NFT: A/C Question For All Of You Handymen

[KC Dan]

Originally Posted by The Rick

Just tried turning on the A/C yesterday for the first time this year and I got little air coming out of the vents and it didn't feel all that cold. My first thought was to change the air filter so I did that. Now, more air comes out, but it's not cold. The thermostat is set at 78 degrees, but the temperature in the house won't go below 85 degrees.

I don't know much about A/C, but I did take a look at the outside unit. The fan was running, but I'm not sure if it continuously runs. After doing a little research on the Internet, I called my wife to have her check the two pipes coming out of the outside unit. I read that one should be cool and one should be warm if everything is working properly. Based on what she told me, both pipes were warm.

Anyone here know anything about air conditioning? What would cause only lukewarm air to come out and not cool air? Freon problem?

If both tubes (i assume from the compressor) are warm, then you most likely have a problem. Generally, you will never get air from the unit that is more then 19-20 deg. cooler than outside air. So if the temp outside is 100deg, you wont see less than 80deg from the A/C inside. Make sure the fans come on and if the outside fan isn't coming on then the air will never cool down inside. Also, the compressor should cycle when the A/C is on. If when the temp inside is above the thermostat and you don't hear the compressor humming outside, its not on and either dead, has overloads that tripped or an electrical problem. If the outside fan doesn't come on, its only a matter of time until the compressor buys the farm. Lastly, do the stupid check and make sure your switch on the thermostat is on auto and cool selected. You have no idea how many times that I have seen the thermostat set wrong. Even by smart people.

[Lzen]

Originally Posted by KC Dan

If both tubes (i assume from the compressor) are warm, then you most likely have a problem. Generally, you will never get air from the unit that is more then 19-20 deg. cooler than outside air. So if the temp outside is 100deg, you wont see less than 80deg from the A/C inside. Make sure the fans come on and if the outside fan isn't coming on then the air will never cool down inside. Also, the compressor should cycle when the A/C is on. If when the temp inside is above the thermostat and you don't hear the compressor humming outside, its not on and either dead, has overloads that tripped or an electrical problem. If the outside fan doesn't come on, its only a matter of time until the compressor buys the farm. Lastly, do the stupid check and make sure your switch on the thermostat is on auto and cool selected. You have no idea how many times that I have seen the thermostat set wrong. Even by smart people.

I take it you do this stuff for a living?

[KC Dan]

Originally Posted by Lzen

I take it you do this stuff for a living?

I used to. I was trained by the best A/C - Refrig man in So. Cal - My dad. He had his own business for many years and trounced the big companies there. In fact, while in Cali in January I did 2 service calls for my brother. One was the twit had the unit set to heat and couldn't understand why it wouldn't get cold. The other - the condensor fan went out and the unit was on without it eventually burning up the compressor. See, the fan outside is your condener fan, as the freon gas moves through the coils from the compressor it gives up its heat by radiating it to the cooler ambient air outside the coils. The condensor fan speeds up the radiation of heat by blowing ambient air over the condensor coils. And, if the condensor fan doesn't help move the warm air away from the coils, the evaporator air won't get much cooler because no heat has been removed by the condener. Thank God I don't do calls anymore, too many stupid people. They don't clean filters/replace them or wash out the condenser coils.