BTU Per Hour (BTU/h)

US & ImperialCurrent unit

About 0.293 watts. The rating of air conditioners, furnaces and heaters in the US.

1 BTU per hour = 0.2930710702 watts (approximately).

About the BTU per hour

Btu per hour inherits its history from the British thermal unit, which a 1942 note in the journal Nature said apparently originated in the United States and was later adopted in Great Britain. The Btu was defined as the heat needed to raise one pound of liquid water by one degree Fahrenheit at a constant pressure of one atmosphere. Because water's heat capacity varies slightly with temperature, several versions exist, differing by up to 0.5 percent, so the unit has never been quite as tidy as the joule.

Dividing it by time gives a power unit used mainly in North America for heating and cooling equipment, and in the UK mostly for air conditioning. One watt is about 3.412 Btu/h, and one horsepower is about 2,544 Btu/h. Thousands of Btu per hour are often written MBH. Air conditioning capacity is often given in tons, where one ton of cooling is 12,000 Btu/h, about 3.52 kW, the rate needed to freeze one short ton of water into ice in 24 hours.

Sources: Wikipedia: British thermal unit; Wikipedia: Watt

BTU Per Hour conversion chart

1 BTU per hour expressed in every other power unit:

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