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boug_j
28-11-2006, 01:19 AM
I have A 2 Ton air conditioning unit which i replaced with a 2 Ton Heat pump, i left the same evaporator, the evaporator has an orifice valve .057, do i need to replace it with a TXV ? or the orifice valve will work with the heat pump. Thanks for the advice
Jim

LRAC
28-11-2006, 07:31 AM
Hi Boug j

This could pose a real problem depending on the original age of the unit and what it is. I presume all the change over gear is on the outdoor unit and the original coil controls the expansion side of the business(liquid line system).

One area to check is if the orifice is bi-directional, If other forum members reccomend a TXV then a bypass of the TXV may need to be installed when on heating i.e check valve.

Worth checking to see if the new outdoor unit has the capabilty to convert the system to expansion lines instead of liquid. If so the orifice can be removed completely.

Hope it goes well
Regards
Lrac

monkey spanners
28-11-2006, 05:17 PM
Many heatpumps (wallmounts cassettes undercieling/floormounts) have a sensor or a stat on the indoor coil to turn the outdoor fan off in heating mode if the indoor coil gets to hot to stop any heat damage to the plastic parts (drainpan coil mounting etc) The sensor presumably would turn off the compressor also if the coil was still getting to hot. Might be something to look at depending on what your working on.

Cheers Jon

boug_j
29-11-2006, 12:05 AM
Thanks to all of you.
Jim

Larry2
01-12-2006, 01:41 AM
I have much the same question on auto heat/air conditioning. I have an old car that I would like to cancel the heater core and replace it with an evaporator and reversing valve. It would clean up the tight quarters under the hood. Immediate heat would be wonderful on cold mornings.