Page 7

AC Systems

Air Conditioning units use fluid compression for dealing with heat, except to cool off instead of heat up.

The compressor of an AC places coolant under high pressure, where coolant is a fluid used in the AC because of how it responds to temperature.

This causes the coolant to super-heat, as all of that pressure converts the kinetic energy in the particles of the coolant into heat.

The AC then cools it off at this high pressure by blowing air from outside the space over the pipes of coolant, removing a lot of the heat.

Next, the expansion joint of the AC expands it to normal size to super-cool the fluid. The AC blows air from inside the space being cooled over pipes filled with this super-cooled fluid, which then is used to cool off the air it blows into your house! You can see this in action at the following link:
http://www.swtc.edu/ag_power/air_conditioning/animation/intro.htm

This can also be reversed to heat up instead of cool off your house.

If you physically expand the coolant first, it becomes cold because it loses pressure (Remember PV=nRT). When the very cold expanded coolant comes into contact with the warmer outside air, it heats up.

When the coolant is then compressed, it heats up. Then this coolant is used to heat up the air inside your house!

On to page 8!