# BTU/hour

BTU/hour is aunit of power, measuring energy per unit time, equal to 1 BTU being output in an hour. Although the watt is the largely accepted unit for power in places that use the SI system, the BTU/hour measure is still commonly used to describe the power output of many industrial applications including steam generators, home heating (like furnaces), and air conditioning.

The BTU[1] is defined as 251.9958 calories, and due to the calorie having many different accepted values,[2] the International Table (IT) value for the calorie (where 1 calorie = 4.1868 joules) is the most commonly accepted, and is the value which this encyclopedia uses.