AC expansion valve adjustment

[Bullet Bob]

I recently upgraded my AC system with components from Rennaire and this included new hoses, front condenser, Pro Cooler, Evaporator, and expansion valve. When I charged the system the high side pressure was at 250 psi while the low side was only 10 psi and this was at ~85 degrees ambient.

I know the expansion valce is adjustable and I think it might be a bit too restrictive at its current setting. Is there a procedure for adjusting this? The system blows cold air but the performance is not great. I haven't taken any temperature readings yet but I plan to this evening.

Thanks,
Bob

[86 911 Targa]

Bob,

With your upgrades, as we did, you should have exemplary A/C performance.

Jeff (at Rennaire) told me a while back that the expansion valves are preset to the
evaporator.

Give him a call, as I'm certain he will offer some constructive comments.

Good luck,

Gerry

[mppickett]

If you measure the temp of the large line out of the evaporator returning to the compressor, you should see 33* F if the expansion valve is set correctly.

This setting keeps the evaporator as cold as it can get without freezing up when the humidity is high. Factors that have impact on this in addition to the expansion valve are the health of the condensors, compressor and coolant charge.

[Bullet Bob]

I took some measurements and the temp at the rear condenser is 187F in, 147F out. Front condenser is 147F in, 137F out. Pro Cooler is 60F from evaporator, 87 to compressor, 137 from front condenser, 134 to evaporator. Do these make sense to anyone as for as being reasonable temps? Ther ambient temp was 101F and the vent temp is 54F. All measurements taken with a thermocouple.

[ShakinJoe]

It has an adjustment in the outlet I think it is an allen wrench. Open her up two-three turns.