Search results
Results from the WOW.Com Content Network
The therm (symbol, thm) is a non-SI unit of heat energy equal to 100,000 British thermal units (BTU), [1] and approximately 105 megajoules, 29.3 kilowatt-hours, 25,200 kilocalories and 25.2 thermies. One therm is the energy content of approximately 100 cubic feet (2.83 cubic metres) of natural gas at standard temperature and pressure .
The Btu should not be confused with the Board of Trade Unit (BTU), an obsolete UK synonym for kilowatt hour (1 kW⋅h or 3,412 Btu). The Btu is often used to express the conversion-efficiency of heat into electrical energy in power plants. Figures are quoted in terms of the quantity of heat in Btu required to generate 1 kW⋅h of electrical energy.
In the United States, U-value is expressed as British thermal units (Btu) per hour-square feet-degrees Fahrenheit: Btu/(h⋅ft 2 ⋅°F) Within this article, U-values are expressed in SI unless otherwise noted. To convert from SI to US customary values, divide by 5.678. [1]
In those contexts, the unit of heat capacity is 1 BTU/°R ≈ 1900 J/K. [5] The BTU was in fact defined so that the average heat capacity of one pound of water would be 1 BTU/°F. In this regard, with respect to mass, note conversion of 1 Btu/lb⋅°R ≈ 4,187 J/kg⋅K [6] and the calorie (below).
Energy; system unit code (alternative) symbol or abbrev. notes sample default conversion combinations SI: yottajoule: YJ YJ 1.0 YJ (2.8 × 10 17 kWh) zettajoule: ZJ ZJ 1.0 ZJ (2.8 × 10 14 kWh)
British thermal unit: Btu Btu 1.0 Btu (1.1 kJ) BTU BTU million British thermal units: MMBtu MMBtu 1.0 MMBtu (1.1 GJ) e6BTU BTU British thermal unit (IT) Btu-IT Btu IT ...
The BTU was originally defined so that the average specific heat capacity of water would be 1 BTU/lb⋅°F. [19] Note the value's similarity to that of the calorie - 4187 J/kg⋅°C ≈ 4184 J/kg⋅°C (~.07%) - as they are essentially measuring the same energy, using water as a basis reference, scaled to their systems' respective lbs and °F ...
BTU IT /h ≡ 1 BTU IT /h ≈ 0.293 071 W: BTU (International Table) per minute: BTU IT /min ≡ 1 BTU IT /min ≈ 17.584 264 W: BTU (International Table) per second: BTU IT /s ≡ 1 BTU IT /s = 1.055 055 852 62 × 10 3 W: calorie (International Table) per second: cal IT /s ≡ 1 cal IT /s = 4.1868 W: erg per second: erg/s ≡ 1 erg/s = 10 −7 ...