So, it would be ummmm a reverse cycle airconditioner?

well today i discovered there are 2 different types yes paul just like yours the demotic we were working on today had an element in it ( and a rats nest ) . it was a pommie van .

yes troopy i guess thats were the name comes from i didn't know what it meant as this was really the first time i had any thing to do with a air con.

dibs

Its all about "Latent heat of vaporisation", the heat required to change the state (liquid to a gas, or gas to a liquid) of a substance. If you put your hand on the side of your vans gas bottle when no-one is using gas the surface will all be the same temperature. If you feel the surface when gas is being used, at the liquid level the bottle will feel cold. This is the effect of the liquid turning into a gas. In order to change its state, it takes heat from its surrounding, hence refrigeration. With the air con or fridge we want to keep the gas, and so we need to turn the gas back into a liquid.
By increasing the pressure of the gas via the compressor, the gas is returned to a liquid, but in order for it to change its state, it releases heat, (this is either pumped outside, or used for heating).
And so the cycle goes on again.

Yep so true, that's why they hung a canvas bag of water on the vehicle bumper, the canvas is kept moist, vehicle forward speed aided evaporation, hence the contents were cooled.