Central air conditioning does not work well.?
Question:My wife and I just bought a duplex with central air in both sides (seperate units). Unfortunately our AC seems to not work well. It was 78 degrees in the house, about 77 degrees outside. We set the AC to cool to 75, and it took about 45 minutes. Sounds like a massive waste of electricity to me. Since I have installed AC units before (with my father) I know a little about them. I changed the filter and checked the registers. Only cool air is blowing out when it comes on. I'm hoping its not a freon issue, since I remember charging units, but I cant remember which of the three hoses on the gauges go to the unit and which one goes to the tank. Any suggestions/thoughts? Thanks!
Answers:
I don't think that 45 minutes is too long a time to cool a house down by 3 degrees. It can take hours on a hot day to cool down a whole house by 6 degrees or more. You have to remember that when a house heats up, everything in it heats up, including the furniture, walls and floor, and attic insulation, and these things will continue to radiate heat into the rooms, heating up the cooler air that you're now pouring into the rooms. So more is involved than just changing the air in the rooms. (Which is the main reason it takes so long to cool off a car that's been sitting out in the sun on a hot day, as opposed to one that's been in a garage. The seats, the sheet metal, the carpeting--it's all been heated up to over 100 degrees.)
You could check the temperatures of the air where it comes out of the registers to see how cold the air really is (or isn't).
If you haven't charged the unit for a year it should be done again, especially if the units are not new. They can run low on freon even if there are no obvious leaks..
wait untill it gets hotter out. with the temp being so close usually central air/heat go 1 degree above to 1 degree below. with the temps being so close 78,77 and 75 it will take longer to cool the house, if it was 90 out you would have felt it sooner
Go outside and make sure that your air condition isn't blowing out super hot air or icing up. Either of those mean that it's got one foot in the grave. If not, have a professional come over and check the freon, it doesn't cost that much...certainly cheaper than a new air conditioner. Then get yourself a digital thermostat to make sure that you aren't wasting a ton of precious engery!
Unfortunately it does sound like a Freon issue. Try getting the manual for your specific make and model; they are usually available on the manufacturers’ website in PDF format.
Call the experts.
Joe, what you want to pay attention to is the temperature difference between the return air and the supply air.
If you have a 15 to 20 degree difference, then the AC is probably doing as good as it is going to do. If you don't have a good temperature split (less than 10-12 degree difference) then it could be;
1. dirty indoor coil
2. low refrigerant charge (signs of ice around indoor coil)
3. bad or dying blower or condenser fan motor.
If you do have a 20 degree temp split, and still can't get the house below 75 degrees, your system may be undersized.
here's a hint about the hoses- the blue gauge measures the cold temperature, and the cold pipe is usually insulated- so hook the blue gauge to the cold pipe. the middle one is for the tank.
send me a message if you need more help.
the yellow hose goes to the refrigerant bottle. the blue hose goes to the low pressure valve, low side will be larger in diameter. red hose goes to high pressure valve. keep in mind that if you over charge the condenser you could very well burn out the compressor.
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