Common Types Of Refrigerators

Igloo Cool Chill 40 The Igloo brand Cool Chill 40 thermoelectric refrigerator.

Think that if you’ve seen one refrigerator, you’ve seen them all? You’d be surprised! Over the past couple of centuries, various types of refrigeration techniques have been invented for both food storage and air conditioning needs.

The most common of these types is the one that’s probably in your own home. Nearly all domestic refrigerators on the market are compression style refrigerators. This design uses a heat pump or compressor to apply pressure to refrigerant along its refrigeration cycle. The refrigerant gas enters the compressor carrying the heat absorbed from the food compartments. The pressure applied by the compressor causes the gas to boil and release the heat once it enters the condensing coils. Compressor refrigerators have become the standard method of refrigerator due to their efficiency, though they’re also most famous for being the noisiest design.

You may have noticed that smaller refrigerators (like the tiny ones built to hold 6-packs of soda cans) are much quieter. Sometimes known as "Peltier coolers", these use thermoelectric cooling; a means of directing temperature using electrical current. Even though they are quieter than their kitchen-sized counterparts, they also consume far more electricity. This expensive requirement has kept their use limited to small coolers for camping or college dorms.

Zeer Pot-In-Pot Cooler An example of a zeer pot-in-pot cooler.

Most alternative forms of refrigerators tend to exhibit variations of absorption refrigeration. Absorption refrigerators use no electricity, with the only needed power coming from a heat source. This has made them the most "green" refrigeration solution, with engineers hard at work to make the technology efficient enough to compete with mainstream compression refrigerators. This type of refrigerator was also the base for Einstein’s refrigerator design.

The most recent form of refrigerator was invented in 1995 by Mohammed Bah Abba, a teacher from Nigeria. He invented the zeer (or pot-in-pot refrigerator) while looking for an inexpensive way of extending the freshness of food for small third-world communities with little to no access to electricity. The zeer consists of a small pot placed inside of a larger pot with sand filling the gap in between. Water is then poured into the sand until it’s saturated and a damp cloth is placed over the top of the small pot. As the water evaporates, it carries away surrounding heat, keeping the contents inside the small pot cool. For his invention, Mohammed Bah Abba was awarded the Rolex Laureate in 2000.