BTU stands for British Thermal Unit. It is an american / English unit of energy . In which joule is its SI meyric unit equivalent.
Basically a BTU is a unit of thermal energy.
Its defined in old imperial units as the energy to raise the temperature of a given weight of water by a specific number of degrees Farenheit.
Usually we use BTU/hr in EI units to quantify the heat dissipation / transmission of a material. and / or in Air conditionning.
1 kW of heat power = 3142 BTU / hr
12,000 BTU / hr = 1 Ton = 3417 Watts of heat power dissipation / transfer.
BTU meters measure the energy content of liquid flow in British thermal units (BTU), a basic measure of thermal energy.
BTU meters are used in chilled water systems for both commercial and industrial and office buildings. These meters are used to bill users for energy usage.
Energy = V x ΔΘ x k.
V is the supplied water volume
ΔΘ is the temperature difference measured
k is the thermal coefficient of water