That air inside the refrigerator is now at about 45 degrees. We need to remove heat from it, to bring it back down to 40 degrees. How do we do that?
We have to bring it into contact with something with a much lower temperature than 40 degrees.
That thing is Freon®.
What Is Freon®?
To put it simply, Freon® is a fluid, like water. And like water, it can exist as a liquid or a gas (gaseous water is called steam.)
You can make the temperature of a fluid increase or decrease Simply by adding heat to it or taking heat away from it.
There are several different kinds of Freon®. There are also other kinds of fluid refrigerant that are NOT Freon®. To keep the lawyers happy, I will explain that below.
But for now, what you need to know is that Freon® is the fluid that moves heat around the refrigerator.
As it moves around the refrigerator, it is constantly changing temperature, pressure and state, from a cold gas (at about 14 degrees) to a hot gas (at about 150 degrees) to a hot liquid (at about 120 degrees,) and back to a cold gas.
Also as it travels around the system, it absorbs heat from the freezer (keeping the freezer cold) and gives off heat to the ambient air around the outside of the refrigerator (the heat has to go somewhere, right?)
The tubing and compressor within the refrigerator containing the Freon® is known as the “sealed system.”
So back to the original question, how do we remove heat from 45 degree air? The answer is, we put it in contact with cold Freon® gas at about 14 degrees, so the heat flows from the cold air into the colder Freon®.
But there’s a problem there; we can’t mix the two gases. We have to find a way to have them touch each other, so heat can flow from the air to the Freon®, without them mixing.
More About Freon®
Freon® is actually a registered trademark for a specific group of fluid refrigerants, like R-12, R-13B1, R-22, R-502 and R-503.
There are other kinds of liquid refrigerants that are not Freon®, such as R-134a and R-414b, that your refrigerator may use.
But you will not be doing sealed system (Freon®) work with these instructions. So for simplicity’s sake, throughout this text, I am going to call the refrigerant Freon®, whether or not it is actually Freon®.
Kinda like I would call facial tissue “Kleenex,” just to make it easier to type, read and understand.