I live in an upstairs apartment in Houston. My a/c is not cooling off the apartment. If cools off at night, but increases throughout the day, beginning around 10 am. I have all blinds closed, a ceiling fan in the bedroom, and an oscillating fan in the living room. I have not been running the dryer or the dishwasher during the day. Maintenance checked the freon and said it was fine. A contractor came and added extra freon, but said the unit, while older, seemed to be running OK. He told me the temperature should definitely not be climbing up so much. As soon as he left, the temperature started to creep up. For the past 3 days, I have set the control at 70, yet the temp inside has increased to over 81. ( If I set it at 78, which is what I prefer, the temperature inside rises into the high 80s). Right now it's 83 and rising. The temp right at the vent is 75. Maintenance checked the freon again today, then called the contractor back, and he'll be returning on Monday. The seem feel to the outside unit is OK.

Am I crazy to think there's something wrong? Shouldn't the a/c be able to work harder to keep up? Isn't an increase in temp from 76 to 83 between the hours of 10 and for a little excessive?

The vent temp should be much cooler than 75. Have them check the coils for cleanliness. Also is your air filter clean?

The air filter was changed on Monday.

Good. Now have them check the coils. Dirty coils can cause problems

I'll be sure to ask them to do that when the come back. Thanks!

A simple check to find out if the a/c is working close to normal is to take a thermometer and measure the air temp. entering the furnace and air temp. leaving the furnace, the difference should be about 20 degrees. This temp. can be taken at the return grill and the vent closest to the furnace. Let us know, thanks.

OK, is the return grill where the a/c filter is? And I have no idea what the furnace is... can you clarify a bit? Thanks!

Yes where the filter is and then check the vent on the ceiling or wall, don't worry about the location of the furnace.

The difference between the 2 seems to be about 12-13 degrees

This indicates it is not cooling properly, could be low on refrigerant, mention this to them when they come to check it, also ask them if they washed the outdoor unit , it could be running a high head pressure, Mike

The freon has been checked 4 times this week so far- 3 times by maintenance and once by a contractor. Is it probable that because it's an older unit (at least 13 years old) it just isn't able to keep up any more? It has been getting progressively worse over the past few summers, but never to this extent. And all out summers are hot here in Houston.

Also, when the contractor checked the temp coming out of the vent the other morning, it was 70 and he said that was fine. I thought I read in a few posts that it was supposed to be much cooler than that?

Thanks for you patience with my lack of knowledge. I'm just getting super frustrated with this situation that I've been trying to get resolved since Monday.

There is a chance that the compressor has bad valves which would affect the capacity of the a/c and cause the a/c problems that you have ,this can be checked by a service person if the condensing unit (outside unit) has service valves on it ,most do. I would ask them to check for bad valves also. You might have to ask for a different service co.if they can't fix it . 70 degrees from the vent is on the high side, should be closer to 60 degrees.