Any air conditioning folks in the house???? (Home A/C)

[redgtxdi]

So I don't know what to even be looking for and my A/C unit works pretty good.......BUT.........


While the A/C compressor (outside the house) works properly, the fan inside is a dual speed setup. It kicks high or low supposedly depending on what it senses the incoming air is doing??? (I'm guessing from past memory)

Anyway.........the last couple years during the summer time that sucker kicks HARD high, then low, then high, then low. Actually, I'd love it to just stay high (heat, for example only uses one speed....'high'.....of the two, but the a/c uses both speeds) but I know that the A/C process is a little more complicated due to moisture in the air, cooling rate, etc.


Anybody know what the problem might be???


(FWIW, it's a Lennox a/c unit, and central fan. Compressor sits outside the house and fan unit sits in the attic)

 

[NoShangriLa]

What is your thermal stat set at?
Make sure there is a gap between heat & cooling mode because the heat pump will continuously go from heat mode to cool mode if the temperature are set too close of a range.

Heat is generally set between 62-64, and cooling mode is 68-74 (72 is common). Normally, blower/fan is set to run low in heating mode and high in cooling mode.

Also, check your blower to see if it is function correctly, and make sure the filters & ducting pathway isn't obstruct.

Good luck!

 

[boomerang]

I had nearly the exact same symptoms with a Carrier system installed a year ago. Mine differed in that it did it during the heating cycles. After many phone calls by me and numerous trips out by tech's it ended up being a circuit board in the furnace itself.

 

[edro]

The two speeds are used for better humidity control on the A/C side.
You need slower moving air across the coil to dehumidify more efficiently.

If the setting is always on high for A/C, you will get a "cold clammy" feeling, as your temperature will be low, but humidity will be high.

As for why it keeps changing from High to Low, I do not know.
Perhaps the humidity set point is right on the hair's edge and the control keeps switching it over.

 

[redgtxdi]

Thanks guys. Pretty much follows my train of thought too.


I know that it works plenty well......(assuming that the home design originally included a "Manual J" to properly estimate cooling needs)......so I guess I'm just hoping it doesn't bounce around so much that it pulverizes whatever kind of 'clutch' the fan uses to switch from hi to low.