Any holdover refrigeration users here?

[Roland Saul]

Greetings from Ottawa where it finally broke 65 degrees and people are running around half naked and delirious.... after a long winter the sun is a welcome sight indeed, perhaps nowhere more than right here among any Canadians on this forum....

I am continuing to think about lower-power options for the future, and was hoping to connect with someone who has built or used a holdover or pumpdown cooler. I see many options pre-made for boats and trucks, but to me it doesn't look too hard to build something custom and then connect a compressor/evap and cold plate. I suppose the success of it depends on training the family to open the case as little as possible, and to build a top-down access case that would be practical to use. I mean it takes x amount of energy to soak up the btu's in your food no matter which way you cut it, but the idea of only cycling the system once every few days appeals to me, especially considering the on-off availability of usable power. I realize that this method may appear a little strange, but I don't see it as too hard to build. Also to have the evap a few feet away outside the house, which would boost the efficiency in the summer. Like a minisplit except freezing the plate instead of cooling the air.

Any experience/pointers?? Anyone have a boat/ reefer truck using pumpdown plates?

Just curious about the practicality of building my own. I know there are propane and 12 volt alternatives ready-made, but the idea of pumping the fridge down and leaving it unpowered for a few days is attractive, even if I have to use the inverter or (gasp!) the genny to run the compressor.

[thastinger]

Man, screw scraping the ice off and only being able to open it once a day. I remember those on the sail boat. I think they still have application on a long distance sailboat but for modern off-grid PV systems I'd just convert a chest freezer.

[Roland Saul]

I take that as a "don't do it" then.... I figured if it was a "top door" arrangement then it wouldn't be as much a "only open it once a day" thing. I really like the idea of cooling the plate down for three hours then powering the thing off for a couple/three days. Still looking at compressors and plates... it's starting to seem a little far-fetched I suppose but no harm in examining the possibilities.

[thastinger]

My converted 7.2 CuFt chest freezer uses .512Kwh/day according to my kill-a-watt...and that is opening that thing over 30 times a day for various people to retrieve frosty beverages. That freezer is about 8 years old and wasn't even energy star rated when it was new. Just wouldn't be worth it to me to try to build something that marginally functions as a fridge as cheap as it would be to buy and convert a chest freezer.

You have to remember the environment the holdovers are designed for, start the diesel gen once or twice a day to recharge the battery but no 115 power available. You're essentially freezing a block of ice at the bottom of the fridge (or at least chilling the water) and that is what keeps it cool the rest of the day. They suck, I'm telling ya. The insulation is great on em because it has to be, they aren't efficient, just designed to use large amounts of power twice a day instead of a few minutes of run time each hour or two.

[Roland Saul]

I am finding out that there's a few really good 12/24 fridges out there. They cost at least twice as much per cubic foot as a 110 fridge, but seem to be way better insulated, and use little power. Wow, there's a half size fridge that uses 45 watts. Thanks for the insight, it seemed like a good idea but I wanted to hear from real users. At this point I'm liking your conversion idea too. There's a few 24 volt compressor units available. Still looking.....

[inetdog]

One thing that many people do not know is that foods, with sugar or salt along with the water in them, will be damaged by temperature cycling that does not go above 33F0C.
The ice crystals around the food will not thaw and refreeze, but the insides may.
What this means is that although putting jugs of water/ice in the box to try to stabilize the temperature is a good idea for a partially filled freezer or refrigerator, you actually need to measure the temperature extremes in a freezer to be confident that it is doing its job.

[thastinger]

I am finding out that there's a few really good 12/24 fridges out there. They cost at least twice as much per cubic foot as a 110 fridge, but seem to be way better insulated, and use little power. Wow, there's a half size fridge that uses 45 watts. Thanks for the insight, it seemed like a good idea but I wanted to hear from real users. At this point I'm liking your conversion idea too. There's a few 24 volt compressor units available. Still looking.....

45x24 = more than .5Kwh...and it's tiny...or maybe it doesn't run all the time

If youhad a 12 or 24V battery bank, they may work ok for you. I have a 48V bank so center taping isn't an option for me