Tuesday, January 15, 2008

Everday Illusions - Cold

Every Day Illusions – Cold

Did you know there are things that we take for granted, that are not really there? For example, there is cold. You may think that cold is an actual thing that you can see and feel, but not exaaactly.

In reality, cold is the absence of heat. It is merely a comparison. But you may ask what about refrigerators and air conditioners? Don’t they make cold air?

And my answer is once again, not exaaactly. Let me demonstrate:

The basic principle of refrigeration is evaporating gas cools. When you stand in front of a fan, wet, you feel much cooler. So what has happened?

The air from the fan causes the moisture on you to evaporate. And the evaporating gas takes the heat from you (along with it) as it escapes into the atmosphere.

Let’s take a look at what happens in your refrigerator or air conditioner. There are a few basic components to the system. (Please excuse the crudity of my diagram.)
1. There is a line or tubing.
2. There are two coils within the tubing.
a. evaporator coil
b. condenser coil
3. A pump (called a compressor)
4. fans at each coil
5. refrigerant (fluid that has a low boiling point)

Here is what basically happens:
1. The compressor pumps the refrigerant through the tubing.
2. As it is pumped through the system, the refrigerant is compressed.
3. This compression causes friction which produces heat.
4. Within a while the heated refrigerant begins to boil and turn into a gas
5. The gas reaches the evaporator coils and attracts heat from the surrounding area.
6. The heated gas reaches the condenser coils.
7. The fins of the coils act as a cooling system and the heated refrigerant is cooled down. The fan blows the cooled air into the cooling area.
8. As it cools it condenses and becomes a liquid and the heat is dissipated through the coils with the help of a fan. The heat escapes to the outside area.
9. The cooled liquid reaches the compressor and the cycle begins again.

So in essence, in refrigeration, the heat is removed from the air. The less heat there is, the cooler it becomes. The cold air you feel from it is air with less heat in it.

So you see there really is no such thing as cold, sorta speak. :)

My example is an oversimplified explanation. For better information on refrigeration, you can go to websites like:

Or you can just go to any good search engine and type in “refrigeration principles”.

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