A/C Aerosol Can replenish systems... do they work?

[Meractik]

I just moved to the desert and I am curious, those of you familiar with vehicle refrigeration systems such as the ones used for A/C do these replenish systems you can buy in wal-mart auto center that come with gauges and claim you just hookup to the A/C Nipple thingy in the front of your vehicle and recharge actually work?

IF they do work, is it safe to use? is it damaging? just a "temp" fix?

I am also curious as to whether the use of them may harm the longevity of the A/C system....

I live in the desert and always crank my A/C in my car and have noticed its ability to cool has diminished greatly, is this something I should see an A/C specialist about to replenish the coolant within the system or would a quarterly purchase of one of these A/C self-boost system like things be a better option?

something like acprocold (dot) com is something I see on TV a lot with a real cheesy commercial....

 

[phucheneh]

It's not an aerosol. It's refrigerant. If your car is low on refrigerant...yeah, of course it works. Assuming you're able to meter in the correct amount.

I laugh my ass off when I see people paying like $30+ for a 12-18oz can of refrigerant, though. I get 12oz cans of house brand for like five bucks. There is no difference. I strongly recommend buying a ~$50 set of manifold gauges instead of paying a silly amount for a can of refrigerant because they stuck a $1 gauge on it.

 

[Meractik]

well good to know, so technically one could buy a simple gauge to figure whether they're low on refrigerant 1st? (by hooking said gauge to vehicle refrigerant and reading recommended level via vehicle specification) ?

similar to checking tire pressure?

 

[phucheneh]

There's more to it than that. If the system is almost empty, yeah, you'll know. But if a system takes, say, two pounds, and it currently has one pound in it, it can be hard to tell that it's that low with gauges. You need an understanding of how the system works, and take lots of factors into consideration.

Using that example, you may see 30psi on the low side and 180psi on the high side. Doubling the amount of refrigerant to reach capacity may yield, say, 35/220. Overcharging by just a few ounces may up that to 45/300. It's very hard to say what numbers you will end up getting, since, in addition to wide variations based on ambient conditions, different systems just act...differently.

The most basic advice I would give, is charge up to 30-35psi or so while monitoring the vent temps (can also just feel the low side line near the firewall). Once it starts getting cold, meter your refrigerant very slowly, turning off the flow frequently to check your gauges, stopping when the system starts to have a hard time pulling down into the 35-40psi region. This is assuming maybe a 90* day.

Slightly undercharged usually works better than slightly overcharged.

A good initial check would be to see if the compressor is coming on. Past that, just feel the lines. The high side before the condenser should be 'oh shit' hot (be careful). The low side before the evaporator should feel pretty close to an ice cube. If you have pretty hot high side but the low is only room temperature, you're probably low on refrigerant. Or your cooling fan isn't working (an electric fan should be running any time the compressor is on).

 

[Meractik]

Okay cool, thanks for those troubleshooting tips, ill definitely take them into account when trying to identify the possible issue prior to the system completely kicking the can and not working at all.