Does anone know of any mobile fridge "re-gassers"?

wingdiver said:
So can any fridge engineer charge/top up a R134a filled system? <snip>
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Yes, your systems work in exactly the same was as any other compressor fridges/freezers and automotive air-con systems. Basically, the compressor pumps the refrigerant into the condenser (the bit up the back of your fridge that gets hot, it gets hot because it's full of compressed refrigerant). Where the condenser pipework joins the evaporator (the bit in the fridge that gets cold, often the actual structure of the "freezer" compartment) the pipe meets a restriction. The restriction is often an inline filter. This restriction and the pumping of the compressor maintains a reasonably constant pressure in the condenser. From the filter (if fitted) the refrigerant passes through a capillary tube and exits the tube into the evaporator. In doing so the refrigerant de-compresses. Compression causes heat, therefore de-compression has the opposite effect, the evaporator gets cold.

A very simple system really, but it does need to be very clean and dry inside. The capillary tube internal diameter is so tiny it's very easily blocked, if it gets blocked, the compressor can be powerful enough to force the blockage in so hard that it's impossible to clear. The tiniest amount of moisture in the system can also result in blockages caused by ice, as the moisture freezes when it enters the evaporator.

The refrigerant also carries with it an oil, this oil lubricates the compressor. If a system develops a leak, some of this oil will escape and will need topping up. Air con systems have pressure sensing switches fitted to prevents the compressor running if the system is low on refrigerant, no refrigerant flow equals no oil circulation, equals a dead compressor.

R12 used to last the life of a fridge, but R134a needs periodic servicing. The R134a molecules are so small that they can slowly get by the seals, so your systems slowly empty, without having a leak, as such. The slow escape of R134a molecules doesn't allow the oil to escape, whereas a "proper" leak would.

Basic refrigeration servicing is kids stuff. With typical domestic and aircon systesm, you connect the service equipment to the system and run a vacuum pump for about 40 minutes, this removes any loose particles in the system and to remove any air, thus removing the moisture. You then leave it to stand for another 40 minutes, if the system maintains it's vacuum, it doesn't have a leak. You then fill the system with a measured amount of refrigerant, by weight. At no time between putting the system under vacuum and the re-filling is the system opened to atmosphere, as this would let moisture back in. Job done.

So in short, anyone who can service any R134a system can service all R134a systems. But with respect to Bendyone, you should be able to see from the above that a bottle of Halfords R134a might not be the best solution and could end up costing you a lot of money.

Around here, air con servicing is around £40 if you take your car to the garage, so expect a little more for a call out.

One caveat, some servicing systems are too bulky to get onto a boat.
 
If a Danfoss type fridge loses its gas there's usually an underlying reason I would have thought. Re-gassing might only be a temporary solution.

Someone like Will Hayward would be able to assess if there was a problem that needed fixing.
 
Ianqv said:
Doh!!! sorry.... yet another senior moment!! here it is:
http://jeanneau.proboards.com/index.cgi?board=general&action=display&thread=1623
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Thanks Ian. Mr sailbleau is a good example of a little knowledge being dangerous, he seem very fond of his bottle of R134a :D He couldn't even work out how to get the gas into the system, but the two pics he posted clearly show the service port lol Just above and to the right of centre, you can see a short length of copper tube, with a black fitting on the end :)

The link at the bottom of the thread gives some useful info too. http://www.cruisersforum.com/forums/f115/bizarre-frigoboat-behaviour-54872.html
 
wingdiver said:
I have replaced the compressor and evapoator box on the big one and had it gassed by a marine fridge specialist. It doesn't really work as well as it should and probably needs redoing as I don't believe it is cooling throughout the evaporator plate.
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It sounds very much like this one doesn't have enough refrigerant. If it's never worked properly since being done, the guy should really come back and put his work right. If it worked OK for a while, then i'd say you have a leak.

The other has been regassed and 'vacuumed' but is no longer working so I assume it either has a leak in the system or the compressor needs replacing.
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Vaccuumed, then re-charged. The guy doing the job should have checked for leaks when he did it, by leaving it under under vacuum for a time. Hard to hazard a guess what's wrong with this one. You need to get someone to check the other one, get him to look at this whilst he's there.
 
