Mr. Freeze - The Auto Air Conditioning Good Guy!

Mr. Freeze - The Auto Air Conditioning Good Guy!

He may have been hellbent on destroying that pesky Batman … but when it gets to summer in the South, especially if you have to commute work and try to arrive looking fresh, you'd be glad to have him in your life! Mr. Freeze would have been infused with some sort of refrigerant -- just like your automotive air conditioning system is. However, your car was most likely not involved in a cryogenics acicident while trying to treat its sick wife! So what is the science of Mr Freeze -- how do refrigerants actually work in your AC system to cool you down?

A refrigerant gas is placed in a sealed system of pipes or tubes, and pressurized with a compressor. The compressor is one of the most common failure points of your AC parts system. The compressor needs to be able to create enough pressure to turn the refrigerant gas into a liquid.

The refrigerant is almost always mixed with a small amount of oil, which helps lubricate the system. There are very specialized oils used in auto air conditioning systems. As the refrigerant is pressurized, it becomes very hot, just as a bike tire does when you pump it up (increasing its pressure). The liquid passes through an expansion valve into a chamber where the pressure is much lower, allowing it to return to a gaseous state.

In returning to a gas, the refrigerant absorbs heat from the air around it. A fan then blows the cooled air into the car, and another fan generally blows air from the hot part of the pipes away from both the car interior and the engine (ideally).

There are quite a few possible failure points in this system. If the compressor doesn't work hard enough to completely condense the refrigerant into a liquid, the air won’t be as cold as it could be. If the expansion valve is leaky, you may get cold air further back in the system. Many auto air conditioning systems also incorporate elements like accumulators, driers, evaporators and condensers, which all have the potential to leave you sweaty and dizzy after the commute to work, if they aren't operating properly.

There is a long list of refrigerant substances used by DuPont, which assigns an R-number to each chemical. The list runs from R10 up to R1250 (with quite a few gaps), and also includes letter designations after some of the names. is currently the most commonly used chemical in automotive air conditioning systems.