18 year old refrigeration -- fix it or ditch it?

[a64pilot]

Last fridge we had was a Sears fridge.
I replaced it at the Wife’s insistence just because it was so old that the exterior had begun to look bad, it was 23 yrs old, and worked perfectly. I had replaced the thermostat and a few ice makers was all.
If you figure it had a 50% duty cycle, then the compressor had over 100,000 hours on it.
What motor driven device do you know of that lasts over 100,000 hours?

[Richard Kollmann]

Originally Posted by a64pilot

Last fridge we had was a Sears fridge.
I replaced it at the Wife’s insistence just because it was so old that the exterior had begun to look bad, it was 23 yrs old, and worked perfectly. I had replaced the thermostat and a few ice makers was all.
If you figure it had a 50% duty cycle, then the compressor had over 100,000 hours on it.
What motor driven device do you know of that lasts over 100,000 hours?

Advising even a technician to replace a small line solder on filter while unit is in the boat without confirming it needs to be changed is like telling him to shoot himself in one foot. There is no risk in following my advice and a big reward if problems with both systems turn out to be old Orings or service fitting cap seals.

[OzePete]

Originally Posted by a64pilot

I’ve had a couple of the electronic sniffers.
They are not nearly as good as soapy water, I even tried using them to find wing leaks on new built aircraft wings by putting some R-134a in the wing, they would alarm, but nearly useless for pinpointing the exact location of a leak.
Soapy water in a squeeze bottle like one used for rinsing out your ear is best, that way you can dribble soapy, but not sudsy water slowly over a fitting. If it has bubbles in it already it’s not as good as pure liquid for finding tiny leaks.
I’m no refrigeration manufacturer, but a “sealed compressor” is honestly about the longest lasting mechanical contrivance I’ve ever been around, they on average last decades.
As long as the refrigerant and oil is pure, often what “gets them” is moisture which turns into an acid.
For that reason, I second Pete’s recommendation of replacing the filter/ drier, and once the leak has been found having a very hard vacuum pulled and held overnight, you cannot pull too deep a vacuum, nor hold one for too long.

Price what two complete replacement systems would cost, you may be surprised.

Good advice re soapy water Pilot. Electronic detectors for R134a only work when you can hear the gas escaping!... ie: useless!

Yes always fit a new proper filter dryer. Sometimes this may mean adding a new flared filter dryer in line rather than replacing if the welded on spun copper strainer is hard to remove.
Any technician here who repairs a leaking system without fitting a new proper filter dryer, is out of a job, period.

Also if replacing O rinds, don't just use any old O ring, they must be R134a compatible.

Cheers OzePete

[Richard Kollmann]

Originally Posted by a64pilot

I’ve had a couple of the electronic sniffers.
They are not nearly as good as soapy water, I even tried using them to find wing leaks on new built aircraft wings by putting some R-134a in the wing, they would alarm, but nearly useless for pinpointing the exact location of a leak.
Soapy water in a squeeze bottle like one used for rinsing out your ear is best, that way you can dribble soapy, but not sudsy water slowly over a fitting. If it has bubbles in it already it’s not as good as pure liquid for finding tiny leaks.
I’m no refrigeration manufacturer, but a “sealed compressor” is honestly about the longest lasting mechanical contrivance I’ve ever been around, they on average last decades.
As long as the refrigerant and oil is pure, often what “gets them” is moisture which turns into an acid.
For that reason, I second Pete’s recommendation of replacing the filter/ drier, and once the leak has been found having a very hard vacuum pulled and held overnight, you cannot pull too deep a vacuum, nor hold one for too long.

Price what two complete replacement systems would cost, you may be surprised.

The advice is out there we will see which one Dockhead takes the less expensive or the guaranteed $1,000 attempted repair and then $3,000 to replace both systems.

[OzePete]

Originally Posted by OzePete

Good advice re soapy water Pilot. Electronic detectors for R134a only work when you can hear the gas escaping!... ie: useless!

Yes always fit a new proper filter dryer. Sometimes this may mean adding a new flared filter dryer in line rather than replacing if the welded on spun copper strainer is hard to remove.
Any technician here who repairs a leaking system without fitting a new proper filter dryer, is out of a job, period.

Also if replacing O rinds, don't just use any old O ring, they must be R134a compatible.

Cheers OzePete

I should have added that if the system leak is from the high side (that is from the compressor discharge, through to the condenser and back to the capillary), then there is a very good chance that the system will not be contaminated. Fingers crossed!

Cheers OzePete

[Dockhead]

Originally Posted by Richard Kollmann

The advice is out there we will see which one Dockhead takes the less expensive or the guaranteed $1,000 attempted repair and then $3,000 to replace both systems.

