The Worst pleasure boat refrigeration.

[Pete7]

Originally Posted by GILow

Fridge insulation as per Ozefridge’s recommendation, 150 mm for the base, 100 mm on the sides and 50 mm on the top. Using extruded polystyrene as it was all I could easily source.

When I hear about excessive power consumption on any refrigeration system I am more inclined to ask about the state of the insulation.

That's a huge variation in insulation between the bottom and the top which I hadn't appreciated was a good practice, presumably applies to any type of fridge. Might need to re-visit our fridge, even if I can't achieve that thickness, perhaps there is more that can be done even for those living in the frozen North. Saves leaving it outside in a bucket to freeze overnight

Pete

[GILow]

Originally Posted by Pete7

That's a huge variation in insulation between the bottom and the top which I hadn't appreciated was a good practice, presumably applies to any type of fridge. Might need to re-visit our fridge, even if I can't achieve that thickness, perhaps there is more that can be done even for those living in the frozen North. Saves leaving it outside in a bucket to freeze overnight



Pete

I was surprised too, but it works well so far.

Adelaide has very low humidity so I can’t say that condensation won’t form on the top, but it certainly does not feel cold enough on the lid for me to worry too much.

[s/v Jedi]

I just tore out my old refrigeration. I had 7” insulation on the bottom and 6” on top for the freezer, 4” on the fridge. Sidewalls were all 4”.

My new will be 3” with top opening, nice magnetic seals, led lighting, stainless steel finish etc. We went for SnoMaster Expedition series

[Dougtiff]

I installed a AIR COOLED NORCOOL [12V.] drop in unit in a customers box, had an old unit [R12], that had died, the new unit vibrated so badly, even with Hugh rubber mounts, then it died, returned to vender, got another unit [under warrenty], same thing, returned, looking into another brand.

[Cpt Mark]

I went with a SnoMaster box chest and dropped it in. Worked great, almost silent, just a bit of noise from the fan. 5 year warranty. Very well built.

And then I took it out because of the way it sat, it stuck up because of the latches above the counter top and while it was huge... interior volume wasn't what I wanted for a cruising boat.

I have since removed it and gone back to a very well insulated box etc

[ayates]

Originally Posted by bobty

Yes me too. I decided on Ozefridge because of other satisfied customers https://www.cruisersforum.com/forums...ws-136455.html and am a very happy customer now. I also had been following Ozepetes thread on eutectics until it disappeard. I see there is a copy here of those tests https://www.ozefridge.com/trial-data Thanks

I always had a really good feeling from Ozefridge the company and Ozepete the person in my (private) discussions with him. However, I was never convinced of the difference in power consumption, especially as even that tests page says the difference is not always as great as indicated. As well, I have never seen any test results which include temperature logging. Is a freezer a solid -20C continuously for example, does a fridge maintain 4C, etc.

I would love to do a proper comparison of the two approaches, but cannot stomach the cost just to satisfy my curiosity.

I did do proper testing comparing the Stainless Steel Lobster controller with the OEM thermostat. The Lobster significantly reduced energy consumption, but at the expense of freezer temperature in my application. Amazing, personalised, technical support from the owner though. Would highly recommend him.

In the end I went with a commercial Nova Kool unit. I do have another refrigeration use case in mind, so I am keeping an open mind.


Allan.

[s/v Jedi]

Originally Posted by Cpt Mark

I went with a SnoMaster box chest and dropped it in. Worked great, almost silent, just a bit of noise from the fan. 5 year warranty. Very well built.

And then I took it out because of the way it sat, it stuck up because of the latches above the counter top and while it was huge... interior volume wasn't what I wanted for a cruising boat.

I have since removed it and gone back to a very well insulated box etc

Yes, I am installing them under the countertop, in sliding trays like a drawer. It requires new galley cabinets.

[Bill O]

Originally Posted by s/v Jedi

I just tore out my old refrigeration. I had 7” insulation on the bottom and 6” on top for the freezer, 4” on the fridge. Sidewalls were all 4”.

My new will be 3” with top opening, nice magnetic seals, led lighting, stainless steel finish etc. We went for SnoMaster Expedition series

Just curious why you would want to go w/a chest type fridge or freezer when you had previously much more insulation in your old ones. If I remember correctly I believe your old system was a fridgoboat in both fridge and freezer.

Had an Engel type before and thought it was under insulated and consumed a great deal of power for what it was.

[RaymondR]

Originally Posted by ayates

I always had a really good feeling from Ozefridge the company and Ozepete the person in my (private) discussions with him. However, I was never convinced of the difference in power consumption, especially as even that tests page says the difference is not always as great as indicated. As well, I have never seen any test results which include temperature logging. Is a freezer a solid -20C continuously for example, does a fridge maintain 4C, etc.

I would love to do a proper comparison of the two approaches, but cannot stomach the cost just to satisfy my curiosity.

I did do proper testing comparing the Stainless Steel Lobster controller with the OEM thermostat. The Lobster significantly reduced energy consumption, but at the expense of freezer temperature in my application. Amazing, personalised, technical support from the owner though. Would highly recommend him.

