British thermal unit
Physical unit | |
---|---|
Unit name | British thermal unit |
Unit symbol | |
Physical quantity (s) | (Thermal) energy |
Formula symbol | |
dimension | |
system | Anglo-American system of measurement |
In SI units | |
Derived from | Fahrenheit degrees , pounds sterling |
The British thermal unit is a unit of energy . Your unit symbol is BTU or Btu , its symbols W . The Btu does not belong to the International System of Units (SI) and is defined as the heat energy required to heat a pound of water by 1 degree Fahrenheit . Since this energy differs depending on the temperature of the water due to the temperature-dependent heat capacity , there are several definitions of the Btu.
The International (Steam) Table Btu was defined as 1055.05585262 joules according to the International (Steam) Table Calorie (cal _{IT} ) .
... Btu | ... joules | calorie | ... watt hour |
---|---|---|---|
1 Btu _{IT} | 1055,05585262 J. | ≈ 252 cal | |
1 MBtu = 1,000 Btu | ≈ 293,071.070.159.3 Wh | ||
1 therm = 100,000 Btu | |||
1 MMBtu _{IT} = 1,000,000 Btu _{IT} | 1055.05585262 MJ | ≈ 293.071.070.159.3 kWh = 0.293.071.070.159.3 MWh |
When specifying heat pumps (especially air conditioning systems ), the cooling capacity (incorrectly) is often given in Btu for imported devices. What is meant here is BTU per hour (BTU / h).
- 1000 BTU / h ≈ 293 W.
The power dissipated in heat is also given in BTU / h for devices to be cooled in data centers .
The natural gas -Consumption is sometimes in MMBtu (million British thermal units; MM comes from a thousand thousand) indicated. 1 MMBtu corresponds to 26.4 cubic meters of gas, based on an energy content of 40 MJ / m³ (11 kWh / m³).
The units Quad (quadrillion British thermal units) and Therm are derived from Btu .
Individual evidence
- ↑ sizes.com: British thermal unit