Toolyard

BTU Calculator

How to size an air conditioner

  1. Choose square feet or square metres and enter the floor area and ceiling height.
  2. Choose how sunny the room is.
  3. Enter the number of people and tick Kitchen if it is one.

Frequently asked questions

How is it worked out?

About 20 BTU/h per square foot for an 8 ft ceiling, 10% less for shaded rooms and 10% more for sunny ones, 600 BTU/h for each person beyond two and 4,000 BTU/h for a kitchen.

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