Refrigerators keep an internal temperature that is low enough to reduce and stop the growth of harmful bacteria in food. Most refrigerators work because certain substances absorb heat very efficiently as they evaporate – it’s basic physics, and it works quite efficiently!
The indispensable appliance in your kitchen works so well because it uses physics to make the most out of a small-scale heat pump. The coils on the back of your fridge make this happen, but how do they work?
The Two Coils: The Evaporator Coil & The Condenser Coil
A heat pump transfers heat energy away from a source of heat – in the fridge, this is the internal cavity – and disperses it. The appliance uses two kinds of coils to achieve this, with the first called the evaporator coil. A liquid refrigerant is pressurized and forced through an expansion valve, which evaporates it into a vapour as it enters the evaporator coil. The refrigerant evaporates inside the coil, taking out the heat energy inside the refrigerator and sending it to the next component called the compressor.
Once the compressor pressurizes the heat energy, we meet the next coil in your fridge: the condenser coil. The refrigerant vapour enters the condenser coil and condenses, regaining its form as a liquid. The condensation releases the heat energy absorbed inside the refrigerator, and it releases into the air. The liquid refrigerant circulates through the condenser coil and goes back through the expansion valve, repeating the whole process.
The system of evaporator and condenser coils has been in use for ages, but thankfully, the refrigerant that passes through them has changed. Old refrigerators used a chemical called freon, but this refrigerant was found to deplete the ozone layer, and production of freon stopped as of this year. Modern refrigerators have different products, with many models using another called HFC-134a; this is now also banned in Canada, so newer refrigerants are used.
What Can You Do To Keep The Coils Working Well?
You can maintain the fridge so that the coils can continue working at their most efficient. One way is to give them regular cleaning, as clogged coils can’t release heat as efficiently as they should. When they become clogged, the fridge’s compressor must work harder and longer than it was designed to, using more energy and shortening the life of your appliance. Most contemporary models have the coils on the back of the fridge, so to access them, you have to roll the refrigerator away from the wall.
The best thing you can do is give it a simple dusting. Loosen any dust, dirt, and debris on the coils with a brush (you can find a special brush made for coil cleaning that also works on your air conditioner and dehumidifier), vacuuming the freed dirt as you brush. Nothing more than a gentle brushing is necessary, as you must be careful not to bend the fan blades.
By maintaining the coils in this way, you can save yourself a visit from a repair person and help keep everything in your fridge as cool as possible.