Frigoboat troubles,again and again...

[kamikater]

hi there,
we have a 10year old frigoboat keelcooler system on board wich came with the boat.of course it gives us troubles...sometimes cools,sometimes dont...uses too much electricity,evaporator sometimes frosted,mostly wet.
tapping evaporator lines etc.

from my research in the forums (kollman,shocktherapy,various users)
i pretty much know its either debris or frozen water in the evaporator.

we are on the way to the south pacific.
i thought of replacing the evaporator and getting rid of the quick connects in panama,since i can order parts there pretty easy.i would replace the evaporator and all new copper lines,plus two dryer/filters.the evaporator plates they sell now seems
to have an additional filter next to the plate.

i would install everything and have someone with a brazing torch come over to to the rest.
charging the system i can do by myself.

am i doing the right thing?
anything i've missed?

just want to have peace of mind for a couple of years (i hope)

chris

[a64pilot]

I think the additional filter / drier will fix many issues they seem to have, getting rid of the quick disconnects, I understand why, but then maintenance gets harder, maybe instead get the good ones, the ones that form a metal to metal seal and don’t rely on o-rings.
I believe Rich Boren (Cool Blue) can tell you the name of them and may even sell them, can’t hurt to ask.

Of course you need to pull a hard vacuum, in my opinion overnight and let it sit to see if it leaks overnight, and I believe if you braze you may need to fill the system with nitrogen first?

[kamikater]

good call,thanks!


ps: if i would have the moneys i would go for cool blue rightnow
maybe on the next boat.....

[CarlF]

I’ve had three Frigoboat keel coolers on three boats over close to 20 years. The first two had occasional troubles from blockages. The new one with the filter/dryer has been completely trouble free for over five years. Efficient, quiet, really perfect. Maybe I just got lucky but I think a filter/dryer with a proper evacuation (repeat the evacuation several times with nitrogen purges) will probably fix it.

As to the disconnects, I have dutifully replaced the large O ring at five years as in the instructions and they’ve been fine. Were your O rings replaced on schedule?

To put in the filter/dryer you’ll need to evacuate the system so it will be easy to replace both the large o-ring and the small o-rings in the process. Cutting and brazing in a home brew solution just seems risky when the O-rings are reliable if replaced on schedule.

Or just decide that a 10 years life is not great but not bad for an OEM install and get a new system for the South Pacific.

http://www.veco-na.com/images/Cap_Tu...th_Diagram.pdf

[kamikater]

i don't know if i got you right,
but if i would keep the old evaporator and put a new filter/dryer in at the plate,
that would also include brazing.

if i change the evaporator,the copperlines and the quick connects i can be shure theres no possible new source of leaks/debris
ps: copperlines were also leaking before and fixed with jb weld

i don't see any benefit of quick connects....if something fails i have to braze anyways...or am i completly wrong?

[Budawang]

I have had a similar issue with our K 35 F. Had ice build up in tubes so I installed a drier. That fixed the icing problem but now it looks like we have a slow refrigerant leak probably due to poor welding of drier. My tubes also make a noisy rattle at times.

[Northbound44]

On my previous boat I had two fridge, both had the same size and same insulation. The first one using a Adler Barbour system and the second an air cooled Frigoboat system. Both systems were identical , including Danfoss DB50 compressor and same size evaporators.
The only difference between them was the dryer/filter the Adler Barbour was equipped with. At the beginning of the season or sometime when I tried increasing the speed of the compressor with the controller, the Frigoboat started making abnormal noise, didn’t stop working and stop cooling.
After shutting it down for an hour, it started running as normal.
I know that Frigoboat made the mistake of not installing a dryer on their units like most other do and it was my intention to install one but I sold the boat before .
Nevertheless, I suggest anyone that experienced this kind ok issue with a Frigoboat to install a Dryer/filter.

[skipgundlach]

I'll be back...

A f k....

[a64pilot]

Quick disconnects make it easier to replace a component, like say for instance the cap tube were to get clogged by a piece of debris, with quick disconnects you can remove and replace with only hand tools and not have to have brazing equipment, nitrogen, a vacuum pump, etc.

[Richard Kollmann]

There are a few things you should understand about Frigoboat keel cooler refrigeration as it is not a conventional design. These keel cooler systems suffer from three design deviations not present on conventional boat refrigeration, lack of compressor cooling, location of filter/ moisture dryer, and improper O ring design line connector seals. Boaters with this keel cooler system who operate their boats in moderate seawater temperatures that limit compressor to a duty cycle of less than thirty minutes per hour should not need to worry about reliability.

Compressor cooling: of any water cooled only hermetically sealed compressor can expose it to high temperatures unless temperature of its return line is supplying cool enough refrigerant. Conventional system generally supplement compressor cooling with large amounts of ambient air, this is especially important when return cool gas is reduced at low evaporator temperatures. Prolonged high temperature operation on Danfoss BD compressors has resulted in oil flow contamination destroying complete system. Running refrigeration when boat is out of the water with only a keel cooler condenser will quickly shorten the life of your Frigoboat system.

Filter dryer and its location: Filter dryers come in many sizes and shapes. The system manufacture hopefully selects a filter dryer capable of collecting any small amount of contaminants and moisture left in a new system. On conventional refrigeration the filter dry is located in the liquid high pressure line after condenser and prior to refrigerant flow control device where its temperature is only slightly warm. Frigoboat keel cooler systems have the filter dryer in the return line next to the hot compressor iwhere it can not protect material blockage of orifice cap tube expansion device. Frigoboat reports point out another mistake with dryer too close to hot compressor discharged stored moisture into gas vapor circulating it again when it is heated.

Refrigerant final leak sealing, actual flow O ring, line seals: are not permanent seals. Conventional quick disconnects use only actual flow O rings to prevent loss of refrigerant during line connecting and final seal is when metal to metal seal is compressed.

My recommendation to a void future problems with solder brazing and its flux migration restrictions is to cut out present line connectors and replace with refrigerant quality heavy cast brass flare nuts and flared unions. As far as the filter dryer I would leave present filter as is and install a small 32 or 50 flared filter dryer some where in line from keel cooler to evaporator. The parts for this upgrade will cost around $ 25. I sold over 100 small compressor complete kits where these proper flare nuts were used.

Following this procedure I would pressurize system and leek test all new connection carefully before super dehydration, holding vacuum at 200 micron for at least 4 hours.
Super dehydration today with ester oil in system must include keeping complete system at around 100 degrees F, this includes evaporator temperature.

[skipgundlach]

Originally Posted by skipgundlach

I'll be back...

A f k....

Richard Kollmann's explanation covers the waterfront.

I desperately wish that those issues presented were known at the time of my installation, as my FB system, using a BD50, easily outperformed its replacement, a SeaFrost system using both water and air cooling despite also eating double the amps to achieve only a maximum pulldown of ~20F warmer.

On the subject of quick disconnects however I had no issues with my replacement of a failed seal, and the amount of gas needed to charge the system is so small by comparison that a single can would last me several complete evacuation and recharge cycles, should I have to do them (I did, many times, in the pursuit of what eventually was a total failure, covered on this forum 6 years ago).

It was only that my available opening in my top-load freezer prevented replacement of the largest - SS clad - evaporator offered which reluctantly led to my changeout of the system.

The gory details are here:
Pictures: Flying Pig 2013-2014 Shakedown/Refrigeration FINISH

[s/v Jedi]

The quick connectors are a nuisance but replacing the O-rings really solves leaking for 5 years so I would do that instead of replacing. Richard has the key with the filter/drier right after the keel cooler.

We are replacing our system after 15 years continuous use and the compressor units are still good.