Yes, thanks to everyone. I think both options are less expensive than this, but nevertheless, it's a tough decision.



A boat like this is packed with different systems which each have a certain service life and which start to give more and more trouble towards the end of that life. So very often it is not worthwhile to try to prolong that life with temporary fixes, especially at the expense of increasing the risk of that system breaking down while you're cruising. So I often incline towards ripping out and replacing, thus keeping the systems newer and on the better side of the reliability vs. age curve. Anyway I try to renew a list of systems and components every year to try to keep the boat in good condition over the long term.



In many cases, stretching the life of old systems does not actually save that much money over the longer term, and especially not if you put value on time spent repairing things, and the disruption, when you're actually cruising. Last summer the boat was used very hard in harsh conditions, sailing all the way to the Arctic and back, 4000 miles, most of it far from any source of spare parts or skilled labor. Nothing broke on this 18 year old boat, except a wind sensor and an electric toilet, neither of which was mission critical. I like to keep it that way, and that takes regular investment into replacing systems, sometimes proactively.



But this one is a tough call -- it sounds like this refrigeration might not be so time limited as other systems. I think I will spend a bit of time myself with soapy water to get a preliminary idea of what I'm dealing with.

[Richard Kollmann]

Originally Posted by OzePete

I should have added that if the system leak is from the high side (that is from the compressor discharge, through to the condenser and back to the capillary), then there is a very good chance that the system will not be contaminated. Fingers crossed!

Cheers OzePete

I agree another reason to proceed with non destructive testing first.

a64 pilot, It sounds like we are dealing here with two systems and very small leaks of maybe one vapor bubble every 5 minutes. The fact this system contains less refrigerant than almost any other system finding a small leak is a challenge, this is why washing soap solution across leak area will not find small leaks. It is also why electronic vacuum sniffer detectors do not work. To make the smallest gas bubble visible it is necessary to break down surface area tension between soap water and metal tubing.

[Q Xopa]

Originally Posted by a64pilot

I’ve had a couple of the electronic sniffers.
They are not nearly as good as soapy water, I even tried using them to find wing leaks on new built aircraft wings by putting some R-134a in the wing, they would alarm, but nearly useless for pinpointing the exact location of a leak.
Soapy water in a squeeze bottle like one used for rinsing out your ear is best, that way you can dribble soapy, but not sudsy water slowly over a fitting. If it has bubbles in it already it’s not as good as pure liquid for finding tiny leaks.
I’m no refrigeration manufacturer, but a “sealed compressor” is honestly about the longest lasting mechanical contrivance I’ve ever been around, they on average last decades.
As long as the refrigerant and oil is pure, often what “gets them” is moisture which turns into an acid.
For that reason, I second Pete’s recommendation of replacing the filter/ drier, and once the leak has been found having a very hard vacuum pulled and held overnight, you cannot pull too deep a vacuum, nor hold one for too long.

Price what two complete replacement systems would cost, you may be surprised.

Yes agreed. Im a big fan of some water and wash up liquid in a spray bottle. Have even used a rag soaked in a handy bucket of soapy water too in a pinch. Spray bottles are cheap and easier because you can spray from a distance hard to get your hand into spaces.
A bit off topic but the soapy water trick can also work for fuel, and other line hard to find, leaks. If you get a bit creative with regulated compressed air.

[RaymondR]

I cut the top off a BD35 years ago to see how well they were made and was very impressed with the build quality.However a lot of the modern stuff is not so robustly built.

[jr_spyder]

I had a super slow leak in my car a/c unit that needed recharging every couple years. The tech put some sort of dye in the fluid, I drove round for week and went back, and he found the leak with a light (I think). Not sure this is relevant to a small refrigeration system, but a thought.

[a64pilot]

A few things.
Richard my little experience with vapor cycle systems is almost all on bigger systems, and there it’s considered Insurence to always change the filter/drier, cause of course what your after is trying your best to remove or at least ensure there is no moisture in the system.
However if the system has never really leaked down, there should be no moisture and as you say installation of a filter/drier may cause more harm than prevent it.

Another thing, my belief of holding a hard vacuum over night comes from trying to remove any moisture that is trapped in the oil. Some say you can’t, but it’s my belief that if a strong enough vacuum is pulled and held long enough, you can remove moisture from the oil. Besides it hurts nothing at all to hold a vacuum longer than min required. Why not leave the pump on overnight?

Lastly, it’s my understanding that the older Danfoss compressors were manufactured in Germany, while the newer Secop ones are Chinese made?
Now it’s true that many Chinese manufactured things are of excellent quality, on average my belief is the older ones may be better made.
I think I’d try to save an old system just for that reason myself.

