12,000 BTU is exactly one ton of cooling, the unit HVAC contractors think in. It is the largest window AC most people can run on a normal 115 V outlet and the best-selling single-zone mini-split size. In an average room it cools up to about 600 sq ft, with a best fit of 500 to 600 sq ft. The Energy Star chart is more cautious and puts it at 450 to 550 sq ft.
A shaded, well insulated room stretches to about 740 sq ft; a sunny, poorly insulated one stops around 470; a 10 ft ceiling brings it to 480.
Open floor plans are where a 12,000 BTU unit gets asked to do too much. If a 600 sq ft living room is open to the kitchen, add 4,000 BTU for the cooking load and the space needs about 16,000 BTU/hr. That is 18,000 BTU territory, not 12,000, and a unit that runs flat out all afternoon without catching up is the usual symptom.
As heat, 12,000 BTU covers about 300 sq ft in a moderate climate, 400 in a hot one and 210 in a cold one. A 12,000 BTU window unit draws about 1,090 W, 9.5 A at 115 V. Converted, it is 3.52 kW (sold as a 3.5 kW split outside the US) and 3,517 W.
How many square feet a 12,000 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 | 740 sq ft |
| Average room (baseline) | 600 sq ft |
| Very sunny, poor insulation | 470 sq ft |
| Hot climate, very sunny | 490 sq ft |
| 10 ft ceiling | 480 sq ft |
| 4 people instead of 2 | 540 sq ft |
| Kitchen in the space | 400 sq ft |
How many square feet 12,000 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 | 330 sq ft | 400 sq ft | 470 sq ft |
| moderate | 250 sq ft | 300 sq ft | 350 sq ft |
| cold | 180 sq ft | 210 sq ft | 250 sq ft |
12,000 BTU in kW, watts and tons
| Kilowatts | 3.52 kW |
| Watts | 3,517 W |
| Tons of cooling | 1.00 tons |
| Power an AC this size draws (EER 11) | about 1,091 W, 9.5 A at 115 V |
| Power an electric heater needs for this output | 3,517 W, 14.7 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.
12,000 BTU questions
How many square feet does a 12,000 BTU air conditioner cool?
About 600 sq ft in an average room, with a best fit of 500 to 600. Shaded and well insulated, up to about 740; sunny and poorly insulated, about 470. The Energy Star chart is more cautious at 450 to 550.
Is 12,000 BTU one ton?
Yes. A ton of cooling is defined as 12,000 BTU/hr, the rate of heat it takes to melt one ton of ice in 24 hours.
What is 12,000 BTU in kW?
3.52 kW. A 3.5 kW split system listed in Europe or Australia is the same size as a US 12,000 BTU mini-split.