HVAC School

Refrigeration Basics

Posted by: Hvac at February 4th, 2009

To start things off here at the HVAC School I might as well make sure that you know the basic principles of refrigeration. You will not be learning anything here that will get you EPA 608 certified, you will not learn how to fix anything, but you will get a great amount of knowledge as to how the cooling and heating process work, it will surely help you out in the future if you do decide to go to a real accredited HVAC school that is for sure.

To get a little bit on the scientific side of refrigeration I will start with the word “cold”. When it comes to science law and all that other crap “cold” does not exist until you get to absolute zero, which is -460 degrees Fahrenheit. This is the point where all atomic motion comes to an end, there is not energy. No one here on earth has ever achieved this temperature, we have came less than a degree away but just haven’t quite put the nail in the coffin. Okay maybe a little off subject of HVAC School and the principles of cold and heat, or is it?

You would like to think that when your air conditioning system is up and running that it is just blowing cool air everywhere, and that is why the rooms are getting cold. The same as when your refrigerator and freezer are running, to the average person they are just blowing really cool air, therefore the space is staying cool. Well if you are to be a certified experienced HVAC technician, and you do decide to go to an HVAC school to learn a career that you can take with you anywhere you will learn that this is not how stuff works. This is not how the refrigeration cycle works, where would you get the cold air from?

When it comes to air conditioning and refrigeration, the process of cooling is actually the removal of heat. For instance inside a freezer, heat is being pulled out of the freezer and ran over coils that are filed with high pressure refrigerant which absorbs the heat and dumps it out right outside the box. The same thing and exact same principle comes into effect with air conditioning systems.

Now when it comes to heat, the fact is that heat will always move to where it is less warm. Another thing that you will learn in any HVAC School that knows what the hell they are talking about. For example if you have 2 anvils that are next to each other, one is at room temperature and the other is burning hot at over a thousand degrees, the ambient temperature anvil will absorb the heat from the hot one until both temperatures on the anvils equalize. This is just how heat and cold work.

Now with that being said heat will always travel to the cooler spot, nothing can stop it, nothing. But we can slow it down through means of insulation, kind of like your refrigerator and freezer doors have insulation stripping on them. Ovens are also equipped with a type of insulation around the door to slow the heat inside of the oven from escaping to the cooler air. So how do air conditioning systems and refrigerators remove heat so efficient? The answer is through refrigerant.

When a liquid boils it lets of the heat that is trapped in the liquid, meaning the liquid turns into steam, which is just letting off some heat. If you were to have two buckets of water that were sitting side by side outside in the hot sun, and one of them was covered and the other was not, the one that was covered would have a lot more heat. The uncovered one would be a lot cooler as it would be letting off heat with the steam escaping.

This is what you will need to know if you ever want to pass those tests in certain HVAC schools that do extensive training on this type of stuff. I do agree that hands on training is the best and most efficient type of training there is when it comes to learning about HVAC, but this is information that every technician and teacher in the HVAC field should know and be aware of. If they do not then they do not know what the hell they are talking about.

Refrigerants will boil at a much cooler rate than water does, for instance R-22 boils at negative 40 degrees Fahrenheit, which makes it a superb choice for a liquid that can remove heat. This is the very basics of refrigeration and the principles that you will learn in any HVAC school.