DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (
-   HVAC (
-   -   Physical size of Central AC unit (

Marjorie 06-19-2010 11:16 PM

Physical size of Central AC unit
I just had a 2.5 ton Trane XL15iAC unit installed (my house is about 1,400 square feet) and it is enormous. If it is so efficient why is it so big? I t seems to me that a unit that big would use more electricity. I keep reading about being careful not to oversize the AC. Does this not apply to the actual size of the unit?

Red Squirrel 06-19-2010 11:20 PM

I don't know much about ACs, but maybe it's efficient because the coils themselves are bigger, making the unit itself bigger. I would imagine if the condenser coil covers a larger surface area, it will cool off better, making the compressor work less hard. I might be full of it though, I'm no expert, just speculating.

beenthere 06-20-2010 06:43 AM

It is as Red said.

The larger coil surface area. Aids in rejecting heat better. So a smaller horse power fan is used. Which draws less wattage.
A lower head pressure means a lower compression ratio, so the compressor draws less wattage.

All times are GMT -5. The time now is 05:59 PM.