Refrigerant.

Refrigerant is the fluid that carries heat out of your house. It boils into a gas in the indoor coil while absorbing heat, gets compressed into a hot high pressure gas, gives that heat up in the outdoor coil, and turns back into a liquid to start again.

“Freon” is a brand name that became a generic word. What is actually in a Valley system is usually R-410A, sometimes R-22 in older equipment, and increasingly R-454B in new installs.

The one thing worth understanding

A sealed system does not consume refrigerant. There is no reservoir that empties and no filter that uses it up. If a system is low, it leaked.

That matters because “we topped it off” is not a repair. It is a payment for gas that will leave again through the same hole, on roughly the same schedule. The leak is the job. Topping off without finding it means paying for the charge twice, and a system running low in the meantime risks the compressor.

Low charge also freezes coils, because low pressure means a colder coil than the design intended.

R-22 and old systems

R-22 was phased out of production and import, which made it expensive. If an older system has an R-22 leak, the arithmetic often stops favouring the repair, and that is a legitimate conversation rather than a sales tactic. It is still a conversation worth having with somebody who is not also selling the replacement.

What EPA 608 means

Handling refrigerant legally requires EPA Section 608 certification. That is a federal certification about refrigerant handling. It is not a contractor licence, and it does not permit permit-required work. Both things are true at once and the site says so plainly.