Recharging your A/C: is it necessary?

I've been reading online and I am very confused. Some say you should never recharge your A/C system if everything is operating properly. While others say adding pure 134a refrigerant/coolant will help with your cooling. My Mazda dealer says one shouldn't need to recharge the A/C either.

In particular, my 2005 Mazda3's A/C isn't quite as cool as it used to be, partly because the temperature outside these days is much warmer too. Additionally, in 2006 my A/C was checked at the dealer, discharged and new coolant with a dye was added under warranty for another issue. My understanding is that with the dye or lubricants, the A/C won't run as cool as one with pure coolant.

I'm in Canada and by law, only a licensed A/C technician can work on an A/C unit, that's why we don't have canisters and DIY A/C recharging system. In Asia, where temperature extremes are normal, people get their A/C unit serviced and flushed too at the dealer.

I am not a handy around my car and I wouldn't want to mess around with the A/C even though I can get my hands on DYI kits.

Can someone shed some clarity whether or not recharging the A/C is necessary?

You have to have the lubricants for the system to function. They don't hinder performance. Dye doesn't either.

In theory you should never have to recharge the system. It is a sealed system, so if everything is running properly it should be fine.

Leaks are the number one failure mode of a/c systems- the only way to know if your system needs refrigerant is to extract and weigh what is in your system. If it is not to spec, then you have a leak and it need to be fixed, You would not let a tire continue to leak would you? Does putting air in a tire fix it? I say not....

Though many car owners think they need to recharge or "top off" their air-conditioning system with refrigerant on a regular or annual basis, that's not the case. An AC system is a closed system, and if there are no problems, coolant is not consumed by the vehicle, nor does it escape. Unless your auto's AC is in need of repair, there is no need to "top off" the system. If the air conditioning stops working but the fan continues to blow warm air, a leak in a hose, connector or other part of the system is probably the culprit.

A bit of semantics here, but antifreeze/coolant is what goes in the car's cooling system to keep the engine from overheating during operation and used by most vehicles to provide cabin heat for the passengers. Refrigerant is what's in the A/C system that is used to remove moisture from the air and cool the passenger compartment.

If you go to a shop and ask to have the "coolant flushed" or the "coolant topped off" you will likely be disappointed in what you receive, unless the shop is good about asking clarifying questions.

-Rod