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The efficiency of air conditioners is often rated by the Seasonal Energy Efficiency Ratio (SEER) which is defined by the Air Conditioning, Heating, and Refrigeration Institute in its 2008 standard AHRI 210/240, ''Performance Rating of Unitary Air-Conditioning and Air-Source Heat Pump Equipment''.〔(【引用サイトリンク】 url=http://www.ahrinet.org/App_Content/ahri/files/standards%20pdfs/ANSI%20standards%20pdfs/ANSI.AHRI%20Standard%20210.240%20with%20Addenda%201%20and%202.pdf )〕 A similar standard is the European seasonal energy efficiency ratio (ESEER). The SEER rating of a unit is the cooling output during a typical cooling-season divided by the total electric energy input during the same period. The higher the unit's SEER rating the more energy efficient it is. In the U.S., the SEER is the ratio of cooling in British thermal unit (BTU) to the energy consumed in watt-hours. The coefficient of performance (COP), a more universal unit-less measure of efficiency, is discussed in the following section. For example, consider a air-conditioning unit, with a SEER of 10 BTU/W·h, operating for a total of 1000 hours during an annual cooling season (e.g., 8 hours per day for 125 days). The annual total cooling output would be: :5000 BTU/h × 8 h/day × 125 days/year = 5,000,000 BTU/year With a SEER of 10 BTU/W·h, the annual electrical energy usage would be about: :5,000,000 BTU/year / 10 BTU/(W·h) = 500,000 W·h/year The average power usage may also be calculated more simply by: :Average power = (BTU/h) / (SEER) = 5000 / 10 = 500 W If your electricity cost is 20¢/kW·h, then your cost per operating hour is: :0.5 kW * 20¢/kW·h = 10¢/h ==Relationship of SEER to EER and COP== The Energy Efficiency Ratio (EER) of a particular cooling device is the ratio of ''output'' cooling energy (in BTU) to ''input'' electrical energy (in Wh) at a given operating point. EER is generally calculated using a 95 °F outside temp and an inside (actually return air) temp of 80 °F and 50% relative humidity. The EER is related to the coefficient of performance (COP) commonly used in thermodynamics, with the primary difference being that the COP of a cooling device is unit-less, because the numerator and denominator are expressed in the same units. The SEER uses mixed units, so it doesn't have an immediate physical sense and is obtained by multiplying the COP(or EER) by the conversion factor from BTU/h to Watts: EER = 3.41214 × COP (see British thermal unit). The Seasonal Energy Efficiency Ratio (SEER) is also the COP(or EER) expressed in BTU/W·hr, but instead of being evaluated at a single operating condition, it represents the expected overall performance for a typical year's weather in a given location. The SEER is thus calculated with the same indoor temperature, but over a range of outside temperatures from to , with a certain specified percentage of time in each of 8 bins spanning 5 °F (2.8 °C). There is no allowance for different climates in this rating, which is intended to give an indication of how the EER is affected by a range of outside temperatures over the course of a cooling season. Typical EER for residential central cooling units = 0.875 × SEER. SEER is a higher value than EER for the same equipment.〔 A more detailed method for converting SEER to EER uses this formula: :EER = -0.02 × SEER² + 1.12 × SEER〔(【引用サイトリンク】url=http://www.nrel.gov/docs/fy11osti/49246.pdf )〕 Note that this method is used for benchmark modeling only and is not appropriate for all climate conditions.〔 A SEER of 13 is approximately equivalent to an EER of 11, and a COP of 3.2, which means that 3.2 units of heat are removed from indoors per unit of energy used to run the air conditioner. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Seasonal energy efficiency ratio」の詳細全文を読む スポンサード リンク
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