Converting a Chest Freezer Into a Very Efficient Refrigerator

Carl describes the simple conversion he did on his chest freezer to turn it into a very efficient refrigerator.   The conversion only costs $70, is very little work to do, and gets you a fridge that runs on less than $10 a year of electricity!


Thanks very much to Carl for sending this in!

More information of converting chest freezers into efficient refrigerators here...



This is the chest freezer converted into a refrigerator. 
The temperature sensor for the new external thermostat is visible at the bottom left.



I use an external thermostat to control the temperature in the old freezer.  I set the temperature at around 36F so that the freezer acts as a a refrigerator.  To do this, you plug controller into the wall, and plug the freezer into the controller, and then feed the copper sensor into freezer and lid just closes over it.  That's all there is to it!

The new thermostat turns off the freezer at your set point.  In my case, I set it to about 36 degrees, or 4 degrees above freezing.

In the 1st 24 hours of running the freezer as a refrigerator, it came in at 0.204 KWH, or 200 watt-hours for the full day!    The power use averages only 8.3 watts.  This works out to 73 KWH per year, amazing!!!!

< - It would be good to say something about the power usage over a longer period? >

It looks like one 75 watt solar panel would pretty much power it.

At 13 cents/KWH that's only  2.6 cents a day -- wow!  Times 30 days, that's 78 cents a month!  Or, a whopping $9.36 USD yearly, now that is cheap!!!!

So, I'm using twice as much as the celebrated 0.1 KWH per day the famous internet guy was using in his.

Still, I cant complain and this is a very preliminary result with day temps 85 degrees and night temps at 60 last night.  Inside temp 36.5 degrees towards the top.

Will do the weekly result when its a week.


< - Putting in the result for the week  would be good >

This is the Johnsons control unit, $65.00 delivered...


<- Not sure I got the place you actually got the thermostat from with the link above -- let me know where you got it if not  -- looks like it might be $70 now?>


Click on pictures for full size

The Johnson Controls ??? thermostat
Cost was $65 delivered.

Thermostat mounted next to the fridge.


<-- I'd be inclined to leave out the picture and material on the droplets unless you think its a problem?   But, easy to put in if you think its something that should b covered? >



Making Better Beer

With the thermostat control you can turn any freezer or refrigerator into a sophisticated lagering device and more accurately control the temperature of your ales. Simply place the temperature probe into the freezer, plug the thermostat into the outlet and then your freezer into the Control. This thermostat has a range from 30 degrees F to 80 degrees F.  Plus, with the purchase of this thermostat you receive a gift certificate worth 50% off the Learn To Brew's Recipe Formulation Made Easy Computer Program. This program will allow you to take creativity into your own hands and design beers just like the professionals.

  1. Easy to Install

  2. Easy Adjustment

  3. For Freezer or Refrigerator

< -- not clear on whether these 3 points have to do with the program above, or with using the thermostat above to help in beer making??  >

<- Is the 50% deal still going on? and, where is it?  >


Carl can be found on the Homesteading Today Forum in the Alternate Energy group.  He posts as MightyBooBoo, and would be glad to answer any questions on the conversion.


<- This is not that important, but any idea how much the original freezer consumed in power when operating as a freezer? >

Gary May 4, 2010