Hi, my name is Renae. I'm an appliance repair tech, and today we're going to talk about how fridges work. So as most of you are probably aware, refrigerators have something called refrigerant, sometimes referred to as Freon, that flows through your fridge and helps keep things cool. The part that makes the refrigerant flow-through is called your compressor. Most fridge compressors are located at the back, bottom of the fridge, separate from the cavity where you keep your food because the compressor runs hot.
Inside of your fridge or freezer compartment, or sometimes both, is called an evaporator. An evaporator looks similar to the back of a window air conditioning unit. It's metal and it has a whole bunch of little fins all over it. Evaporators are one of the reasons why I wear work gloves because those fins are very sharp.
When your compressor turns on, it's going to start pumping refrigerant through some metal tubes up, in, and through your evaporator, which is going to start cooling. Now by itself, the evaporator is basically just a big block of ice. So if there were no other parts involved, food closer to the evaporator would be colder, while food further away from the evaporator might not get cold enough. So to help circulate that cold, your fridge and your freezer sections each have their own fans, usually called the evaporator fan.
Those fans usually sit somewhere right near the evaporator, and they're going to circulate cold air throughout your refrigerator so that cold can be distributed a little bit more evenly. This is why it's important not to over-pack your fridge because if your food can't get good airflow, it's not going to be cooled properly.
Once your fridge and freezer compartments reach the desired temperature, your compressor is going to turn off. And at that point, your fridge is going to go into what's called the defrost. Because during all this cooling that metal evaporator builds up a lot of frost just from all the humidity within our environment. If you let that frost build too much, it'll eventually freeze your evaporator fan in place. So your fridge will periodically go through a defrost.
Your evaporator is going to have what's called a defrost heater wrapped around the bottom of it. So during a defrost, your fridge is going to turn that defrost heater on to melt all the frost off, and underneath the evaporator and the defrost heater there's a drain pan and a hole for the water to go down into. That hole goes down into a drain pan that sits near your compressor and your condenser, which are the hot parts of your fridge.
You also have a condenser fan back there. The condenser fan blows air over the water in the drain pan which helps it evaporate, and also blows air at your compressor so that it doesn't overheat. The defrost cycle ends once your fridge hits a certain temperature, and then the whole process begins all over again. Now that you know the basics of how fridges work, stay tuned for part two where I discuss what fridge noises are normal.