Cruisair Replacement question

[Boatsb]

Thumbs on phone make numbers tough but you get the idea. Also some new systems require 250 or lower.

If the lines are re used and cleaned out there's a good 2 or 3 hours to flush with nitrogen then evac properly. I've never seen a 2 hour swap that worked long.

Also oil in the compressor needs to be clean and dry, fittings need to be tight and a pressure test with nitrogen is best before pulling a vacuum. All takes time and adds to the cost of doing it right.

No one even discussed changing refrigerant which requires a good cleaning with a specialized chemical product.

 

[Reefgeorge]

The scope of an AC retrofit has a very wide range of time involved and to the extent that someone is asking for advice here we should be giving them an appreciation for the range of possibilities and the time involved including a system upgrade that can go a lot faster than a really complicated job. A well trained and well equipped professional can actually do the system evacuation much faster than an inexperienced person with low end equipment. Sophisticated high end pumps with 3/8" braided stainless lines, core removers, fancy vacuum manifolds etc can drop the time by 70%. Nitrogen sweeps and triple evacuations speed up the evacuation of a heavily contaminated system. System flushing may not be necessary if the compressor didn't puke including line flushing if the oils are the same or compatible. If the compressor is new it comes with new oil that is dry in a nitrogen charged state. Of course the converse of these can be true and some jobs need a lot more conversion and clean up work. Part of why you would pay a top notch $100/hour guy is because with all the training, truck full of gear and experience they can do a top notch job faster and better than most. I have evacuated many systems in less than an hour that are still working going on ten years. Some take much longer but time has nothing to do with it. It's getting under 500 microns, blanking off the vacuum pump and seeing if it holds for 15 minutes or longer. If you pressure tested first with nitrogen then residual moisture is indicated when the vacuum stalls at around 1500 on the way down. An experienced guy knows these things, can see if the system is dry, get to 500 and stop. If you see evidence of high moisture content then you start a triple nitrogen sweep which shortens the time not lengthen it.

My point is to inform the OP and anyone else looking for advice here so that they can know a good AC guy when they are meeting one, ask intelligent questions, and get fair treatment. A really messed up system can be a complicated and lengthy job indeed but many of them do not need all of the possible steps and a really good AC guy makes much quicker work of a quality job.

George

 

[dave1985]

An update to the original question...
I was referred to a very qualified A/C tech/dealer. He confirmed the compressor was bad but everything else was in excellent shape. He could have upsold me but he just replaced the compressor. The system is running great and it was a very reasonable bill. Talent and experience are a good thing.

 

[Reefgeorge]

Glad you got taken care of and like the outcome. I went your route on both of my systems when they failed. Worked out great.

George