The absorption refrigerator is a refrigerator that utilizes a heat (e.g., solar, kerosene-fueled flame) source to provide the energy needed to drive the cooling system rather than being dependent on electricity to run a compressor. These refrigerators are popular where electricity is unreliable, costly, or unavailable, where noise from the compressor is problematic, or where surplus heat is available, e.g., from turbine exhausts or industrial processes. Absorption refrigerators, powered by liquefied petroleum gas, are also used for food storage in recreational vehicles.
Absorptive refrigeration uses a source of heat to provide the energy needed to drive the cooling process. The most common use is in commercial climate control and cooling of machinery. Absorptive refrigeration is also used to air-condition buildings using the waste heat from a gas turbine or water heater. The process is very efficient, since the gas turbine produces electricity, hot water and air-conditioning (see Trigeneration).
A single-pressure absorption refrigerator uses three substances: ammonia, hydrogen gas, and water, whereas large industrial units generally use only two, a refrigerant such as ammonia, and an absorbent such as water (with an expansion valve and pump, not described here). Normally, ammonia is a gas at room temperature (with a boiling point of -33 °C), but the system is pressurized to the point that the ammonia is a liquid at room temperature.
The absorption refrigerator was invented by Baltzar von Platen and Carl Munters in 1922, while they were still students at the Royal Institute of Technology in Stockholm, Sweden. Commercial production began in 1923 by the newly formed company AB Arctic, which was bought by Electrolux in 1925.
In Swedish:
- Baltzar von Platen and Carl Munters, Om alstring av kyla (1925)
