Refrigeration -- End of Life?

[Dockhead]

Originally Posted by Seaworthy Lass

Do you have any room to fit a small portable unit somewhere? eg Lazarette? If your system fails this summer it at least gives you a back up. It may then allow you to continue to enjoy cruising rather than needing to return to port and suffering long delays while a new system is installed.

I have two completely separate reefer systems (which is good systems architecture). So if one fails completely, then I've got the other one. I'm not really concerned about it.


First of all, they've lasted this long and the leak is not apparently worse than it's been for years. I managed to get enough gas in both systems that they are now both working well. There is some risk of sudden death but I think it's probably not likely.


Second, I will not be doing any remote adventure cruising this year where the reefers would be mission critical -- just knocking around the Baltic, perhaps up the Norwegian coast a bit. Never so far away from a port that I couldn't source a few bags of ice every few days in the absolute worst case of double failure.


Then I'll haul out for a month in Cowes next spring and that would be the time to do the replacement.

[s/v Jedi]

I concur with Seaworthy. Create a place for a portable unit and get it sooner rather than later. Everyone who takes the step wishes they had done it sooner.

Also, about two boxes and the slow leaks. I had three boxes and slow leaks. The slow leaks are easy to fix: new O rings in the couplings, new evaporators and new condensers. That still leaves the more serious faults which are still hidden to you: box insulation. I can all but guarantee that each of your boxes has wet insulation which killed the R-value. I recommend you measure the duty cycle of each box before making any decisions because this is by far the most serious problem with the most difficult repair.

Edit: unless the duty cycle reveals a perfect insulation, you can next measure box insulation by measuring the time it takes to melt a block of ice. The method is well described by Nigel Calder.

[Dockhead]

Originally Posted by s/v Jedi

I concur with Seaworthy. Create a place for a portable unit and get it sooner rather than later. Everyone who takes the step wishes they had done it sooner.

Also, about two boxes and the slow leaks. I had three boxes and slow leaks. The slow leaks are easy to fix: new O rings in the couplings, new evaporators and new condensers. That still leaves the more serious faults which are still hidden to you: box insulation. I can all but guarantee that each of your boxes has wet insulation which killed the R-value. I recommend you measure the duty cycle of each box before making any decisions because this is by far the most serious problem with the most difficult repair.

Edit: unless the duty cycle reveals a perfect insulation, you can next measure box insulation by measuring the time it takes to melt a block of ice. The method is well described by Nigel Calder.

Thanks; that's a good tip about the box insulation. I'll check that.


I would love to have self-contained portables but there is no way I'm ripping my beautiful U-shaped galley up. I am quite happy with the existing system and would be perfectly happy renewing it. If I can save some power by fixing wet insulation that will be a nice bonus, but the power consumption at the moment is not a problem. I have an electric-intensive boat which I run off a heavy duty low speed generator, so power consumption of refrigeration is not one of my problems. And anyway, the Isotherm SP system is extremely efficient in the icy cold water I sail in. If I were in the tropics and very warm water this might all be a completely different ballgame, but I'm not.

[s/v Jedi]

Originally Posted by Dockhead

Thanks; that's a good tip about the box insulation. I'll check that.


I would love to have self-contained portables but there is no way I'm ripping my beautiful U-shaped galley up. I am quite happy with the existing system and would be perfectly happy renewing it. If I can save some power by fixing wet insulation that will be a nice bonus, but the power consumption at the moment is not a problem. I have an electric-intensive boat which I run off a heavy duty low speed generator, so power consumption of refrigeration is not one of my problems. And anyway, the Isotherm SP system is extremely efficient in the icy cold water I sail in. If I were in the tropics and very warm water this might all be a completely different ballgame, but I'm not.

Fixing wet insulation isn’t something to take lightly... I guess one has to do it once before understanding what is involved with that. What Seaworthy and I recommend isn’t ripping up your galley: it’s finding an additional spot for a portable box.

Also, many brands sell drawer-style refrigerator units that can be installed in your galley as is. In the US during Black Friday etc. these can be had for reasonable prices and I would prefer those over the task of replacing insulation. You really need to get a duty cycle of 50% or better not just to be more energy efficient but because that’s what refrigeration units are designed for. It would be equivalent to a compressor that is too small for a box etc.

[Anders]

Originally Posted by s/v Jedi

Here’s a couple of pictures... front access, just make slides to hold the units. I have a third unit in the pantry

How do you attach the slides to the units?

[s/v Jedi]

Originally Posted by Anders

How do you attach the slides to the units?

I built trays that hold them.

[wsmurdoch]

We have a R-12 hermetic system with a permanently installed low pressure gauge. Four or five years ago the system quit working. The gauge showed 0 psig with the system shut down... obviously it had leaked flat. I called a highly recommended tech who over the phone said, "Pull it all out and put in new. There is no point in trying to fix it. R-12 is hard to get and expensive, and the system is old." Richard Kollmann said, "Pressurize the system and find the leak before you do anything." I went looking for the leak with Joy detergent, water, and a cheap paint brush. The leak was a service cap with a dried out rubber gasket; a $0.50 item. I whined about the difficulty in getting R-12 around the dock, and the next morning I had three 12 oz cans; all gifts from other people's garage shelves. I replaced the filter/dryer, vacuumed the system, charged R-12 until the frost got back almost to the compressor, then put the remainder of that can of R-12 in a lecture bottle for safe keeping. The other two cans are now on my garage shelf and the fridge is still working.

As Joe Cocker said, "I get by with a little help from my friends."

[RaymondR]

If you have two of them, don't mind doing the work, and have an aversion to wasting equipment which might yet have years of service life remaining, it appears to make sense to replace one of them with new and keep the old as spares and get another 5-10 years out of the old ones. This way you will have staggered the replacement and covered the reliability, waste, availability issues.