12 volt refrigeration repair or replace?

[Uncle Bob]

Originally Posted by Richard Kollmann

Uncle Bob you keep advertising your Ozefridge but say nothing about your unit and details of your Ozefridge: size of box, age of unit. and daily energy consumption based on ambient temperatures. Pictures would also help.

Richard, I am not in any way connected with Ozefridge, I have a refrigerator in my boat that from day one has been barely tolerable and was then introduced to the Ozefridge on a friends boat, chalk and cheese, then found others with the same product and recognised quality of manufacture and design. I was so impressed with the logical and practical design I contacted Pete when he was a member here and complimented his product, and will continue to suggest to anyone with refrigeration blues that a conversation with them would not go astray.
Sorry if that offends you, however I would strongly recommend to anyone that researching a product and sourcing from an established current manufacturer is the only really practical way to go.
Another aspect to consider is aftersales support and assistance. Priceless.

[Jill on Maya]

Fridge technician attended this morning.
Update on our 14 year old Isotherm Compact Classic system with Danfoss BD35F compressor and SP (self pumping) thru hull type salt water cooled condenser/heat exchanger. Problem first noticed 4 months ago is loss of refrigerant via slow leak. Fridge technician attended then and tested for leak by using dry nitrogen at 200PSI. He found no leaks, checked/tightened all connections anyway and re-gassed. Fridge worked fine until we noticed reduced efficiency a week or two ago. With input from CF postings and the technician we opted for a simple re-gas from him today, then with pressure restored we did bubble tests at lines and connection points. Bubble testing has not located any leak. So we now suspect the inaccessible salt water cooled condenser that many say are a weak point in the system.

Having spent some hours researching options our current thinking is that if/ when refrigerant leaks again we will replace the whole system. The Ozefridge concept with its eutectic plate has won us over. It makes so much sense and the many positive reviews on the design, quality and technical support make it an easy decision. It comes pre-gassed and with instructions for DIY. We will probably spend the extra for the air and fresh water cooled set up for the increased efficiency (i.e. reduced power for same cooling).

I understand why some posters are opting for 12V off the shelf portable fridges but we already have a very nice, well insulated and convenient to use built in upright fridge (with shelves!) with a front opening door. It deserves to be recommissioned with a new updated cooling system. When the time comes we will take advantage of the Ozefridge offer on their website "Prior to suggesting or supplying a system, we offer an obligation free project assessment so that the package offered is the most suitable, provides the refrigeration outcomes expected in the environment nominated, and with a known power consumption." I like that. Thank you Ozefridge. And thank you all CF posters for your input.

[Richard Kollmann]

Originally Posted by OzeLouie

Richard I think you may be confused. Bob has never said he owns an Ozefridge system nor does he have any connection to our company. Bob is a Sydney based friend of ours, has seen many of our systems there and appreciates what we are building.
For the information you seek it may be best to check out this CF thread: https://www.cruisersforum.com/forums...ws-136455.html or www.ozefridge.com The web site describes the various systems in detail with pictures, data, diagrams and easy to follow commentary. I'm sure you will find it very interesting.

BTW, you mention posting pictures yet my attempts here at CF and elsewhere to find pictures, data or schematics to support you or your company as 'hands on refrigeration', failed!
Perhaps you could post some pictures etc depicting your past system building activities?

I am sorry that you did not understand why I assumed Uncle Bob who contributes regularly hear had one of OzePete's designs. I frequently ask boaters who have less popular boat refrigeration systems for information about their unit and also installation pictures. Over the years I produced four books on boat refrigeration application and available manufacturer's designs. When I find I lack information of a design I ask anyone with a less popular system for their opinion of it. I revisited the links you posted and contacted your manufacture in the past but was unable to get any technical facts normally provided by others, such as, Manufacturer's of components like compressor, Refrigerant charge volume, or a customary technical manual.
As far as My pleasure boat refrigerator designs and pictures there are over at least seventy different designs in my books, the DIY book contains 60 different boat models eutectic custom Holding plates pictures all delivered around the world before I retired the second time at 80. Now at 87 I must admit I am another arm-chair technician.

