Hope this is in the right section!?

I was thinking today and need an answer.

Question:
If superchargers heat up the compressed air then why does my air compressor have cool air coming out?

My Answer:
I came up with the supercharger compress the air and air compessors pump the air! Is there more or am I even close?

 

Have you ever noticed the large cooling fins on the tubes of large air compressors? They create a ton of heat. If you have a compressor with piping between the pump and the tank check how hot that tube is sometime with the compressor running. Just don't grab hold of it or you will get burned instantly.

 

??

I am talking about the compressed air not the compressors them selves

 

huge difference. an air compressor makes air by a piston and cylinder

turbo/blower spins more rpms to compress air thru passages which creates the heat

 

one air is stored in a tank, other isnt. also you ever notice you get tons of moisture out of your ocmpresor from the heat as it runs for long periods

 

The compressor itself doesn't make much heat. It's the act of compressing air that creates the heat. Much hotter than a supercharger does.

 

I guess I always thought the moisture was from cool air, but now that I think about a cold drink on a hot day it makes sense.

 

No, actually the reason is simple. Compressing a gas creates heat. Releasing pressurized gas creates cold. In the scenario you describe the compressor is forcing air into a tank, heat is being generated. When you open the air nozzle compressed gas is escaping, expanding and generating cold. It has nothing to do with pistons or rotors or anything other than a simple law of gasses.
This is the basic principle to all refrigeration.

 

Charles Law
http://en.wikipedia.org/wiki/Charles%27s_law

 

1TrueSS,

Whenever my air compressor runs the pressure line to the tank always gets pretty damn HOT! I assume that the cool air you are getting is coming from a compressor that either has a large tank, or is just starting up. With a large tank, the hot air going into the tank has a large volume to distribute heat to, generally 10 to 40 gallons depending on compressor. This would allow the heat to be distributed through out that volume of air before leaving the tank, passing through the regulator, through the hose and nozzle, and finally hitting your hand.

At that point, the air has had some contact volume for heat loss to occur, compared with a supercharger that is generally in close proximity to the point of use of compressed air, the engine. The supercharger also does not have a large air supply tank that it is feeding air into to allow the air to have a medium to cool with, although if a inter-cooler is present in the system this would help.

I hope that I am somewhat on track with this and that I have partly answered your question. If not, I am sure someone on here with more knowledge than I will take a stab at it.

It seems like everyone beat me to it, I took to long writing my post, but like others have said it's the law of expanding gas.
Chris