30,000 BTU is 2.5 tons: a central air system for a small house, a multi-zone mini-split outdoor unit, or a gas unit heater for a large garage or shop. As cooling in an average space it covers up to about 1,500 sq ft, with a best fit of 1,200 to 1,500 sq ft. The Energy Star room chart gives 1,500 to 2,000 sq ft.
A shaded, well insulated space stretches to about 1,850 sq ft; a sunny, poorly insulated one stops around 1,180. With multi-zone systems, a 30,000 BTU outdoor unit is often paired with indoor heads that add up to more than 30,000, for example 9,000 + 9,000 + 12,000. That works because rooms rarely need full cooling at the same moment, but no head gets its full rating while all of them run hard.
As heat, 30,000 BTU covers about 750 sq ft of insulated space in a moderate climate, 1,000 in a hot one and 540 in a cold one. In a poorly insulated garage or shop, it covers about 620 sq ft in a moderate climate and 450 in a cold one, which makes it a common pick for a two-car garage in the north.
At an EER of 11 a 30,000 BTU unit draws about 2,730 W, 11.9 A at 230 V; modern high-efficiency systems draw less. Converted, 30,000 BTU/hr is 8.79 kW, 8,792 W or 2.5 tons.
How many square feet a 30,000 BTU air conditioner cools
Largest room the unit keeps up with, rounded down to the nearest 10 sq ft. Two occupants, 8 ft ceiling and moderate climate unless the row says otherwise.
| Room | Cools up to |
|---|---|
| Shaded, good insulation | 1,850 sq ft |
| Average room (baseline) | 1,500 sq ft |
| Very sunny, poor insulation | 1,180 sq ft |
| Hot climate, very sunny | 1,230 sq ft |
| 10 ft ceiling | 1,200 sq ft |
| 4 people instead of 2 | 1,440 sq ft |
| Kitchen in the space | 1,300 sq ft |
How many square feet 30,000 BTU of heat covers
By climate and insulation. For a gas heater, use its output rating (input × efficiency).
| Climate | Poor insulation | Average insulation | Good insulation |
|---|---|---|---|
| hot | 830 sq ft | 1,000 sq ft | 1,170 sq ft |
| moderate | 620 sq ft | 750 sq ft | 880 sq ft |
| cold | 450 sq ft | 540 sq ft | 640 sq ft |
30,000 BTU in kW, watts and tons
| Kilowatts | 8.79 kW |
| Watts | 8,792 W |
| Tons of cooling | 2.50 tons |
| Power an AC this size draws (EER 11) | about 2,727 W, 11.9 A at 230 V |
| Power an electric heater needs for this output | 8,792 W, 36.6 A at 240 V |
kW and watts here are heat output, the number on the box. An air conditioner moves that much heat while drawing far less electricity; an electric heater draws exactly as much as it puts out.
30,000 BTU questions
How many square feet does a 30,000 BTU air conditioner cool?
About 1,500 sq ft of open space in average conditions, with a best fit of 1,200 to 1,500. Shaded and well insulated, up to about 1,850; sunny and poorly insulated, about 1,180.
Is 30,000 BTU 2.5 tons?
Yes. 30,000 ÷ 12,000 = 2.5 tons.
How big a garage will a 30,000 BTU heater heat?
About 620 sq ft if the garage is poorly insulated and you live in a moderate climate, and about 450 sq ft in a cold climate. An insulated garage in a moderate climate goes to about 750 sq ft.