Direct answer
A 150 sq ft room starts near 3,000 BTU/h before real-world adjustments.
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What Size AC for 150 Sq Ft?
Worked room AC sizing example for a 150 sq ft room.
Sources and maintained assumptions
Sizing assumptions are centralized and show source URLs, check dates and notes.
- DOE Room Air Conditioners
Checked 2026-05-22. Used for room AC preliminary BTU rule, room-level sizing caveats and oversizing humidity cautions.
- DOE Portable Air Conditioners Test Procedure
Checked 2026-05-22. Used for portable AC SACC / label caveats.
- ENERGY STAR Certified Dehumidifiers
Checked 2026-05-22. Used for pints/day and product rating caveats.
- HVI Bathroom Ventilation
Checked 2026-05-22. Used for residential bathroom fan CFM rules and fixture model.
- ACCA Technical Manuals
Checked 2026-05-22. Used to define Manual J, Manual S and Manual D boundaries.
- EPA Mold and Indoor Air Guidance
Checked 2026-05-22. Used for mold and water intrusion disclaimers.