Residential System seems to not cool correctly

[rickhSC]

Well, for those keeping track of weather, down here in Columbia SC the avg temperature the past few weeks has been mid to upper 90's. That being set as the ground work, it seems my Goodman Package HP unit is just not cooling as it has in the past years. Granted, it is a 1994 model, most likely beyond it's prime, but it has never given any cooling problems before. So, the stats I have taken are:

Typical outside ambient temperature in mid to upper 90's.
Return air vent ambient temperature in upper 70's (78 or 79).
Coldest vent ambient temperature mid to upper 60's (66-68).

Even now, the outside temp is 80, vent output temp is 64.

I have been told by a couple of folks that this type unit just will not handle temperatures in the upper 90's well, and that a 20 degree drop, with a 10=15 degree return to output is "within normal ranges", but for the most part, I don't remember having this much trouble in years past. I have checked the obvious.. no freezing up of coils, etc. Obviously, I don't have the equipment to test pressures, etc.

The house is under 1900 Sq Ft. 1 level, built in the late 70's. Could be much more energy efficient I am sure, although it does have a high R factor insulation in the attic. It does have a crawl space.

My guess is inefficient duct work, and maybe an old compressor getting weak.

I prefer not to waste my money or anyone's time to come out and tell me nothing is wrong, and I do understand no one here can do more that give guesses, but you guys have alot more background than I do..

Does this sound to much out of line?

Thanks!!

[hvacalex]

no, is not a 20 degree drop is 10 to 11 check for freon problem

[DavyB]

Well, for those keeping track of weather, down here in Columbia SC the avg temperature the past few weeks has been mid to upper 90's. That being set as the ground work, it seems my Goodman Package HP unit is just not cooling as it has in the past years. Granted, it is a 1994 model, most likely beyond it's prime, but it has never given any cooling problems before. So, the stats I have taken are:

Typical outside ambient temperature in mid to upper 90's.
Return air vent ambient temperature in upper 70's (78 or 79).
Coldest vent ambient temperature mid to upper 60's (66-68).

Even now, the outside temp is 80, vent output temp is 64.

I have been told by a couple of folks that this type unit just will not handle temperatures in the upper 90's well, and that a 20 degree drop, with a 10=15 degree return to output is "within normal ranges", but for the most part, I don't remember having this much trouble in years past. I have checked the obvious.. no freezing up of coils, etc. Obviously, I don't have the equipment to test pressures, etc.

The house is under 1900 Sq Ft. 1 level, built in the late 70's. Could be much more energy efficient I am sure, although it does have a high R factor insulation in the attic. It does have a crawl space.

My guess is inefficient duct work, and maybe an old compressor getting weak.

I prefer not to waste my money or anyone's time to come out and tell me nothing is wrong, and I do understand no one here can do more that give guesses, but you guys have alot more background than I do..

Does this sound to much out of line?

Thanks!!

What did your tech tell you when you serviced it?

[udarrell]

My guess is inefficient duct work,...

This will be only about what you can do to determine if something is wrong that requires a Tech.

You may well need a good service tech, let's see if we can find out...

Get a low cost humidity gauge at a hardware store, as humidity directly affects the indoor temp/split & the outdoor condenser air discharge split.

Take the temp of the outdoor condenser units discharge air & compare to the outdoor temp & indoor humidity - let us know what all those temps are.

At a 50% humidity & around 80-F indoor temp a 10 or12-SEER unit should have around a 18 to 22-Temp/Split.

If the split is much higher, it could be pulling return air from a hotter none conditioned area.

If it's much below 18-F there could be a refrigerant system problem or lack of a heatload going through the evaporator coil.

Therefore, get the humidity gauge & let us know what all the readings are including the indoor air temp split. - Darrell

[beenthere]

Have a tech come out and give it a good clean and tune.

If it cooled ok in the past. Its not a problem of it being a package unit. And probably not because your duct work is undersized(your duct is probably undersized, but not causing this problem now).

[rickhSC]

Well, temp's cooled down alot here, and just now starting back up. I took some readings today, and foundthese values:

Outside - 96 degrees, 80% Humidity
Inside Room - 76 degrees, 55% Humidity
Output cold air - 62 degrees - 75% Humidity
Return Air - 73 degrees - 70% humidity.

[skooba]

Stop wasting your time and call for a tune and clean and it will save you the headache knowing that it will be fixed instead of letting it go.

[beenthere]

Sounds like its not working right. Needs checked. To see if its pulling in outside air. And if the charge is correct.