Construction
BTU Room Sizing Calculator
Quick BTU sizing for AC or mini-split. Sunlight, occupancy, and kitchen heat all bump the load.
Required BTU/hr
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- Tons of cooling
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- Mini-split size
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- Window unit watts
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FAQ
Why 25 BTU/sf baseline? +
Industry rule for typical insulation + 8 ft ceilings. Old houses run 30+; new builds with great envelopes run 20.
Is bigger always better? +
No! Oversized AC short-cycles, never dehumidifies, leaves you cold-and-clammy. Manual J is the real method.