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Travis Jordan
 
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Default AC Advice Needed!

unix-freak wrote:
I assume you mean "There's not much condensation from the evaporator
(inside) coil..."

Yeah...that's what I meant. I actually opened up the plenum and
there's plenty of water. I didn't do anything as far as coil
cleaning. I guess I could spray it down with the proper coil cleaner.
I also made sure that the PVC wasn't clogged while I was there.

The most common causes of low delta-T a

1) undercharged refrigerant due to a leak

I had a different tech out last summer and he said that the charge
was fine, so that's 2 techs that have had their guages on it saying
it's fine.


2) excessive air flow over evaporator (i.e.air handler fan set to
wrong speed)

I double checked it, and it's wired for high with the heater wired
for low.

3) dirty condenser coil

There are other less-common things that go wrong such as problems
with the thermal expansion valve (TXV), bad compressor valves, bad
reversing valve, and more. About the only thing you can do as a
homeowner is check the outside coil to make sure it is clean. If it
is, you really need to call a qualified serviceperson (I would
submit that the one you called last time who recommended a larger
unit is not among the list of service people to talk to).

Please post back when you have a final resolution.


Oh...one more thing. It's 88 outside right now and my compressor just
cut off on it's own even though the fan is still running and the
thermostat set to auto. It did that yesterday and I had to turn off
power to it for 10 minutes, then it came back after that. I know in
automotive ac, the clutch with kick off if the charge is low.


It is also possible that the compressor is overheating and shutting down
on overtemperature. If the system were just low on refrigerant (and it
had an auto-reset low-pressure switch installed, a feature seen mostly
on high-end systems) then indeed it might restart after 10 minutes. How
ever, I wouldn't risk compressor damage if I were you.

Tomorrow morning call one of the local HVAC distributors and ask the
counter person for the name of a really good technician that they would
have work on their personal system. Johnstone Supply will do if you
have one in the area, or find the distributor for the manufacturer of
your system.