[OzeLouie]

Originally Posted by Richard Kollmann

I am sorry that you did not understand why I assumed Uncle Bob who contributes regularly hear had one of OzePete's designs. I frequently ask boaters who have less popular boat refrigeration systems for information about their unit and also installation pictures. Over the years I produced four books on boat refrigeration application and available manufacturer's designs. When I find I lack information of a design I ask anyone with a less popular system for their opinion of it. I revisited the links you posted and contacted your manufacture in the past but was unable to get any technical facts normally provided by others, such as, Manufacturer's of components like compressor, Refrigerant charge volume, or a customary technical manual.
As far as My pleasure boat refrigerator designs and pictures there are over at least seventy different designs in my books, the DIY book contains 60 different boat models eutectic custom Holding plates pictures all delivered around the world before I retired the second time at 80. Now at 87 I must admit I am another arm-chair technician.

"less popular boat refrigeration systems" Very disingenuous!
I had hoped that we could both contribute positively to refrigeration issues for members here at CF without this type of petty sniping or grandstanding!

At Ozefridge we manufacture complete systems on a weekly turn around of usually 15 systems at a time. We only employ qualified refrigeration technicians for this hands on work as most systems are somewhat customised to suit each specific project. (Hardly a "less popular boat refrigeration systems"... BTW regards your actual past system manufacture, any pictures of same as it would be interesting to compare your manufacturing processes back then with today. Pictures or links would be good.

Richard, I notice you did check out our web site but suggest you look at the other 13 pages and not just the 'Home' page for the answers you seek. Try starting here https://www.ozefridge.com/about-us and then the other pages.
Would be interested in comments after you have a chance to consume all of our web site material!

[Sailingmartin]

Jill. Just going through the same process of replacing a 1990s Isotherm unit. It is also water cooled - not through the sink drain but with two dedicated through hulls, in and out. I like the look of your Ozefridge but the standard unit is just a bit too big for the space the current Isotherm takes up.

Looks like we will be replacing ours with a Frigoboat water cooled version which uses the common Danfoss 35 compressor. The air cooled version is much cheaper but we are off to sail in the tropics and hope the water cooled one will be more efficient. Good luck with your new fridge!

[malbert73]

Originally Posted by Sailingmartin

Jill. Just going through the same process of replacing a 1990s Isotherm unit. It is also water cooled - not through the sink drain but with two dedicated through hulls, in and out. I like the look of your Ozefridge but the standard unit is just a bit too big for the space the current Isotherm takes up.

Looks like we will be replacing ours with a Frigoboat water cooled version which uses the common Danfoss 35 compressor. The air cooled version is much cheaper but we are off to sail in the tropics and hope the water cooled one will be more efficient. Good luck with your new fridge!

Are you installing a keel cooler version?

[Jill on Maya]

Originally Posted by Sailingmartin

Jill. Just going through the same process of replacing a 1990s Isotherm unit. It is also water cooled - not through the sink drain but with two dedicated through hulls, in and out. I like the look of your Ozefridge but the standard unit is just a bit too big for the space the current Isotherm takes up.

Looks like we will be replacing ours with a Frigoboat water cooled version which uses the common Danfoss 35 compressor. The air cooled version is much cheaper but we are off to sail in the tropics and hope the water cooled one will be more efficient. Good luck with your new fridge!

Has your 1990's Isotherm failed and if so did you find source of failure - was it at the condenser? I haven't found any threads on the usual life of the Danfoss BD35 compressor and the rest of the system. CF posters indicate that salt water cooled condensers are a weak point (electrolysis) in the system. BTW Ozefridge will supply (at under A$100) an air cooled condenser or an air and freshwater cooled condenser which can be added (brazing required) to existing system to replace the salt water cooled condenser if that is the source of Isotherm failure. Just saying ........

[Gerrycooper56]

Originally Posted by Jill on Maya

Question: Seeking advice on the usual lifespan of an Isotherm Compact Classic with a water cooled SP (self pumping) condenser. Is it time to just replace the whole or worth trying again to find and fix a very slow leak?

