400 sq ft room
The ENERGY STAR chart puts a 400 sq ft room at 9,000 BTU/hr.
| Situation | BTU/hr |
|---|---|
| Normal | 9,000 |
| Heavily shaded (−10%) | 8,100 |
| Very sunny (+10%) | 9,900 |
| 4 regular occupants (+1,200) | 10,200 |
| Kitchen (+4,000) | 13,000 |
Worked example
A sunny 400 sq ft living room used by 3 people: 9,000 × 1.1 = 9,900, plus 600 for the third person = 10,500 BTU/hr. Round up to the nearest unit size sold.
Frequently asked questions
How many BTU for 400 sq ft?
9,000 BTU/hr (ENERGY STAR chart), adjusted for sun and occupancy.