Central Air Sizing

Hey all

What would you say the minimum sized AC unit for a 3000 square foot house would be?


Well, that’s why the make HVAC techs…:wink:

…but a loose rule of thumb is 700/800 square feet per ton depending on your climate.

1/4 ton per 1,000 sf, Barrow, AK.

Do a search on this subject. There is plenty posted.

If you would like to make a guess and use tonnage per sf, make sure your insurance is paid up.

Around here the guess is 400 sf per ton. As Larry said, depends where your at and how houses are constructed.


There all right. Leave sizing to the Pro’s.

Too many variables (ie:state energy code-design criteria; home plan design and construction methods - orientation, insulation, windows & doors, finishes, internal loads) just to name a few.

Unless you are willing to do the math, stay away from sizing. There are too many variables. Here in Fla, the rule of thumb is 550 square feet per ton.

Northern U.S. and Canada it 700 to 1000 square feet for 1 ton

Insulation, tightness and SEER all have to be considered. It would be best to use a Manual J for such calculations. Even then…:roll: :roll: