How many square feet does a one ton air conditioning unit cool?

Answer 1

Most air-conditioners generate about 400 CFM per ton, but don't confuse Square Feet with Cubic Feet. A sunny South-facing room (SF) will take more CFM to cool than the same size room facing North.

A very rough idea is:

- For and older drafty, inefficient house 400SF per ton. Any sizing larger than this should be explained by the contractor.

- For a newer reasonably built house 600SF per ton.

- For an Energy Star Qualified house 600-800SF per ton.

- Well designed, thoughtfully crafted houses can achieve 800-1200 SF per ton.

Bigger is not better - getting the right size is important. About 70% of the work of the air conditioner is to remove the humidity from the air - this is called the latent load. An oversized unit will bring the temperature down quickly but not remove the humidity. A right-sized unit will run longer and do a better job with dehumidification allowing you to keep the set-point several degrees warmer and still achieve the comfort level expected.