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Gunner33 05-27-2012 07:38 AM

1 year old Central Air not working properly
Hello. Last year we built a house with central air. Our first summer the unit would cool the house 4 degrees easily in an hour. This spring when we turned it on it wasn't working. The hvac guy came and added coolant and "torqued" the system. Now, it only cools the house 1 degree an hour and it has not even reached 90 degrees yet! The hvac guy says this is "normal" but I disagree after reading on the internet that central air systems should cool 3 degrees an hour under standard conditions and based on what the ac unit did last summer. He plugs his little device into the compressor and always says "our numbers look good." Our warranty ends in a month so I would like to have some ideas for our hvac guy to try out so I don't have to end up paying out of pocket to get it working properly in the future since it's only 1 year old. I can only imagine how it is going to work once the truly hot weather comes! We are very frustrated at this point and feel like since the hvac guy is not going to make any money that he doesn't want to do anything. Thank you for any suggestions.

qbert 05-27-2012 10:45 AM

Ask him where did the coolant go.

clocert 05-27-2012 11:54 AM

You should not just add coolent without ask him why as mentioned by qbert (because there is a leak). The way to measure if your AC is good or not, do the following: Measure the temp of the register cold air comes in to the house and the temp of the return air. the difference should be at least 15 or 16 degrees, good newer AC may get to 18 or 19 degrees.

ben's plumbing 05-27-2012 04:28 PM

there is a leak in your system..and must be fixed and retested for proper operation of system...:yes: mentioned where did freon system should not need freon.....oh unless its leaking.....

Gunner33 05-27-2012 05:59 PM

I think you guys are spot on...
So I did the temperature difference test and there was only a 9 degree difference between the two registers...not even close to 15 degrees!!! There has got to be a leak. Today it was in the mid 80's with low humidity and it ran for about 2 and a half before it would shut off at 71 degrees. Also, there is condensation on one of the thicker of the pipes leading into the condensor...I'm not sure if that's normal of if that is a problem. BTW, it is a HEIL unit, which from the internet does not get good ratings. Do any of you use HEIL stuff or do you stay away? Thanks again!

beenthere 05-27-2012 06:07 PM

Common for the large line to sweat.

plummen 05-27-2012 09:36 PM

Id tell him you want the whole system leak checked/pumped down then charge recheck system.
Sounds like Carrier/Bryant/Heil leaking coil curse to me,at same time the installer doesnt sound too bright either though! :wink:

carmon 05-27-2012 11:17 PM

I concure......:thumbsup:

clocert 05-27-2012 11:55 PM

Condensation on large line is a good sign. Large line should feel cold. But how about the small line ? hand touch the small line, and let us know if it is cold, warm, hot, or...

Gunner33 05-28-2012 11:52 AM

The temperature of the small line doesn't really feel warm or cold...seems to be the same as the air temp...83 degrees.

clocert 05-28-2012 07:49 PM

Small line feels a little warm, that's good too. Are you sure the large line is cold? feels like a glass of ice water ?? If both lines temp are OK, small line warm, large line cold, then you should get better than 9 degree split.
Also make sure all your filters/coils are clean, and all duct are well sealed, no leak.
One more thing to check : the air blow out of the condenser should be 10-12 degrees higher then the ambient temp. This is all you can do. If all OK, next thing to do is call a pro to put the gauges on the system to check the line pressures.

Gunner33 05-29-2012 03:29 PM

One more question...what temperature should the air blowing out of the vents be? I've heard it should be a minimum of 55 degrees. Mine is blowing at 61 degrees...thanks.

Marty S. 05-29-2012 04:50 PM

15-22 degrees colder than it's sucking in. Check at the furnace,not the registers.

Gunner33 05-29-2012 07:47 PM

So how many degrees per hour should the unit be cooling the house? I read on the internet that it should be cooling 3-4 degrees per hour under standard conditions. Thanks.

clocert 05-30-2012 12:22 AM

3 or 4 degrees is the norm, but that depends on many factors: insulation, size of the house, size of the AC, type of windows, Sun, outside temp, etc..

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