britishthermalunit
nounUK /ˌbrɪtɪʃ ˈθɜːməl ˈjuːnɪt/
US /ˌbrɪtɪʃ ˈθɝːməl ˈjuːnɪt/
A British thermal unit is a small amount of heat energy used to measure how much heat something has.
The heater gives off about 20,000 British thermal units every hour.
OTHER MEANINGS
2. A unit of heat equal to the amount needed to raise one pound of water by one degree Fahrenheit.
One British thermal unit is roughly 1,055 joules.
3. A measure used to describe the energy output of heating and cooling systems.
The air conditioner is rated at 12,000 British thermal units.
4. A standard unit in the imperial system for quantifying heat energy.
Engineers compared the fuel's British thermal units to its cost.