HVAC gauges

[tonytrakovich]

I am thinking about purchasing a set of gauges so I can top off my own cruisair units. Does any one else do this? What is a good brand / type of gauge? Cost? Can you buy the proper refrigerant? Of course I will read up and learn how to do the maintenance so I don't ruin anything.

[Boatsb]

You top them off after fixing the leak. Therefore if you can't fix it topping them off is just deferred maintenance.

HVAC systems are changing. New gasses are blends and can't be topped off. Old gasses like r22 are becoming expensive and hard to get.

You may find it's not a good time to learn the basics when there's more to it than just filling a system with gas you can't legally buy or use.

[krush]

To legally buy r22 in the usa you need to be certified. This means taking a test (which can be done at many HVAC suppliers). To pass the test, you need to understand and know the theory and some rules. If you are here asking about gauges and refrigerant, you will not past the test without much learning.

Newer units use 410a, which can be bought by anybody (just 134a).....for now. I think this is set to change.

HVAC systems are changing. New gasses are blends and can't be topped off. Old gasses like r22 are becoming expensive and hard to get.

Some blends they say don't top off. Is this just by the book and not practical in the real world??? Potentially.

410a can be topped off.

[Boatsb]

Blends do not leak all components equally. The smaller the molecule the faster it's part can be depleted. If a system is leaking down the remaining refrigerant may not be as efficient as it's ratios are not correct.

[racclarkson@gmail.com]

To legally buy r22 in the usa you need to be certified. This means taking a test (which can be done at many HVAC suppliers). To pass the test, you need to understand and know the theory and some rules. If you are here asking about gauges and refrigerant, you will not past the test without much learning.

I seem to have friends who have gauges that might they want to sell. They always seem call the pro's after they've had a go at AC work.

[Reefgeorge]

A basic Yellow Jacket gauge set works fine, however:

You can't buy most refrigerants without an EPA 608 certification. You take a proctered test at a certified facility. There are four sections related to different types of equipment. You have to pass the general section plus the sections related to your work. Pass all sections and you get a universal certification. You can study for this test with material that you can buy online. Passing this test does not make you good at doing HVAC work but it does sensitize you to good environmental practices and gets you up to speed on refrigerant technology. If you were to get certified keep in mind that many mistakes can be made without proper knowledge. Just adding gas because the low side pressure is low can get you into trouble. Also, once you hook up to a set of service ports you are required to have all of the other equipment to properly service a system (vacuum pumps, reclaim machines, reclaim containers, etc.). Lastly, releasing refrigerant into the atmosphere carries a hefty fine ($28K) and the potential for prison time. The first prison term was given for this in 2014. Point being that it's not a casual DIY project unless you make a commitment.

All that said, if you are technical and a good problem solver, it is doable.

On the issue of blended refrigerants, some fractionate as they leak and the mix can get out of whack and many now require that you charge as a liquid which can trash a compresser from slugging if you are not careful. That said, some of them can be topped off as a liquid and not preturb the system balance to any significant degree. Again, a set of gauges is not enough knowledge.

George

[tonytrakovich]

Thank you George for being the one to answer my question. I have been reading your AC posts lately and you seem to be the resident expert on this. You also have a nice way of explaining things so people can make decisions on the tasks they want to try themselves. Whereas Ill admit that I dont know much about the refrigerant side of AC systems, I would not do anything that has a chance of hurting my equipment or personnel. That being said, I am a better than average DIYer, I can read, and I have the ability to learn. On one of my units, I had a certified AC guy tell me I needed a new compressor. After doing my own troubleshooting I found a bad thermal OL switch on the compressor. I have 7 split systems. All running R22. All evaporators except one are pretty old. I have an old FS30 unit that is original 1989. Also have 5 RX units that were converted to R22. I find it hard to believe that these split systems dont need to be topped off over time. Even if there are no detectable leaks.