Lastly Dockhead your right old systems die, just like all most all things do, eventually the whole thing breaks down, this year it’s the evaporator. Next year the condenser etc.
Your call of course whether to fix or replace, but just maybe you would be replacing a German manufactured compressor with a Chinese one, if that means anything.
Of course I could be wrong, maybe they were never made in Germany.
But then I occasionally fly an airplane made in 1946, and we are living in a 32 yr old boat too. Many consider a 10 yr old boat too old.

[Richard Kollmann]

Originally Posted by a64pilot

A few things.
Richard my little experience with vapor cycle systems is almost all on bigger systems, and there it’s considered Insurence to always change the filter/drier, cause of course what your after is trying your best to remove or at least ensure there is no moisture in the system.
However if the system has never really leaked down, there should be no moisture and as you say installation of a filter/drier may cause more harm than prevent it.

Another thing, my belief of holding a hard vacuum over night comes from trying to remove any moisture that is trapped in the oil. Some say you can’t, but it’s my belief that if a strong enough vacuum is pulled and held long enough, you can remove moisture from the oil. Besides it hurts nothing at all to hold a vacuum longer than min required. Why not leave the pump on overnight?

Lastly, it’s my understanding that the older Danfoss compressors were manufactured in Germany, while the newer Secop ones are Chinese made?
Now it’s true that many Chinese manufactured things are of excellent quality, on average my belief is the older ones may be better made.
I think I’d try to save an old system just for that reason myself.

Lastly Dockhead your right old systems die, just like all most all things do, eventually the whole thing breaks down, this year it’s the evaporator. Next year the condenser etc.
Your call of course whether to fix or replace, but just maybe you would be replacing a German manufactured compressor with a Chinese one, if that means anything.
Of course I could be wrong, maybe they were never made in Germany.
But then I occasionally fly an airplane made in 1946, and we are living in a 32 yr old boat too. Many consider a 10 yr old boat too old.

I do take a different approach to troubleshooting any refrigeration problem by first locating and confirming what need to be done to correct it eliminating the shotgun approach saving time and money. Once the system is operational again in the next six months I follow up with what might be good insurance to prevent future problems such as Dehydration to 200 microns for 4 hours and adding a new replaceable correct size filter dryer. I deal with boaters in remote areas of the world weekly and have learned the hard way that technical expertise is not available in most areas to replace solder on small line filters.

Even when a new filter is justified the old one can be left alone and a new one installed in liquid line some where that is excess able using refrigerant heave cast brass refrigerant flare nuts. If new filter is larger than the present one It should be mounted vertical with flow arrow pointing down to reduce the possible vapor that will occur in the larger filter from interring capillary tube. One reason for the extra long cap tube is to insure final condensing happens before interring evaporator. The phase change in large filter may more than cap tube is designed to handle.

If you are concerned about Chinese made compressors that is something we all have to live with as it looks like all 12/24 volt compressor manufactures are going to be products of China. Your boat's compressor was probably originally made in Spain, do you know where they are made now?, I don't I can not even find the manufacturers application performance figures on your compressor let alone where they are now made.

[taylormobile]

I have 30 years on my Danfoss. I have heard that the life span of a Danfoss is unknown because units like mine are still running. I did have to replace the electronic controller 3 years ago.

[Cpt Mark]

I just went through this decision with my 25 year old Grunert system. Mine used R-12 which was a large reason why I decided to not try and find the leak(s).

Looking elsewhere on CF I saw a number of people using dorm size refers instead. $200. They are very energy efficient etc. I didn't want a door opening refer on a moving sailboat at sea so after a lot of research I chose the Snomaster chest type Refer/freezer. Comes with a 5 year warranty.

Now to install it in the old box which after removing the counter top, half the fiberglass box and foam will fit nicely has been a week into it so far. Mostly because I didn't want to destroy the counter top in the process. The laminate top was peeled off and a new one will be installed along with some additional new items now that I have awesome access.

The Snomaster is the largest one they make and barely fits in the old box but because it is insulated and has 2 compartments will hold a lot less than what I previously had. I wonder now if maybe I could have just bought a small chest freezer and adjusted the temperature for refer temp of 38? This would be even less money but then wouldn't have had 2 compartments that can be either freezer or refer.

It's a boat, decisions decisions .

[s/v Jedi]

The Danfoss compressors are extremely reliable but after 15 years, mine make a very different sound. We have three BD50 compressors from 2004 and a couple of years ago I swapped the one that ran most with the one that almost never runs and the difference was significant. Much quieter as well.

That doesn't mean that the other one won't run for another 50 years... I would believe that as well

Not so for condensers, evaporators and especially not for keel coolers. They all go bad. That said, my spare evaporator and condenser are still new in their boxes after 15 years