BTU, kW and tons: converting heat pump capacity
How to go from BTU/h to kilowatts and refrigeration tons, with a table of common heat pump sizes.
Heat pumps are sold in BTU/h in Canada, European spec sheets use kW, and contractors often talk in tons. They are three units for the same thing: heating or cooling capacity.
The conversions
- 1 kW = 3,412 BTU/h (and 1,000 BTU/h ≈ 0.29 kW).
- 1 refrigeration ton = 12,000 BTU/h, about 3.5 kW.
- A BTU (British Thermal Unit) is the energy that warms one pound of water by one degree Fahrenheit.
| BTU/h | kW | Tons |
|---|---|---|
| 6,000 | 1.8 | 0.50 |
| 9,000 | 2.6 | 0.75 |
| 12,000 | 3.5 | 1.00 |
| 18,000 | 5.3 | 1.50 |
| 24,000 | 7.0 | 2.00 |
| 27,000 | 7.9 | 2.25 |
| 36,000 | 10.6 | 3.00 |
Your city’s design temperature
The heating load is calculated at your city’s design temperature, one of the coldest of the winter. That is the temperature at which the calculator checks that the heat pump covers your home.
kW of power vs kWh of energy
Do not confuse power (kW or BTU/h, what the unit can deliver at a given moment) with energy (kWh, what you pay for on your bill). A heat pump with an efficiency of 3 delivers 3 kWh of heat for 1 kWh of electricity.