Warm AC

[DerE85Fahrer]

I noticed a while back that my AC is not blowing cold. Its not hot or especially warm, its just slightly cooler than ambient. I'm not entirely sure how long this has been an issue since I don't often drive the car when the weather is not nice and I hardly ever use heat or AC. However, temperatures are now up in the high 90's and I'd like to be able to enjoy the car a little more. The system has never been recharged as far as I know, so I'm hoping it just needs refrigerant. The compressor seems to be working, its just not particularly effective at the moment. I noticed that Home Depot has cans of refrigerant, but they had a couple different kinds, and I have not been able to find any information about what kind our cars take. Can anyone point me in the right direction as far as what kind of refrigerant to use? Hopefully this doesn't end up being a more serious issue that requires a shop to work on it.

[pungo]

It takes R134a. I assume you have a set of mechanics a/c gauges to add the refrigerant using a chart listing ambient temp and %humidity to know what value range the high/low gauges should be when it's properly charged? Even then, it won't be as accurate as evacuating the system and holding a vacuum, then filling the exact amount on the sticker by weighting it on a scale.

[DerE85Fahrer]

I was planning on purchasing a set of gauges for this job. Ideally I would have the system purged and refilled, but there are no reputable shops close to me, so I'd be stuck taking it to the dealer which is an hour and a half away. I also need to get my top motor replaced, so I'll probably have the AC system gone through when I take the car in for that, but I'm hoping I can get it working before then because I don't plan to get the top looked at until the fall.