What exactly is an air conditioning unit? Most all of us in modern society have experienced the benefits and comfort of conditioned air either at home, work, the mall or Movie Theater. Chances are you’ve been exposed to mechanical Air Conditioning of some sort. Do we ever stop to think about or appreciate the principles and physics behind this miraculous invention? The answer for most all of us is of course not. Like so many other niceties and conveniences that we all take for granted these days being comfortable is standard not optional.
The American Society of Heating and Refrigeration Engineers (ASHRAE), defines Air Conditioning as: “The process of treating air so as to control simultaneously its temperature, humidity, cleanliness and distribution to meet the requirements of the conditioned space. That says it all. So whether we’re adding heat in the winter or removing heat in the summer we are air conditioning.
So what exactly makes that air cold?
To answer that you must first understand that cold is lack of heat. In other words cold air is the result of having the heat removed from it. Absolute zero is -460 degrees Fahrenheit, any temperature above that can be classified as having heat. For now, we won’t go into atoms, molecules and the laws of thermodynamics but to truly understand air conditioning you must go there. When a home or building is Air Conditioned or cooled the heat inside is merely transferred or removed to a more desirable location such as outside. Heat is merely transferred it cannot be destroyed.
A more suitable name for an air conditioner may be heat mover or heat remover. Sounds strange but by design that’s what an air conditioner does. It moves heat from one place to another. Example: From inside your home, to the world outside. Another simple example would be your refrigerator. It does not destroy the heat to make the inside of the refrigerator cold. The heat is just removed from the refrigerated space and released outside or actually into your home. If you’ve ever felt the heat coming out from the back or bottom front of your fridge you’re feeling the heat being removed from inside the box. Isn’t that just great, now your air conditioner has more heat to remove?
The process of cooling your home in the summer does not involve creating cold air but instead removing or moving the heat from inside your home and releasing it outside. The means by which this is accomplished involves transferring the heat with the use refrigerants such as R-22 commonly referred to as Freon or R-410A sometimes referred to as Puron. Actually it’s a little more complicated than that but we’ll happily be drilling down deeper into the physics and principles of Air Conditioning and Refrigeration in future articles. So stay tuned and stay cool!