In the end I went with a commercial Nova Kool unit. I do have another refrigeration use case in mind, so I am keeping an open mind.


Allan.

My recollections tend to be a little unreliable these days but I do seem to recall that the Ozefridge tests did include temperature logging. I seem to recall the distinctive temperature rise when the eutectic all melted and before the compressor kicked in to begin the re-freezing process.

With eutectic the temperature will tend to remain constant whilst either the melting or freezing phase changes of the eutectic fluid is taking place. The tank full of liquid also provides thermal inertia to resist rapid temperature changes.

A titbit for the scientifically inclined.

Decades ago Australia's premier research institute, the government funded CSIRO, needed very high precision diffraction gratings so they built a super accurate ruling machine. The machine scribed very closely spaced lines on a piece of optical glass.

The technicians found that the expansion of the metals from which the machine was made due to temperature changes caused the scribed lines to differ in spacing. So they set about environmentally controlling the room the machine was used in. However, they discovered that the best technology of the day could not provide sufficient temperature control to solve the problem.

The solution proved to be situating the machine in an underground vault in one of the city of Melbourne's oldest bank buildings. The technician would set the machine up and it would sit for a few weeks doing nothing whilst the body heat introduced by the technician soaked away then proceed with the scribing. Whilst Melbourne's four seasons in a day weather was raging outside the thermal mass of the stone building would keep the temperature at the machine within a decimal fraction of unchanging.

And no, I don't know what they powered it with to keep the power source from introducing heat, weights and gears like a grandfather clock maybe.

[GILow]

Originally Posted by Dougtiff

I installed a AIR COOLED NORCOOL [12V.] drop in unit in a customers box, had an old unit [R12], that had died, the new unit vibrated so badly, even with Hugh rubber mounts, then it died, returned to vender, got another unit [under warrenty], same thing, returned, looking into another brand.

Get an Ozefridge. You won’t be disappointed.

[s/v Jedi]

Originally Posted by Bill O

Just curious why you would want to go w/a chest type fridge or freezer when you had previously much more insulation in your old ones. If I remember correctly I believe your old system was a fridgoboat in both fridge and freezer.

Had an Engel type before and thought it was under insulated and consumed a great deal of power for what it was.

Engel has 2” of insulation, where Snomaster has 3”. That’s a lot better. Compared to 4” the Snomaster still wins because it seals are much better and it’s compressor and evaporator are matched perfectly (like with Engel).

I have completed extensive power consumption testing and these units win from my old system. Now that I tore out the old, I found some voids, some wet foam etc. And all that quickly adds up. Seals and front opening were big setbacks of the old system.

The Engel was the trendsetter but now it has been surpassed by the other brands because they have been complacent while the others caught up and overtook them. An extra inch of foam and stainless steel finish makes quick work of the comparison.

It is a lot of work to rebuild the refrigeration but after so many years the old system was too far gone to keep on life support. It wasn’t a bad run asI installed that in 2004, so 15 years, that ain’t bad.

[Uncle Bob]

Originally Posted by GILow

Get an Ozefridge. You won’t be disappointed.

I guess if Ozepete was still here he would be pleased with the positive responses to his product. If I recall, it appears only one alluded to complaint posted by Richard.

[Richard Kollmann]

Uncle Bob, You are always promoting eutectic plate systems over the more poplar refrigeration. I have two questions describe your refrigeration systems performance with eutectic plate? Do you have alternative energy from solar panels, a must for eutectic plates on boxes larger than 4 cu ft and if energy is provided by a compressor capacity of less than 1,000 Btu?

[Uncle Bob]

Originally Posted by Richard Kollmann

Uncle Bob, You are always promoting eutectic plate systems over the more poplar refrigeration. I have two questions describe your refrigeration systems performance with eutectic plate? Do you have alternative energy from solar panels, a must for eutectic plates on boxes larger than 4 cu ft and if energy is provided by a compressor capacity of less than 1,000 Btu?

Richard, hi, as I have said previously I do not have a eutectic system on my boat, if I was replacing it I would definitely go down that path and with the 190 watts of solar panels on my boat they keep the relatively large battery bank well topped off with the existing refrig system running 24/7.
The only experience that I have had with eutectic systems has been on OP's boats and they have all been positive and very pleased with theirs.
Solar generation is in my opinion the single biggest game changer for marine refrigeration since the days when fridge power was derived from engine driven compressors.
Coupled with controls that can run the system when power is abundant they are a great solution for many if not most.

[GILow]

Originally Posted by Richard Kollmann

Uncle Bob, You are always promoting eutectic plate systems over the more poplar refrigeration. I have two questions describe your refrigeration systems performance with eutectic plate? Do you have alternative energy from solar panels, a must for eutectic plates on boxes larger than 4 cu ft and if energy is provided by a compressor capacity of less than 1,000 Btu?

I don’t get this thing about needing alternative energy for eutectics.

50 AH is hardly difficult to replace using any number of power sources. What am I missing?