DIY super efficient fridge.
 

Well its sort of a DIY.

Someone in Australia has come up with a simple conversion that will turn a chest freezer into a refrigerator that uses about 0.1 kWh per day (that is 93% less electricity than a normal fridge).

Mr. Electricity Link

how to make a super-efficient fridge

Pimp! Def gonna bookmark this! Thanks for the links! :D

WAY COOL! :thumbup: :thumbup: It shouldn't be very hard at all to convert that to 110/120 volt for use here in the USA.

Someone on another forum I go to posted it. I thought someone on gassavers might like it.

things like this have been around for many years, $65 will buy you one marketed twards home brewers, Check this out
Of course there are a number of chest type fridges on the market, and if you want to just save energy in the winter, SunFrost used to sell a heat pipe option to their fridges, but no one understood them, so they didn't want the added cost.

Interesting. It's just a chest freezer with a new thermostat. His thermostat is a bit complicated due to it using zero power when not on.

I have an older fridge that I was thinking of replacing because it uses quite a lot of power (almost 5 kWh/day). Since I already have a chest freezer, the only challenge would be the footprint of a chest for a fridge. They make fairly small chest freezers though, and you wouldn't need a big one.

That's my understanding too. And isn't that the kind of "thinking outside the box" that we like here at gassavers. ;)

But IMHO the really nice thing about this, is that your total cost of doing this is the cost of a chest freezer (and those are reasonably cheap, and frequently have much more insolation than most "fridges" do) plus the plug in thermostat. And if you look around, you can get digital (control to 1 degree) 110v "plug in" (just plug the freezer into the thermostat's outlet instead of the wall, and you are "good to go") for around $100 (or even less if you go with the less accurate analog thermostats). And as far as I can tell, that "plug in thermostat" is all you need beyond the chest freezer (and any shelving you want to put in the freezer to make it more usable). So this should not only be an energy efficient "fridge", it should be a reasonably inexpensive one as well (likely cheaper than many "normal" fridges).

And if you ever want to remove the "conversion" (and use your freezer as an actual freezer), you just unplug the freezer from the thermostat, and plug it back into the wall (at which point the internal freezer thermostat will take over). So it is trivial to switch back and forth between "fridge" and "freezer", by simply using/removing the external "plug-in" thermostat (i.e. this "mod" is trivial to "reverse" if/when desired)!

BTW:
I haven't yet tried the freezer to fridge mod (but it is something I'm seriously considering in our house), but I'm pretty sure the theory is sound (i.e. it should work).

In fact, with some chest freezers, cutting the power occasionally is useful even if/when you want to keep your freezer as a freezer. For example, I did some tests, and discovered that I could put a digital 24 hour (appliance) timer on my chest freezer (around $18 at the hardware store), and set it to only power the freezer around 40 minutes every 2 hours (you need the digital timers for this, the cheaper analog units don't have fine enough control). My experiments showed that this is still often enough to keep things frozen in the freezer, but this approach saves over 1/2 of the power the freezer was using when plugged directly into the wall. This worked for me, because my freezer always uses over 150watts when plugged in (as verified by my Kill-A-Watt meter), even if/when the internal thermostat was set to kick off (and more power than that when the freezer was actively trying to cool things down). But with the timer, when the power is cut, the power is cut (the only power then being the less than a watt used by the appliance timer itself). And while the freezer does work a little harder when it's on (to cool things down, after they have warmed up a little with the power cut), that still results in over 1/2 of the power the freezer was previously using being saved. Granted this still works out to only about $4/month of electrical savings, but that's still something...

On another board I haunt a guy has done this and come up with some additions. A small fan, a drain to get rid of the condensate. Check it out.

https://www.wind-sun.com/smf/index.php?topic=1073.0

Actually that whole sub topic is good for general power efficient mods for the home :)

This is a great idea. I have yet to try it, but I have the perfect size chest freezer (6.3 cu ft) for the conversion. If anyone gets the thermostat, let me know how it works. For now we are using the freezer as a freezer, and for a fridge we are using the super efficient method of unplugging the fridge and storing stuff in the cold pantry. Works great here in VT.

One problem of using a timer to keep the freezer from always having access to power: larger swings in temperature. Food does not last nearly as long if it is frequently being brought up to 20 and then back down to 0...it does much better if it is brought up to 5 and then back down to 0, etc. For people who are only storing their food for a month the larger swings are ok, but if you are storing blueberries, meat etc for a long period of time like we are it helps to keep the temps from swinging so much.
-James

A friend who was off grid build his own chest refrigerator, using a 12 volt Danfoss compressor (the compressor and all related parts, evaporator, condenser, controls, etc., was available as a kit designed for home-bult units--I don't know if such a kit is still available) His unit also had a fan and duct to bring in outside air if it was colder outside than in his refrigerator, so for much of the year, the compressor didn't run at all, just a small fan ran occassionaly, as needed.