Convert Freezer to Fridge

The first thing any off-gridder will tell you when asked what’s involved in going off grid is “Reduce your power needs!!”. (Unless they think you are inherently lazy or a pussy, then the best advice they could offer would be “Don’t bother”.) Part of our power strategy was to convert a small chest freezer to a refrigerator. It it’s a great way to reduce our power consumption. Our old fridge consumed about 0.8 kWh per day. Not bad when compared to most fridges out there. The new setup consumes about 0.15 kWh day. Pretty substantial power savings for our small(ish) off-grid home setup. The way we accomplished the conversion was pretty simple, buy a temperature controller. Nothing has to be modified on the freezer itself. Stick a temperature probe inside the freezer, plug it into the controller, then plug the controller into the wall. Set the desired temperature and you are done.

The first controller I bought was designed and built by another off-gridder from scratch. Pretty cool, the guy even makes his own printed circuit boards in his units. But my early production unit just didn’t last, and started screwing up. It would click a bunch of times and then set the ‘desired’ temperature to 0 degrees. That means frozen food in the ‘fridge’. Not good. Worse than the frozen eggs and milk and the long unscheduled drive to town is ‘that look’ that I mentioned in a previous post.

So I picked up a couple STC 1000 controllers for about $35 each. One for the fridge and one for the freezer. These require a bit of wiring, but nothing too difficult. A good video on the web shows how to wire it properly in great detail. ( Note that these units can trigger both cooling and heating devices with one controller. I’m only interested in cooling for my purposes, so my wiring ended up simplified a bit. If they work out well, I’ll definitely get another when it’s time to get into chickens and an incubator.


Yep, that’s calfskin on the floor. It feels awesome on bare feet. So soft, warm and smooth. It’s like walking on babies.

6 thoughts on “Convert Freezer to Fridge”

  1. Ok, I dont recognize that controler and am wondering why it needs a fan? That makes me think its not optimal, maybe solid state (Sinclair supply sells a great mechanical one)…measurement is very important, did you get that off a P4 killowatt meter (tell ,me you have one) or what else are you using to measure this. I never got a frezzer below 190-200 whrs thats why I stuck with my fridge at 244 whrs, you may have yours in a cooler place than my testing was done, or maybe its a newer model, my testing of this stoped back in 2006 or so….Measurement is so important, you will find this hard to believe but not all energuide ratings are accurate, same with name plate specs….I was caught by this back around 2005 when I suggested a Danby model frezzer from Home Depot to a couple off grid people based on just the energuide ratings, I wired up the controls, tested the units and dialed in the temp gauge to a tight steady 34 F. Took a couple days to dial it in, as It was in my garage running on grid power I didnt put my killowatt meter on it (was sloppy) anyway they picked them up and next day im called to check them out as their batts were being hammered….In checking out what was wrong I found that right out of the box they used 3X mybe 3.5Xthe energuide ratting… I wont be caught like that again…now its trust but verified…..always. If I forgot to mention it there is a product called a killowat meter, I use a p4 series…displays amps/whrs/voltage/ freq/ VA/time, it does all the math for you…maybe 40 bucks or so..

    just remembered I caught a bunch of LED bulbs that used twice the power claimed with one of these, … but verified..always

  2. I get up with those numbers still in my head…takes me a half hour to find my notes and double check…I goofed my converted frezzer compartment in the fridge is 266 whrs/day (5.5cuft) 244 was from a 6 cuft stand alone frezzer I tested as a fridge once..My memory is bad will check my notes first before posting numbers…at 150 whrs your almost half my consumption

  3. Hi Analog Man,
    You had me going there about the fan. I scoured the google trying to find out what was inside the controller for a fan. Almost was going to bust one open to see what was inside. Those orange things on the side are mounting brackets.
    More importantly though, I am also guilty of posting numbers from memory. I do have a kill-a-watt (branded ‘Blue Planet’) so I will have to double check my numbers. My meter is in a box somewhere though and I’m going to have to go on a scavenger hunt for it. I will post the correct numbers when I get them. Probably in a day or two. Today is all about cutting up pallets for the blazeking. BTW, I am very happy with the blazeking, Thank you for the recommendation on that!

  4. Your blue planet one is likely the same as mine..So handy you can plug one into your generator to check engine rpm’s (by way of freq), then confirm alternator output by voltage…handy to diagnose generator problems..or recording kwhs of charge into your batts…When/if you post your fridge measuements could you humor me and do a test of your microwave, not with the killowatt meter but rather the DC amp draw of your batts, just put a glass of water in the mic, set it to 3 power level hit start and write down the DC amp draw, then do this at power level 5,7, and 9. Maybe write down your batt voltage at these power levels if you dont mind, and you only have to let it run for a couple seconds at each setting to get a reading…and on a day when your batts are fully charged ofcourse

    1. My updated fridge numbers are coming in my next post. As for the microwave numbers, I’m sorry, can’t help out. Don’t have a microwave anymore. It freaked out one day in our grid house and actually started running by itself! Good thing we were there when it happened or things could have turned out quite bad. We do have a small induction cooker though that we have not used yet. I will post the numbers that I see for that, like how long and how many watts to boil a litre of water, etc.

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