To size your mini split air conditioner, the most important thing you need to know is the square footage of the room you’re looking to cool and/or heat. Each indoor unit will be capable of providing a set number of BTU’s of cooling and heating power. In order to size your mini split correctly, you will need to know the square footage of the room, and check it against our table.
For multi-zone systems, you will need individual air handlers for each room, with the specified BTU. Take the total BTU of the indoor heads, to establish the total outdoor capacity needed.
BTU Sizing Chart for Mini Split Systems
Check out our square footage and BTU comparison chart below. The following table is for individual zones, for a multi-zone, combine the total BTU’s needed to establish the overall BTU values of the system.
| Area To Be Cooled | Capacity Needed (BTUs Per Hour) |
| 150 to 250 square feet | 6,000 BTUs |
| 250 to 300 square feet | 7,000 BTUs |
| 300 to 350 square feet | 8,000 BTUs |
| 350 to 400 square feet | 9,000 BTUs |
| 400 to 450 square feet | 10,000 BTUs |
| 450 to 550 square feet | 12,000 BTUs |
| 550 to 700 square feet | 14,000 BTUs |
| 700 to 1,000 square feet | 18,000 BTUs |
| 1,000 to 1,200 square feet | 21,000 BTUs |
| 1,200 to 1,400 square feet | 23,000 BTUs |
| Up to 1,500 square feet | 24,000 BTUs |
Environmental Factors
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