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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.
For example, if using Btu/kWh, use a conversion factor of 3,412 Btu per kWh to calculate the efficiency factor. For example, if the heat rate is 10,500 Btu/kWh, the efficiency is 32.5% (since 3,412 Btu / 10,500 Btu = 32.5%). The higher the heat rate (i.e. the more energy input that is required to produce one unit of electric output), the lower ...
Example: For a heat pump delivering 120,000,000 BTU during the season, when consuming 15,000 kWh, the HSPF can be calculated as : HSPF = 120000000 (BTU) / (1000) / 15000 (kWh) HSPF = 8. The HSPF is related to the non-dimensional Coefficient of Performance (COP) for a heat pump, which measures the ratio of heat delivered to work done by the ...
(72,000 BTU/h) × (1000 h/year) × ($0.12/kW·h) ÷ (10 BTU/W·h) ÷ (1000 W/kW) = $860/year. Example 2. A residence near Chicago has an air conditioner with a cooling capacity of 4 tons and an SEER rating of 10. The unit is operated 120 days each year for 8 hours per day (960 hours per year), and the electric energy cost is $0.10 per kilowatt ...
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. However ...
So, for a boiler that produces 210 kW (or 700,000 BTU/h) output for each 300 kW (or 1,000,000 BTU/h) heat-equivalent input, its thermal efficiency is 210/300 = 0.70, or 70%. This means that 30% of the energy is lost to the environment. An electric resistance heater has a thermal efficiency close to 100%. [8]
It was originally defined as the rate of heat transfer that results in the freezing or melting of 1 short ton (2,000 lb; 907 kg) of pure ice at 0 °C (32 °F) in 24 hours. [1] [2] The modern definition is exactly 12,000 Btu IT /h (3.516853 kW). Air-conditioning and refrigeration equipment capacity in the U.S. is often specified in "tons" (of ...
Heating degree day (HDD) is a measurement designed to quantify the demand for energy needed to heat a building. HDD is derived from measurements of outside air temperature . The estimated average heating energy requirements for a given building at a specific location are considered to be directly proportional to the number of HDD at that location.