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Cooling appliances

Belongs to:

Kitchenware and household appliances

Synonyms:

Freezer, Fridge, Refrigerator

Description:

Both refrigerators and freezers are considered as cooling devices.

A refrigerator is an electrical device which keeps the temperature in its interior constant between 2 - 8°C. For that purpose, the heat is extracted by heat exchangers and given off to the fridge's surroundings. The heat exchanging process can be performed in three different ways which enable a distinction between 1) compressor refrigerators, 2) absorption refrigerators and 3) refrigerators with Peltier elements. As most household and industrial fridges are compressor fridges, only this heat exchange method will be explained in the following. The compressor thereby adiabatically compresses a gaseous refrigerant which is heated as a consequence. At the back of the fridge the heat is given off to the environment through the condenser. This leads to the condensation of the refrigerant. Subsequently, it flows through a choke for pressure decrease and then into the Evaporator inside the fridge. The necessary heat for the evaporation is gained from the cooling surfaces in the fridge. Finally, the refrigerant flows back to the compressor. The compressor causes the alternating electric and magnetic fields at the fundamental frequency of 50 Hz resp. 60 Hz.

In general, fridges nowadays have an integrated freezing compartment inside or they are sold together with a small freezer as a combined device. The cooling mechanism for a freezer is similar to that of a fridge only that the target temperature is much lower, e.g. -18°C.

Frequency ranges:

• 50–60 Hz

Type of field:

electric and magnetic

Measurements (acc. to literature)

References

1. Preece AW et al. (1997): Magnetic fields from domestic appliances in the UK
2. No authors listed (2019): [Radiation and radiation protection]
3. Ainsbury EA et al. (2005): An investigation into the vector ellipticity of extremely low frequency magnetic fields from appliances in UK homes
4. Preece AW et al. (1999): Assessment of Human Exposure to Magnetic Fields Produced by Domestic Appliances
5. Kim YS et al. (1997): Exposure of Workers to Extremely Low Frequency Magnetic Fields and Electric Appliances
6. No authors listed (1992): EMF in your Environment: Magnetic Field Measurements of Everyday Electrical Devices
7. Rickli H et al. (2003): Induction ovens and electromagnetic interference: what is the risk for patients with implanted pacemakers?
8. Farag AS et al. (1998): Electromagnetic fields in the home