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Thermodynamic heat pump cycles or refrigeration cycles are the conceptual and mathematical models for heat pump, air conditioning and refrigeration systems. [1] A heat pump is a mechanical system that transmits heat from one location (the "source") at a certain temperature to another location (the "sink" or "heat sink") at a higher temperature ...
cycle per second: cps ≡ 1 Hz = 1 cps = 1 Hz degree per second: deg/s ≡ 1 °/s ≡ 1/360 Hz = 0.002 7 Hz hertz (SI unit) Hz ≡ One cycle per second = 1 Hz = 1/s radian per second: rad/s ≡ 1/(2π) Hz ≈ 0.159 155 Hz: revolution per minute: rpm ≡ One rpm equals one rotation completed around a fixed axis in one minute of time. ≈ 0.104 ...
In the United States, in everyday usage the SEER is the more common measure of energy efficiency for cooling devices, as well as for heat pumps when in their heating mode. For energy-conversion heating devices their peak steady-state thermal efficiency is often stated, e.g., 'this furnace is 90% efficient', but a more detailed measure of ...
For example, an ideal fuel cell operating at a temperature of 25 °C having gaseous hydrogen and gaseous oxygen as inputs and liquid water as the output could produce a theoretical maximum amount of electrical energy of 237.129 kJ (0.06587 kWh) per gram mol (18.0154 gram) of water produced and would require 48.701 kJ (0.01353 kWh) per gram mol ...
A Carnot cycle is an ideal thermodynamic cycle proposed by French physicist Sadi Carnot in 1824 and expanded upon by others in the 1830s and 1840s. By Carnot's theorem, it provides an upper limit on the efficiency of any classical thermodynamic engine during the conversion of heat into work, or conversely, the efficiency of a refrigeration system in creating a temperature difference through ...
The coefficient of performance or COP (sometimes CP or CoP) of a heat pump, refrigerator or air conditioning system is a ratio of useful heating or cooling provided to work (energy) required. [ 1 ] [ 2 ] Higher COPs equate to higher efficiency, lower energy (power) consumption and thus lower operating costs.
For instance, a system which delivers an HSPF of 7.7 will transfer 2.25 times as much heat as electricity consumed over a season. [5] In Europe the term Seasonal Performance Factor ("SPF") is used to mean the same as the average COP over the heating season. A system which transfers 2.25 times as much heat as the electricity consumed is said to ...
The hourly ventilation rate divided by the volume of a space. For perfectly mixed air or laminar flow spaces, this is equal to the number of times per hour that the volume the space is exchanged by mechanical and natural ventilation. Also called air change rate or air exchange rate. Abbreviated ACH or ac/hr. air conditioner