Heat Pump - 4 Way Valve.

[Testech]

I was wondering if anyone could help please.

I have a quick college question.

Heat Pump -

HEATING MODE - Discharge to indoor coil, indoor coil to compressor suction.

COOLING MODE - Discharge to outside coil, indoor coil to compressor suction.

When these cycles are switched how is the refrigerant metered by the TEV's ? or are the refrigerant flows bypassed and only sent through only one TEV on each cycle ? - I assume one way valves on each side and a bi-flow filter etc..

Any imput ?

[BritCit_Juve]

You will either have two metering devices (expansion valve/ accurator) in circuit one each for cooling or heating. Alternatively a two way device (capiiliary or electronic expansion valve).
In the case of the TEV they will usually each have a bypass circuit with a check valve. An accurator will only provide expansion in one direction, the expansion orriface being pushed out of the way when not required.
A capiliary is a fixed oriface and will provide the same pressure drop with flow in either direction. An electronic expansion device will regulate depending on the mode.
A biflow filter can be used but usually only a strainer is needed
Brit

[Testech]

Thankyou once again Sir !.
All the best

[icecube51]

A capiliary is a fixed oriface and will provide the same pressure drop with flow in either direction. An electronic expansion device will regulate depending on the mode.
A biflow filter can be used but usually only a strainer is needed
Brit
in addition whit the capillary there is the strainer,where inside is like a metal marble ho is correcting the flow ore amount of refrigerant.try and find an old unit and dismount it completely, open the parts as well. thats how i learned it in the old days. you understand the working parts better then.:o

Ice