Background:

We have an Isotherm Compact Classic 12v refrigeration system that runs a 100 litre upright fridge. (The fridge can also be run from an engine driven eutectic system). Best guess is that the system was fitted when the yacht was built in 1994. On board records show installation of a new SP water cooled condenser kit in 2007 in preparation for an extended long term voyage which included some months in the tropics. The system was re-gassed in 2014 then ran without concern until December 2020 when it showed reduced cooling, the compressor (Danfoss BD35F) was running but not cycling in the usual way. Refrigeration mechanic tested for leaks (using helium gas I think he said), unable to find any leak, tightened loose connections on flare nuts on gas lines, evacuated lines to remove any moisture then re-gassed with the small amount (70ml) of R134a that the system holds. We concluded that this type of refrigeration system might just need to be re-gassed every 5-7 years. It then ran as usual for about 4 months until it again showed reduced cooling and the compressor started to run more often but at lower amps. We assume it has again lost gas. In Australia access to refrigerant gas is restricted to certificated tradesmen so each re-gassing is a more costly exercise. Because it has a water cooled condenser (fitted in the galley sink outlet), a leak at this component can't be found until next haul out in about 7 months. If that is where the leak is, what is likelihood that it will be repairable? If we decide on a complete replacement, are air cooled systems cheaper or more reliable than water cooled? Not complaining about longevity of the system we have but just don't want to spend time and money trying to fix something that is better replaced.

We recently replaced a water cooled eutectic system with an air cooled danfoss/evaporator plate system. Our compressors are the BD50 and are configured at the lowest run speed of 2000rpm. I would consider replacing the water cooled with an air cooled system, mounting the compressor as close to the hull as possible and low down. We are in Panama and have had no cooling issues to date. I believe the fixed speeds can be 2000, 3000 and 3500 rpm so for longevity and lower power draw I would go with the slightly larger but lower revving compressor.

[cottonsail]

The best freon detector used a propane torch. The propane heated a small disc. A small hose from the disc is what you used to sniff for freon. When freon was detected the propane would flare up dramatically. It was the best detector but very dangerous. Additionally when it detected freon and flared up it gave off phosgene gas.

[Icarus]

Originally Posted by Jill on Maya

Question: Seeking advice on the usual lifespan of an Isotherm Compact Classic with a water cooled SP (self pumping) condenser. Is it time to just replace the whole or worth trying again to find and fix a very slow leak?

Background:

We have an Isotherm Compact Classic 12v refrigeration system that runs a 100 litre upright fridge. (The fridge can also be run from an engine driven eutectic system). Best guess is that the system was fitted when the yacht was built in 1994. On board records show installation of a new SP water cooled condenser kit in 2007 in preparation for an extended long term voyage which included some months in the tropics. The system was re-gassed in 2014 then ran without concern until December 2020 when it showed reduced cooling, the compressor (Danfoss BD35F) was running but not cycling in the usual way. Refrigeration mechanic tested for leaks (using helium gas I think he said), unable to find any leak, tightened loose connections on flare nuts on gas lines, evacuated lines to remove any moisture then re-gassed with the small amount (70ml) of R134a that the system holds. We concluded that this type of refrigeration system might just need to be re-gassed every 5-7 years. It then ran as usual for about 4 months until it again showed reduced cooling and the compressor started to run more often but at lower amps. We assume it has again lost gas. In Australia access to refrigerant gas is restricted to certificated tradesmen so each re-gassing is a more costly exercise. Because it has a water cooled condenser (fitted in the galley sink outlet), a leak at this component can't be found until next haul out in about 7 months. If that is where the leak is, what is likelihood that it will be repairable? If we decide on a complete replacement, are air cooled systems cheaper or more reliable than water cooled? Not complaining about longevity of the system we have but just don't want to spend time and money trying to fix something that is better replaced.

I have an air-cooled Isotherm unit on my boat since 2005, no issues. I prefer the air-cooled system as it can be operative while the boat is out of the water
Looks to me you have a gas leak at the cooler at the sink outlet. I would check it out before splashing out for a new system.
It doesn't take much of a leak to lose a lot of refrigerant gas.

