House Central A/C

I have a "heat pump" central unit installed in my house.
Wife is complaining it needs repair because it runs for very long extended periods during the hot part of the day.
I tried to tell her we live in a older house with poor insulation and the air coming out of the vents is normal cool. Outside temperature has been in the mid to upper 90's everyday with very high humidity.
While I know upgrading the house insulation will help she insist something is wrong with the A/C unit.

To keep the peace I have taken apart the inside unit and cleaned the coils; and have also cleaned the coils on the outside unit. Air inlet filter is brand new.

Before calling out a service man I want to put a set of gauges on it to see for myself if just maybe the freon is a little low. Problem is I do not know what readings are normal.
If it makes a difference the outside unit is a Goodman <a href="http://www.alpinehomeair.com/related/Goodman%20CPLT%20Series%20Spec%20Sheet.pdf">CPLT142-1B</a> 3.5 ton and the inside unit is a <a href="http://www.alpinehomeair.com/related/Goodman%20AEPT-AEPF%20Specs.pdf">AEPT060-OOC-1A</a> with variable speed fan motor. This is a R22 system.


So can one of you A/C guys tell me what would be normal reading for this unit????

There is no way to tell you what the normal reading would be without knowing outdoor temp, indoor temp, liquid line temp, or superheat. There should be a charging chart on the inside cover of the outdoor unit. Unless you know what you are doing and have the necessary test insturments you will probably do more harm than good by putting a set of gauges on the unit. I am not saying that you don't know how to check one but every time you remove a gauge hose you lose some freon. I would say that the unit may be slightly undersized for your house is why it runs all the time. A guesstimation of pressures would be: Indoor temp of 72 degrees- suction pressure 72-76 degrees. Outdoor temp of 95degrees head pressure around 220-230 degrees. With the new higher seer units you cannot guess. You have a 13 seer unit. The newer units are charged by weight for a matching air handler and outdoor unit, plus length of the lineset. DH

if the unit is perfectly sized then it will run all day non stop any day in the high 90's to maintain mid 70's in the house. this will be the most effecient it can run. Only on 5-7 days a year should the inside temp rise to 80 for more than 2 hours. This means the unit is removing the most moisture out of the air it can and cooling your house as cheaply as it can be done. If your unit is cycling on and off then you are using more electricity every time it starts and not keeping the inside coil cold enough to properly dehumidify.
an oversized unit will kick on and drop the temp fast. however it will not run long enough to remove moisture from the air and it will feel clamy inside. it will also cost more to operate.
good luck
Ron

Its not the Ac its the wife, may not be much you can do. Try telling her it needs to run a lot in this kind of weather to dehumidify the house. Its not all about cold its also humidity here in the midwest. I have 2 heatpumps in this old house and one is oversized therefore the downstairs doesnt dehumidify like it should. I would trade you mine for one that runs a lot more.

As previously stated the heat pump is operating 100% normal for a correct sized unit on a hot day.
Time to tune up the wife instead of the heat pump.
Don't let her shut the unit off and open the windows at night letting humidity in. The heat pump works harder removing humidity than cooling the air.

[i:654c4848f0]Don't let her shut the unit off and open the windows at night letting humidity in[/i:654c4848f0]

Not likely. We turn or A/C on in march or april and the windows never open again till late september or maybe even october. We have not been below 75 deg in over 20 days.

Thanks for the help guys.
It has been very humid and really hot this year.
I did notice that the drain tube has a constant drip no matter how long the unit runs so it is most likely a good thing that it runs most of the time.

another thing you can do is check the air temp on the supply registers and the intake register. see how many degrees difference there is. 10 degree diff would be normal for a old ineffecient unit. I have seen some window units wit close to 20 degree diff and you should have something inbetween 10 and 20.