I rent an apartment and the ac will not cool below 80.  The temperature of the air coming out of the vents is 68.  I have called maintenance twice and they have checked it out.  It is full of freon, or whatever they use now, the coils were just cleaned and the filter is clean.  This is an old ac unit and an old apartment building.  I know I lose a lot of cool air out of the windows, but what else can be done?  New unit outisde that is bigger?  I am hot and it sucks being hot at home.

Is this a "package" unit (like hotel/motels use) or a small dx unit w/ seperate condenser and air handler section?

if it is the latter--

Does it not cool at all, or only a little? Does it cool more when it first comes on, or after a few minutes? Does the fan blow as hard as it should? Is there any way to punch a small (just big enough to stick a small cooking thermometer in, like 1/8" diameter) in the duct IMMEDIATELY downstream of where the air handler ties into the ductwork? If so, note the temp there...and it would be real nice if you could figure out what the evaporater temp is..(could be a faulty expansion valve). Also,  feel of the small line (liquid line) outside, by the condenser. It should be slightly above ambient (outside) temp. The larger line (suction), if it has a bare spot that is not insulated, should be sweating (water collecting on the outside and running off). Depending on a couple of things (superheat) , this line should be cool. That's a real REAL general way to see if the charge is OK.

It's real hard to diagnose stuff like this without being there. And really easy for me to forget something and look like an idiot over the WWW for trying to diagnose without being there!!

I have an indoor and outdoor unit, and they are old as dirt.  The air blows as fast as it does in winter, I have gas heat.  It cools a little bit, but it cant deal with warm temperatures.  I am not sure of the air coming out of the air handler, but the air coming out of the vents is 68, measured by a good thermometer.  I guess I will just call them to come and fix it every day until I get a new unit.

As a "rule of thumb" .... measure the return air of your unit (hot air going into the furnace/air handler unit) you've already told us your discharge air temp is 68 degrees.... You should get a MINIMUM of 15 degrees and preferably 20 degree temperature drop.... so if you have 80 degrees room temp (return air) and a 68 degree discharge temp you are only getting 12 degrees temp change.... so it REALLY does need help. Have you checked your filters recently ? Is the outdoor unit coils kept clean? Keep calling them... it's still not right.

Thanks for the help guys, both times the return temp was 80 and 68 discharge.  Today he cleaned the coils on the indoor unit, and the air filter is clean.  He also said that he has even overcharged the system with freon, or whatever it is called.  He said he has it charged at 65, I guess that means pounds?

Also I this place has old windows so I know I am losing cool air, but I know other people have cool apartments here so I should be able to sit at home and not sweat while watching tv.

Read this thread:

www.ar15.com/lite/topic.html?b=1&f=139&t=587803

I learned it all the hard way.