Ice Box Refrigeration Conversion Engle?

[Richard Kollmann]

gspeak, For miscghief's boat's box a Ozfridge unit would be like putting a 400 horse power engine in a motorcycle. Eutectic holding plates are not more efficient they are only used to store surplus energy.

[gspeak]

I wasn't sure of his size. However, I find that our unit comes on for only 3 to 4 hours a day using approx. 6 amps so maybe 24 amps per day in the tropics. I question your notion of the overall system not being more efficient especially if hooked up using the water cooling via our water tank">fresh water tank.

We find it to be very efficient. Though you might have a different definition of efficiency. I'm no expert, but just a happy customer.

The much smaller Engel uses over 30 amps a day, as a freezer set on "3". But would expect it to be so, less efficient with its lack of comparable insulation etc.

Dave

Originally Posted by Richard Kollmann

gspeak, For miscghief's boat's box a Ozfridge unit would be like putting a 400 horse power engine in a motorcycle. Eutectic holding plates are not more efficient they are only used to store surplus energy.

[RaymondR]

I thought the Ozefridge units were fairly pricey but did not make any comparisons with other available kit systems.

If you purchase the components and build it yourself you could probably budget in the $1,000 - 1,200 range. The compressor is the expensive bit for which you will pay $800 - 900 for a Danfoss or a lot less for a similar Chinese unit. The last time I went through the budgeting process I found that it was cheaper to buy a portable unit and pirate the parts from it than to buy them as components.

Getting your hands on the gas is the big problem but if you are willing to use one of the hydrocarbon based refrigerants this is not a problem. According to the experts it is dangerous because it forms an explosive mixture with air but since most boats use the same gasses for cooking and a refrigeration system only has 100 grams or so of refrigerant and it is extremely unlikely that a leak would be big enough to provide sufficient gas to form a harmful mixture. In comparison to what could be created by a gas stove the risk associated with hydrocarbon refrigerant appears vanishingly small.

If you are the sort of person that loves a challenge and doing things yourself a possibility is that you buy a portable unit and use it whilst you clue up on refrigeration and build your box then pirate it to do the boat frig installation.

[zboss]

I'm also looking closely at the Engel fridge's (40 qt. drop-in) but reliability is a concern for me. Are these fridges breaking down on a regular basis?

The boat came with a Danfross system but its not working (compressor seems to run but doesn't cool). I am reluctant to pile money into something that may just break down again and again.

[Richard Kollmann]

Repair or replace is not always a simple decision. If this is a standard air cooled Danfoss compressor system and compressor is confirmed to continue to run with no cooling it is a refrigerant problem. Best way to confirm compressor is running is to let it run for 30 minutes and it will get warm to the touch or if you have an ammeter it will draw more than 2.5 amps if running. The most expensive units to repair are water cooled units like the keel cooler models if you can not do the work yourself. If test indicates compressor is not running problem is a simple electrical problem anyone can repair.

Before I finished my 12/24 volt refrigeration book I ran a number of tests on ENGEL’s 40 Qt portable unit and was amazed how well it performed as a cooler, refrigerator or a low temperature freezer. All tests were done with an 80 degree controlled ambient air test room temperature. Test results on box insulation at a box temp of -4 degrees F resulted in a delta T of only 4 degrees across insulation. As far as reliability and longevity the Engel needs to be located out of the sun and away from seawater spray. I once worked on one of these twenty year old units on way around the world and all that was wrong was the power cord.