How to Size a Air Conditioner Unit?

Sizing your AC unit for your home:

There are variables in sizing and AC unit:

  • Age of Home, Bungalow or 2 story, furnace air flow.
  • When considering Square footage allow for main floor and above. Basements are not part of the calculation.
  • A typical Bungalow will use a larger unit than a s story because of roof sizing.
  • If your home was built before 1995 and is still original allow 1 ton per every 600 sqft
    • Example 1900sq foot bungalow would use 3 ton as it does not get to the next 1/2
  • For a multi story home you can use 1 ton for every 800 sq ft
    • Example 1900 sqft2 story home would be 2.5 ton  

Some rules to consider:

  • It is better to be slightly undersized or exact size than over sized.
  • An over-sized unit will short cycle causing increased electrical use and potentially poor cooling quality.

Measure from where the condensing unit unit will be potentially to the furnace location for line length.