Air Conditioning - A/C won't cool everything test fine

Our central air will not cool the house. The other day it was 76 outside and 84 in here after running it for an hour. Freon is not low and there is no leak in the system. the coil was removed and cleaned, and air temp at the duct was roughly 68 today when it was 85 outside. Everything seems to working but the house just will not cool. The Tech tried to tell me its just the way our place is set up and theres nothing that can be done. Obviously he's an idiot as the air worked here the last two years we lived here and I can only assume it worked the 25 or so before that or someone would have fixed it. Also there are 54 other identical units and I haven't heard anyone else complain.

So anyone have any ideas?

Alot of variables.

A 27 yr old system is quite old. Feel the larger of the two copper lines coming out of the compressor, it should be cold and have condensation on it. The other one should be warm/hot.

This same thing happened to my 25 yr old system. Just started to not cool the house properly. The system gets weaker over the years. I ended up replacing everything.

Set your thermostat at a temperature which you normally find comfortable & leave it there. Don't turn it off & expect the A/C to drop the temp in an hour. Ain't gonna happen. Normal temperature drop is about 15-20º between the air going in & what is coming out of the unit. Checking temps at the registers is not the place to check. The temps need to be checked at the air handler.

wee have left it on for days, it will hit 76 at night but it starts going up as soon as it gets warmer outside. The air only keeps the house about 1 or 2 degrees cooler than the outside and sometimes its actually warmer in the house than outside.

Sorry, I was under the impression you had just turned it on. I think you need a new tech. Something is most definately wrong.

the third tech from this company just left. His current repair was to replace the freon saying the stuff that was in there was contaminated with water. Hopefully this works....It does seem to have dropped about 2 degrees in the last hour but the real test won't be until tomorrow when it starts getting hot out again. Luckily I complained very loudly after the first $550 repair that did not do anything so all subsequent repairs have been free.

If no refrigerant has been added in the past, this guy's blowing smoke. I hope he vacuumed the system very well & installed a filter/dryer.