Outdoor Coil
Outdoor Coil
Suction Gas (Always)
From Indoor Coil
Indoor Coil
Compressor
Discharge (Always)
© Refrigeration Training Services - R3 Subject 4 Heat Pump Operation v1.2
© 2004 Refrigeration Training Services
No reproduction or unauthorized use allowed

4. Reversing Valve- Heating Mode
R3 Controls, Valves, Accessories, Heat Pumps - Subject 4 Heat Pump Operation v1.1
Reversing Valve- Heating Mode
12/25/2018
Reversing Valve:
Heating and Cooling Modes
From Outdoor Coil
To Outdoor Coil
Suction Gas (Always)
To Indoor Coil
From Indoor Coil
Compressor
Discharge (Always)
© Refrigeration Training Services - R3 Subject 4 Heat Pump Operation v1.2
© 2004 Refrigeration Training Services
No reproduction or unauthorized use allowed

5. Heat Pump in Cooling Mode TEV system
R3 Controls, Valves, Accessories, Heat Pumps - Subject 4 Heat Pump Operation v1.1
12/25/2018
Heat Pump in Cooling Mode TEV system
Discharge gas condenses in outdoor coil
Rejects heat from indoor coil
Liquid goes to indoor coil TEV
Indoor coil vaporizes liquid
Absorbs heat from space
Vapor returns to compressor
© Refrigeration Training Services - R3 Subject 4 Heat Pump Operation v1.2
© 2004 Refrigeration Training Services
No reproduction or unauthorized use allowed

6. Heat Pump w/ TEV - Cooling Cycle
R3 Controls, Valves, Accessories, Heat Pumps - Subject 4 Heat Pump Operation v1.1
12/25/2018
Heat Pump w/ TEV - Cooling Cycle
Coil ABSORBS heat from the space
Coil REJECTS heat from the indoor coil
© Refrigeration Training Services - R3 Subject 4 Heat Pump Operation v1.2
© 2004 Refrigeration Training Services
No reproduction or unauthorized use allowed

7. Heat Pump in Heating Mode TEV system
R3 Controls, Valves, Accessories, Heat Pumps - Subject 4 Heat Pump Operation v1.1
12/25/2018
Heat Pump in Heating Mode TEV system
Discharge gas is directed to indoor coil
Uses suction line, in reversed direction
Indoor coil condenses gas to liquid
Liquid bypasses TEV through check valve
Liquid flows to outdoor coil
Uses liquid line, in reversed direction
Check valve forces liquid through outdoor TEV
Outdoor coil absorbs heat from outdoor air
Suction vapor is returned to compressor suction
© Refrigeration Training Services - R3 Subject 4 Heat Pump Operation v1.2
© 2004 Refrigeration Training Services
No reproduction or unauthorized use allowed

8. Heat Pump w/ TEV - Heating Cycle
R3 Controls, Valves, Accessories, Heat Pumps - Subject 4 Heat Pump Operation v1.1
12/25/2018
Heat Pump w/ TEV - Heating Cycle
© Refrigeration Training Services - R3 Subject 4 Heat Pump Operation v1.2
© 2004 Refrigeration Training Services
No reproduction or unauthorized use allowed

9. Heat Pump in Cooling Mode Piston metering device
R3 Controls, Valves, Accessories, Heat Pumps - Subject 4 Heat Pump Operation v1.1
12/25/2018
Heat Pump in Cooling Mode Piston metering device
Discharge gas condenses in outdoor coil
Rejects heat from indoor coil
Liquid goes to indoor coil
Piston moves out of the way in liquid line
Liquid goes through piston at indoor coil
Heat from space is absorbed in refrigerant
Vapor from indoor coil returns to compressor
© Refrigeration Training Services - R3 Subject 4 Heat Pump Operation v1.2
© 2004 Refrigeration Training Services
No reproduction or unauthorized use allowed

10. Heat Pump w/ Piston - Cooling Cycle
R3 Controls, Valves, Accessories, Heat Pumps - Subject 4 Heat Pump Operation v1.1
12/25/2018
Heat Pump w/ Piston - Cooling Cycle
© Refrigeration Training Services - R3 Subject 4 Heat Pump Operation v1.2
© 2004 Refrigeration Training Services
No reproduction or unauthorized use allowed

11. Heat Pump in Heating Mode Piston metering device
R3 Controls, Valves, Accessories, Heat Pumps - Subject 4 Heat Pump Operation v1.1
12/25/2018
Heat Pump in Heating Mode Piston metering device
Discharge gas is directed to indoor coil
Uses suction line, in reversed direction
Indoor coil condenses gas to liquid
Liquid pushes piston out of the way
Liquid flows to outdoor coil
Uses liquid line, in reversed direction
Liquid forced through piston metering device
Outdoor coil absorbs heat from outdoor air
Suction vapor is returned to compressor suction
© Refrigeration Training Services - R3 Subject 4 Heat Pump Operation v1.2
© 2004 Refrigeration Training Services
No reproduction or unauthorized use allowed

12. Heat Pump w/ Piston - Heating Cycle
R3 Controls, Valves, Accessories, Heat Pumps - Subject 4 Heat Pump Operation v1.1
12/25/2018
Heat Pump w/ Piston - Heating Cycle
© Refrigeration Training Services - R3 Subject 4 Heat Pump Operation v1.2
© 2004 Refrigeration Training Services
No reproduction or unauthorized use allowed

13. Heat Pump Defrost Cycle
R3 Controls, Valves, Accessories, Heat Pumps - Subject 4 Heat Pump Operation v1.1
Heat Pump Defrost Cycle
12/25/2018
Outdoor coil develops frosts in heating cycle
Operates 10 to 15 ° below outdoor ambient
Defrost by reversing to cooling mode:
Outdoor coil becomes a hot condenser
Outdoor fan shuts off
Indoor coil becomes an evaporator
Electric strip heaters warm air off evaporator
There is more info on heat pump defrost circuits on the Instructor CD for HVACR Electricity & Controls
© Refrigeration Training Services - R3 Subject 4 Heat Pump Operation v1.2
© 2004 Refrigeration Training Services
No reproduction or unauthorized use allowed

14. End of Heap Pumps 12/25/2018 © 2004 Refrigeration Training Services
R3 Controls, Valves, Accessories, Heat Pumps - Subject 4 Heat Pump Operation v1.1
12/25/2018
End of
Heap Pumps
© Refrigeration Training Services - R3 Subject 4 Heat Pump Operation v1.2
© 2004 Refrigeration Training Services
No reproduction or unauthorized use allowed