[Davo1404]

Originally Posted by Jill on Maya

Fridge technician attended this morning.
Update on our 14 year old Isotherm Compact Classic system with Danfoss BD35F compressor and SP (self pumping) thru hull type salt water cooled condenser/heat exchanger. Problem first noticed 4 months ago is loss of refrigerant via slow leak. Fridge technician attended then and tested for leak by using dry nitrogen at 200PSI. He found no leaks, checked/tightened all connections anyway and re-gassed. Fridge worked fine until we noticed reduced efficiency a week or two ago. With input from CF postings and the technician we opted for a simple re-gas from him today, then with pressure restored we did bubble tests at lines and connection points. Bubble testing has not located any leak. So we now suspect the inaccessible salt water cooled condenser that many say are a weak point in the system.

Having spent some hours researching options our current thinking is that if/ when refrigerant leaks again we will replace the whole system. The Ozefridge concept with its eutectic plate has won us over. It makes so much sense and the many positive reviews on the design, quality and technical support make it an easy decision. It comes pre-gassed and with instructions for DIY. We will probably spend the extra for the air and fresh water cooled set up for the increased efficiency (i.e. reduced power for same cooling).

I understand why some posters are opting for 12V off the shelf portable fridges but we already have a very nice, well insulated and convenient to use built in upright fridge (with shelves!) with a front opening door. It deserves to be recommissioned with a new updated cooling system. When the time comes we will take advantage of the Ozefridge offer on their website "Prior to suggesting or supplying a system, we offer an obligation free project assessment so that the package offered is the most suitable, provides the refrigeration outcomes expected in the environment nominated, and with a known power consumption." I like that. Thank you Ozefridge. And thank you all CF posters for your input.

You will be very happy with your choice of Ozefridge. They provide excellent service and advice. We have been sailing around the Queensland coast since 2007. That is when we fitted our first Ozefridge Eutectic system with the fresh water cooling. It ran 24 / 7 for 13 years. Started having a few issues, so with consultation with a fridge technician and Ozefridge we decided to upgrade. Installed a new unit in February. Used the original tank and pipes. The new unit only uses the fans on high speed and the fresh water cooling when the condenser reaches 43c. Fridge is 450 by 450 by 500 mm. Temperature maintained at 3 to 6c. Runs twice in 24 hours. Each run time is around 2 hours. Total amps is around 35 per 24 hours. This is with a sea water temperature of 30 to now 25c & yacht inside temperature of around 30c. The water pump & high speed mode on the fans only operate for a few minutes per the 2 hour run.

[Jill on Maya]

Originally Posted by Davo1404

You will be very happy with your choice of Ozefridge. They provide excellent service and advice. We have been sailing around the Queensland coast since 2007. That is when we fitted our first Ozefridge Eutectic system with the fresh water cooling. It ran 24 / 7 for 13 years. Started having a few issues, so with consultation with a fridge technician and Ozefridge we decided to upgrade. Installed a new unit in February. Used the original tank and pipes. The new unit only uses the fans on high speed and the fresh water cooling when the condenser reaches 43c. Fridge is 450 by 450 by 500 mm. Temperature maintained at 3 to 6c. Runs twice in 24 hours. Each run time is around 2 hours. Total amps is around 35 per 24 hours. This is with a sea water temperature of 30 to now 25c & yacht inside temperature of around 30c. The water pump & high speed mode on the fans only operate for a few minutes per the 2 hour run.

Thanks for that very useful information and data and comments from previous posters. According to description on the Ozefridge website the compressor used on the current model is 3.5cc variable speed. I assume that one of the advantages of variable speed is that it increases/reduces the rpm (and corresponding amps, noise, wear) only as required to maintain temperature. At this point having been unable to find the leak we are crossing fingers that our long lived Isotherm Classic does not lose refrigerant again. (Miracles have been said to happen.) We have back up engine driven refrigeration and no long range cruise planned so can take the risk.