Quick update.
As mentioned before, one fridge had stopped working and the other was dropping away in performance. :mad:
Saw a guy in his van, advertising air con and refridgeration work, at the marina last week and had a word - his name is Paul and he is based at Ipswich Haven.
He arranged to come over at the weekend (on Saturday) to check the fridges.
The main one which was working after a fashion was found to be low on pressure when tested so it was charged up, left to run for quite a while and the temperature inside the freezer box and in the main fridge checked. Gas topped up as temperature dropped until constant temp. Then left for a while to check no loss of pressure due to leaks. Then leak tested joins as a double check. All good. :D
The smaller fridge had virtually no pressure. Topped up and checked as with the main one above. All good. :D
By yesterday, I had to turn down the setting in the small fridge as the bottle of water in there had frozen. Worried about that happening to the beer!!! :cool:
Excellent job.
Thanks for the info provided on here as part of the solution.
 
wingdiver said:
Quick update.
As mentioned before, one fridge had stopped working and the other was dropping away in performance. :mad:
Saw a guy in his van, advertising air con and refridgeration work, at the marina last week and had a word - his name is Paul and he is based at Ipswich Haven.
He arranged to come over at the weekend (on Saturday) to check the fridges.
The main one which was working after a fashion was found to be low on pressure when tested so it was charged up, left to run for quite a while and the temperature inside the freezer box and in the main fridge checked. Gas topped up as temperature dropped until constant temp. Then left for a while to check no loss of pressure due to leaks. Then leak tested joins as a double check. All good. :D
The smaller fridge had virtually no pressure. Topped up and checked as with the main one above. All good. :D
By yesterday, I had to turn down the setting in the small fridge as the bottle of water in there had frozen. Worried about that happening to the beer!!! :cool:
Excellent job.
Thanks for the info provided on here as part of the solution.
Click to expand...

Do you have the contact details of this guy?

Many thanks

Ian
 
wingdiver said:
Quick update.
As mentioned before, one fridge had stopped working and the other was dropping away in performance. :mad:
Saw a guy in his van, advertising air con and refridgeration work, at the marina last week and had a word - his name is Paul and he is based at Ipswich Haven.
He arranged to come over at the weekend (on Saturday) to check the fridges.
The main one which was working after a fashion was found to be low on pressure when tested so it was charged up, left to run for quite a while and the temperature inside the freezer box and in the main fridge checked. Gas topped up as temperature dropped until constant temp. Then left for a while to check no loss of pressure due to leaks. Then leak tested joins as a double check. All good. :D
The smaller fridge had virtually no pressure. Topped up and checked as with the main one above. All good. :D
By yesterday, I had to turn down the setting in the small fridge as the bottle of water in there had frozen. Worried about that happening to the beer!!! :cool:
Excellent job.
Thanks for the info provided on here as part of the solution.
Click to expand...

Good stuff, glad to hear it all got sorted.
 
Paul's excellent description of servicing R134 systems earlier in the thread misses out one crucial difference between a cars aircon system and domestic or marine fridges. The compressor on a car system is driven mechanically off the engine, which means it has a running seal where the shaft goes into the compressor. Most domestic or marine electrically driven compressors have a canned motor, meaning that only static wires have to penetrate the compressor which can be much more effectively sealed.

As a result car systems tend to lose refrgerant, albeit slowly, through the running seal, particularly if it is R134. However, a well built domestic or marine system should have virtually zero leakage, even with the relatively small (but much bigger than hydrogen) R134 molecules. We are therefore accustomed to having our car aircon systems regassed from time to time, but ask yourself when you last had to have your fridge or freezer at home regassed. your boat should be no different.

If it does need doing, you should first be looking for the leak and fixing it - otherwise you will soon need to regas again!

When it does need doing, like others, I'm a great fan of Will Hayward who is also a whizz on marine gas systems. He lives in Saxmundham, so is local to the East Coast, but works on boats all over the world. His work is first class, his prices reasonable and he's a great guy. To find him just Google Gasboat.

Peter Wright
Wild Thyme
Moody 425
 
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