Household appliances are a key part of our daily lives, as they make it easier and turn tasks that used to take days into hourly or even minute-long affairs. Reheating food is much easier in a microwave than on an open fire, and washing your clothes is made much simpler when you’re throwing them into a washer instead of using your elbow grease in a bucket of soapy water.
Refrigerators are also a mainstay of all our kitchens, and long gone are the days of needing to dry or salt foods to avoid spoilage. The cold environment of a fridge reduces and slows the growth of bacteria and mold on food and keeps drinks cold for those that prefer room- temperature beverages.
Even though our fridges have special features like motion sensors, edge-to-edge shelves, and even Wi-Fi and embedded TV screens, many people are unaware of just how their fridge keeps all their food cold. Here’s what you need to know about how refrigerators work.
The mechanics of a fridge are a lot simpler than you might think.
- Refrigerators require the use of a refrigerant to work, which enters the fridge through a tube-like instrument called an expansion device.
- It then evaporates from a liquid to a gas. This cools the interior of the fridge because as a liquid evaporates it absorbs heat.
- The refrigerant then flows out of the fridge through the compressor, which presses on the gas before it reaches the coils of the condenser on the outside of the fridge.
- The refrigerant then releases the heat it absorbed inside the fridge and cools back down into a liquid before then flowing back into the fridge on a continuous cycle.
- So, when you turn the temperature up or down in your refrigerator, you’re adjusting the temperature of the refrigerant rather than the actual temperature of the air in the fridge.
Refrigerators need an expansion device, compressor, evaporator and condenser coils, and the refrigerant to work.
Refrigerators used to employ the use of substances like ammonia or sulfur dioxide, but those gases were extremely flammable and potentially toxic. Nowadays, refrigerants are mostly made of hydrofluorocarbons (HFCs), or compounds that contain fluorine and hydrogen.
Unfortunately, this wouldn’t be effective. While the area directly surrounding the open fridge door may receive a temporary cooling effect, the heat entering the fridge would make the fridge work harder to cool its interior, which would eventually lead to more heat entering the fridge than what was being extracted.
The mechanics of a freezer are the same as with a fridge. The refrigerant moves from a gaseous state to a liquid back into a gas as it moves in and out of the freezer, but at a cooler temperature than a fridge.
A fridge can last anywhere from 10-20 years, but Money Pit cautions that once your fridge is about 10 years old, it can be more cost-effective to replace it than repair it.