TrowelMath

AC size for 150 square feet

  • ENERGY STAR sizing · manufacturer bag yields
  • Updated Oct 23, 2026
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150 sq ft room

The ENERGY STAR chart puts a 150 sq ft room at 5,000 BTU/hr.

SituationBTU/hr
Normal5,000
Heavily shaded (−10%)4,500
Very sunny (+10%)5,500
4 regular occupants (+1,200)6,200
Kitchen (+4,000)9,000

Worked example

A sunny 150 sq ft living room used by 3 people: 5,000 × 1.1 = 5,500, plus 600 for the third person = 6,100 BTU/hr. Round up to the nearest unit size sold.

Frequently asked questions

How many BTU for 150 sq ft?

5,000 BTU/hr (ENERGY STAR chart), adjusted for sun and occupancy.