John Mercer asked in USMA 27038:
Could someone please tell me what the S I unit is for measureing the output of airconditioners?� In imperial it's B T U. What is the conversion factor to convert B T U's to S I?� Thanks for all your help.�������
The SI unit of energy is the joule. The Canadian Practice Guide, December 2000, give the following conversion factors between the various Btus and the joule
1 Btu (International Table) = 1 055.056 joules
1 Btu (mean) = 1 055.87 J
1 Btu (thermochemical) = 1 054.35 J
1 Btu (39"F) = 1 059.67 J
1 Btu (59"F, 15"C) = 1 054 80 J
1 Btu (65.5"F) = 1 054.615 J (This is the value adopted for use in the Canadian petroleum and natural gas industry.)
The reason for this variety of conversion factors is that the Btu involves the specific heat of water which varies with the temperature, while the joule is defined in terms of metre, kilogram and second only. The joule is the newton-metre. It is named after J. P. Joule, English physicist who researched the mechanical equivalent of heat.
