fan versus low freon

[hankus]

Living along the hot Gulf Coast we need good AC.The upstairs unit in my 1995 house had to be recharged in 2004 by AC Guy (AG) and a few weeks later the downstairs unit fan wouldn't turn on even when the thermostat batteries were replaced. AG said that the fan was burnt out and replaced it and all was well.A few weeks ago the upstairs fan would go from blowing vigorously to a puny exhaust.I would turn it off and in a few hours on retstart it was as strong as ever for a while and then revert to puny state.AG came out and felt the motor which was hot (17 hours of continuous running) and said I needed a new motor.I had to go out of town so i postponed it...and upon further reflection had my wife turn both units on .The 4 hour rest produced a strong blast from the upstairs unit which is measuring 81-83 in various ducts and the downstairs one is 50-53 in various ducts.AG hadn't measured duct exhasut temp. I suspect that because the lower one doesn't blow cold that it runs too long,overheats and then can't push hard.AG has been contacted,refuses to only rcharge with freon and insists a new motor is needed Thanks for your feedback

Hal

[udarrell]

If you let it get extremely hot in the conditioned space, ducts in attic NOT properly insulated etc., you will end up with high discharge air temps. (In the low 80's is a bit far out)

Perhaps the A/C Guy picked up (bought) a new motor for it, & does not want wait long to resell it.

Get a different A/C Guy, - get an A/C Tech this time! - udarrell

[Al Moran]

You're welcome!

[Noon-Air]

Where on the gulf coast???

FWIW, 95% of the calls I get start off with "My air conditioners not working, it needs FREON". Most of the time, lack of refrigerant is not the problem. When the system *is* low on refrigerant, it leaked out somewhere and its a really good idea to get it repaired. It does sound like you need to find a good tech to properly diagnose and correct all of the problems on your systems. At this point, from what you have posted, I don't believe that a bad blower motor is the problem

[Stormin Mormon]

I've had much the same experience. Remembering one call where the fellow had a 3.5 ton split system. But not cooling. He's thinking if

3.5 isn't doing the job, he needs 5.0 tons. I asked him to let me do the needed repairs, and then he found out the 3.5 did a good job cooling his house. I knew what was needed, but even after I described the problem, he still didn't believe me. I had to actually get the cold air pumping, and then he probably still wasn't sure that I did that all without a shot of that there freezon stuff.

[Bob Pietrangelo]

Stormy,

did you do a load calc?

[Murdentech]

Make your AC guy agree that if he replaces the motor and it doesn't fix the problem he will refund your money in full, including the cost of the motor. Then he can come fix the problem again and you will pay him within 30 days after that, provided the unit is working properly. If he balks at that, find a new AC guy.

[Stormin Mormon]

No, I did not.

[Travis Jordan]

Most likely cause: system low on refrigerant due to a leak.

[Zephyr]

Bingo!

[Dido]

excuses me I am little slow but what air flow got to do with refrigerant how about explain that: Dido

[Danny G.]

8) Hahahahahahahahaha

[Stormin Mormon]

When an AC system is running, the expanding freon is trying to absorb some rate of heat. Measured in BTU per hour. If the air flow is low, it will chill the air too cold (and might freeze). If the air flow is too high, it won't make the air cold enough.

Low air flow is more likely to freeze the cold coil. Oddly enough, low freon also creates a lower temperature, and is likely to freeze the coil.

A combination of the two can also freeze a coil. Which further reduces the air flow, and then you rapidly end up with NO air flow.

The original poster some days ago mentioned having reduced air flow, turning off the system, and then the air flow resumed. Which is a good sign of frozen evaporator.

Hope that helps.

[Al Moran]

What a total waste of skin.

[Oscar_Lives]

Airflow chills the coil? Low airflow chills the coil?

So if you let all the freon out, it will freeze up solid?

Turning the system off makes the fan start running?

[Bob_Loblaw]

Explain to us how you manage to get a paycheque every week? You must be blackmailing the owner!

[Danny G.]

8) Hahahahahahahaha #2.

[Stormin Mormon]

I'm never sure if I should take Oscar seriously. So, I have chosen not to.

[Dido]

First of all I work for my self and I do not gave customer a snow job as you and some others do! but truth some times they may not like it but in long run has dividends and most of my work is repeated customers if you are interested what I do and on what I work check these companies Thermotron, Cincinnati sub zero, Thermal product solution, Tenney Engineering, Blue M, Standard Environment, Associated environmental, LR environmental, Sales Associates, SowLow, American research, Webber(good for crap), and few others ETC.

Eat and whip my friend DIDO

[Bob_Loblaw]

"Dido" wrote

you mean call-backs??