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Just as horsepower and candlepower were intuitive units of measure for people living through the transition from horse to steam power [3] and from flame-based to electric lighting, so was the ton of refrigeration an intuitive unit of measure during a technological change, as the ice trade gradually included growing percentages of artificial ice ...
The COP of absorption chillers can be improved by adding a second or third stage. Double and triple effect chillers are significantly more efficient than single effect chillers, and can surpass a COP of 1. They require higher pressure and higher temperature steam, but this is still a relatively small 10 pounds of steam per hour per ton of cooling.
Cooling capacity is the measure of a cooling system's ability to remove heat. [1] It is equivalent to the heat supplied to the evaporator/boiler part of the refrigeration cycle and may be called the "rate of refrigeration" or "refrigeration capacity".
(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 ...
But even ordinary units are reasonably efficient; some smaller units use less than 0.2 kWh per day (equivalent to 8 W continuously). Larger units, especially those with large freezers and icemakers, may use as much as 4 kW·h per day (equivalent to 170 W continuously).
Worldwide production of R-22 in 2008 was about 800 Gg per year, up from about 450 Gg per year in 1998. R-438A (MO-99) is a R-22 replacement. [71] R-123 HCFC-123 CHCl 2 CF 3: 2,2-Dichloro-1,1,1-trifluoroethane: 292 79 US phase-out Used in large tonnage centrifugal chiller applications.
The use of gas eliminated the need for an electric compressor motor and decreased the size of the refrigerator. However, electric companies that were customers of GE did not benefit from a gas-powered unit. Thus, GE invested in developing an electric model. In 1927, GE released the Monitor Top, the first refrigerator to run on electricity. [35]
A 3 He/ 4 He dilution refrigerator is a cryogenic device that provides continuous cooling to temperatures as low as 2 mK, with no moving parts in the low-temperature region. [ 1 ] [ 2 ] The cooling power is provided by the heat of mixing of the helium-3 and helium-4 isotopes.