Anyone have a clue why my A/C will not cool?

[firedog]

Re: Anyone have a clue my my A/C will not cool?

You said water was coming from your drain line.Maybe I missed something?

More than likely the compressor was short cycling due to high discharge pressure. With the condenser fan not running there wouldn't be enough temperature drop across the condenser to get effective cooling at the evaporator, but enough to pull out some moisture. Evaporator temp would be high thus the 78 degrees or so in the house.

Glad you got it running. My compressor locked up over the weekend. seeing the system is 18 Years old, I'll just replace the whole thing.

 

[JDgreen227]

Re: Anyone have a clue my my A/C will not cool?

More than likely the compressor was short cycling due to high discharge pressure. With the condenser fan not running there wouldn't be enough temperature drop across the condenser to get effective cooling at the evaporator, but enough to pull out some moisture. Evaporator temp would be high thus the 78 degrees or so in the house.

Glad you got it running. My compressor locked up over the weekend. seeing the system is 18 Years old, I'll just replace the whole thing.

According to the serviceman I talked to, the older units that used Freon actually cool better than the newer ones that use refrigerants like R-410A and he says the cost of Freon per pound is actually less than newer types should you need to recharge an older unit. However, our older AC unit had only a SEER of 10 while the newer one has an SEER of 13. The older one we have cools about 800 square feet while the newer one has to cool about 1400 and even when running full time the newer unit can barely bring the temp down to 76 while the older unit can chill to 69 degrees. Both units are 2 ton, the problem is the newer one has to cope with a much larger unshaded roof area plus cope with the the heat gain from cooking, the fridge, all the electronics (TV, computers, etc). Wife thinks if we upsized the newer unit to a larger one it would cool better but from what I have read the larger unit would just cool things off quickly and then go thru the stop/start routine and it is better to have a slightly undersized unit.

 

[firedog]

Re: Anyone have a clue my my A/C will not cool?

Yes, the R22 does cool better than the 410A. Cost wise, I'm not seeing the R22 cheaper, plus it's due to be totally phased out by 2018.

Sizing a unit can be tricky. In addition to calculating square footage, you need to look at heat load (both internal; stove, oven, etc. and external; unshaded roof, large windows, etc.) also factor in insulation quality. You're right about to large a unit. If the run time is not long enough, the humidity is not removed, then you fell "sticky" at the same temp. plus mold can develop in the air ducts. However, too small a unit can run too long causing high electric usage. Had a nieghbor that had tremendously high electric bills, after their A/C went out, the service man told them the unit was way too small. Their old unit was a 2 ton and was replaced with a 3 1/2 ton. My daughters house is 1400 - 1450 sqft and I put a 3 ton in for them.
The unit should be able to bring the temp down, but without running continously. I can't remember the numbers, but there's a basic calculation that involves the # of cubic feet in the house, the CFM of the air handler and what percentage the system needs to run to bring the temp down a specific amount.

Last year, we replaced the upstairs unit and went from a 3 to a 3 1/2 (22 to 410A) and it's doing a fine job. Now the downstairs unit (3 1/2) is out, but I'm looking at replacing it with a 3 ton just based on the characteristic of the house plus the more energy efficient windows. Also, based on the current energy efficiencies We'll replace the gas furnace with a heat pump. (still have the gas fireplace for a backup).

 

[radioman]

just exactly where is this capacitor located for AC that sometimes fails?

 

[dmccarty]

just exactly where is this capacitor located for AC that sometimes fails?

On my Goodman unit, it is behind a panel on the upper back left of the outside unit. The back being the side closest to the house. There were four screws holding the panel in place. The capacitor on my unit was about the size of a can of beer. Obviously pull the power before messing with the capacitor. I do believe capacitors hold a charge so I would be cautious with it as well. Our capacitor had a slight bulge at the top of the can. It was not a real obvious bulge if you did not know what it SHOULD look like.

Later,
Dan

 

[RoyJackson]

Nine year old Lennox furnace and A/C unit, and no matter how much we turn down the thermostat the air coming from the registers never gets below 76 degrees. .

Any ideas? Thanks for the input.

It's probably related to all that hot air you put out...

Actually, I'm suggesting it's time to get the AC serviced. Seems like you've check about everything you can check.

 

[JDgreen227]

It's probably related to all that hot air you put out...

Actually, I'm suggesting it's time to get the AC serviced. Seems like you've check about everything you can check.

Roy, if you read all the posts in the thread you will understand what the problem actually was....but I still laughed at your post where you describe the REAL cause of it....GOOD ONE!!! :thumbsup:

And Radioman, yes the capacitors on an AC unit are outside and they DO hold a charge. What a lot of people do not know, when they mess with the innards of a microwave oven they can also get a shock out of that if they are not careful.

 

[TripleR]

When our 3 ton unit went toes up, we replaced it with a 5 ton unit and it cools great and costs less to run. We had the AC people determine the proper size.