Chest freezer conversion / inverter

[EricW]

This is a pretty specific question but I'll throw it out there anyway... chest freezer converted to fridge with the thermo shut off device. I was originally going to do that for my fridge but other than the fridge I don't have much AC draw. Anyone have any experience or insight who has done the chest freezer. The reason it's more of an issue is I am trying to rely on solar and considering downsizeine to an expensive 12v marine fridge because I could probably save 200 watts of solar and 2 batteries. Just seeing if anyone has any experience with this

[Iceni John]

Lots of folk have done this. Search the Northern Arizona Wind & Sun forum for plenty of info on this. Fridgers (that's my name for them!) are common in Australia, and I will be using one for my bus, maybe also with a small chest freezer for frozen food. There's no way I'll ever use something as intrinsically inefficient as a conventional upright fridge in my bus!

John

[Rusty]

Coleman Stirling Power Cooler are tough to find, but sip the juice @ 48 watts. I forget who made these for coleman, some Japanese company maybe?

doesn't use conventional cooling. very popular on boats. I've got one and it was $800 several years ago, so not super cheap.

link

It was used in the so-called hot air engine, which was considered at the time to be capable of replacing the steam engine. This was partly because the boilers used in early steam engines were prone to explosion. The counterpart of the hot air motor, the refrigerator, was first recognized in 1832. Both machines experienced high and low points during the nineteenth century. Scottish minister, Robert Stirling

The principle behind the machines was almost condemned to obscurity after the invention of the internal combustion engine (gas-, petrol-, and diesel motors) and compressor refrigerators with external evaporation.

In 1938 Philips Research Laboratories was looking for a means of generating electricity to power radios in remote areas where there was no electricity supply. The practically-forgotten hot air motor attracted attention. In 1946 Philips started studying the cooling techniques used in the Stirling cycle. The result was the development of the cold gasrefrigerator.

This machine, the cryogenerator, marked the start of significant cryogenic activities at Philips. So even though the Stirling hot air motor never became a commercial success, the Stirling cryogenerator is incorporated in equipment used from Antarctica to the North Pole.

In 1990, Philips’ cooling-related activities became independent and eventually continued under the name of Stirling Cryogenics BV. Thanks to continual innovation and considerable investment in R&D, the Stirling cryogenerator is now used in advanced technological machinery for cooling gases and liquids to extremely low temperatures
(200 K to 20 K).

Applications with Stirling cryogenerators are used in a wide range of applications, including the production of liquid gases, cooling gases and liquids, and cooling during (industrial) processes.

[brokedown]

I've done the chest freezer in my bus, my friend did one is his box truck. He actually set up all the automatic stuff, I bought all the parts to automate it but so far just manage it manually.

My friend put a piece of foam to effectively separate it into a functional freezer on one side and a fridge on the other.

I have a 4.5 cubic foot chest freezer I got on sale at Walmart. I can run it for 20-30 minutes per day and maintain temperature in hot climate. I'm in Berkeley right now (72 degrees!) and I haven't had to run it for 3 days. which is good because I'm parked under some shade trees so my solar is doing very little.

When I first bought it, I measured its power draw with a kill-a-watt for its initial cool-down and it was pulling under 90 watts.

[joeblack5]

Thanks Rusty,
I think the stirling cooler units were made by global cooling. The units are still made for the medical organ donor transport. We use one as a freezer in Elfie.

I think by now the efficiency of normal compressor coolers is at par with stirling coolers. Our dometic 12/24 fridge is also very efficient.

The main efficiency is determined with heat losses and inadequate insulation.
Small freezers are better insulated and that why they are more efficient when used as fridge.
It is easy to insulate a fridge or freezer with additional insulation as long as you choose a unit that has a separate condensor. Most modern fridges and freezer have the condensor integrated in metal outer skin of the fridge. So additional insulation of those surface is impossible.

Later J

[Rusty]

Thanks for the good info ! Just putting a small shout-out to alternative cooling.

I was initially planning on a freezer conversion, but 'other input' said she wanted vertical. Efficiency wins every time. I already have the small chest freezer, so no brainer.

R-

[Njsurf73]

I use a "keeser" for my home brew, and it is an energy sipper compared to my upright refrigerator.

Sent from my XT1254 using Tapatalk

[joeblack5]

fleaybay

stirling cooler

263077792233

$ 250

pretty good price, I paid $500 for mine

later J

[Brewerbob]

Originally Posted by EricW

This is a pretty specific question but I'll throw it out there anyway... chest freezer converted to fridge with the thermo shut off device. I was originally going to do that for my fridge but other than the fridge I don't have much AC draw. Anyone have any experience or insight who has done the chest freezer. The reason it's more of an issue is I am trying to rely on solar and considering downsizeine to an expensive 12v marine fridge because I could probably save 200 watts of solar and 2 batteries. Just seeing if anyone has any experience with this

Haven't read the responses (yet) but I've done this at home for beer lagering. You can buy a thermostat controller for something like $50. The one I have is by Johnson Controls. You plug it into the wall then plug the freezer into it. It has a thermocoupler on a long lead that you put in the chest freezer. Set the dial anywhere between 30° and 80°. The link below is just a random link. You can buy something similar in a variety of different temp ranges and either +/-3° or +/-12°.

Johnson Controls Refrigerator Thermostat - Northern Brewer

[Livity]

We use a chest freezer and they are really efficient, it pulls little on our solar. We have a med size frige that didn't work and we have it layed on its back so it's like a super insulated chest cooler and we put half gal ice blocks in it from our chest freezer. This seems to work really well because the chest design keeps the cool down there when you open it and friges are well insulated, we exchange our ice blocks every 2-3 days in cool seasons and once a day in summer, so we have no energy pull for frige and don't have to use propane frige. The ice jugs condensate so we have to dry the bottom of the frige ever so often... We are also considering another chest freezer to convert to frige temps, it's been highly recommended, they are so efficient we can probably power both.