Thursday, October 8, 2009

Free Cold Weather Refrigeration

My husband is always thinking of new ways to become more self-sufficient. When he said “free refrigeration“, I was all ears; and ready for another project. Here’s his story:

In this off the grid homesteading life we live, there are a few issues that require a bit more attention than most, such as water pumping and refrigeration. Of those two, refrigeration is probably the most difficult to address, at least it has been for us. We have been using a propane refrigerator for the past few years (a solar one is just too expensive for us, and we are not sure if our system is large enough to handle one), but with the cost of propane on the rise we are trying to find an alternative.

We have managed to come up with a partial solution, at least for the cold months of the year. We got a small electric refrigerator someone was going to throw away because it stopped working. I have a friend who does appliance repair remove the gas from the compressor. Then I removed the compressor and the coils off the back of the unit. I left the thermostat in the refrigerator and found the two wires that control it on the back. These I left in place. Our mud room is on the north side of the house and from there you walk out into the woodshed. We cut a hole in the mudroom wall just big enough to fit the refrigerator into; the only part in the mudroom is the door and about an inch of the refrigerator. The rest is actually in the woodshed.

I made a shelf for the refrigerator to sit on because the woodshed is lower than the mudroom floor. I drilled a 4” hole down through the top of the refrigerator and put in a 4” diameter dust gate. A dust gate is a 4” round device with a sliding door so you can open or close the hole. I use them in my woodworking shop for sawdust control. I took a 4” 90o PVC elbow and mounted a 3 ½” muffin fan (computers use these, so they are easy to find and not expensive, plus they run off 12 volts) inside the elbow. I drilled a small hole in the elbow to run the fan wires through. One wire connects to one of the wires in the thermostat inside the refrigerator; the other connects to the positive side of our battery bank (which happens to be in the same room). The second wire on the thermostat connects to the negative side of the battery bank. This enables the thermostat to control the fan. When the fan is on, it pulls cold air in from the outdoors. With the elbow in place, I then cut a hole through the outside wall of the woodshed and ran a section of 4” PVC pipe from the elbow to the outside. The pipe extends about 4” past the wall. I put a piece of aluminum window screen over the end of the pipe and then slid a 22o elbow over the end. This holds the screen in place and keeps bugs etc from entering the pipe (all pipe is schedule 20).

Once everything was put together and tested, I sealed around the refrigerator with insulation and added trim.

By the end of October or so we are able to move our food to this refrigerator and can turn off the gas one. Last year we had a cool spring and didn’t have to start using the propane refrigerator until mid April….almost 6 months of free refrigeration!

Winter refrigerator, inside house, before finish work.
Winter Refrigerator

Vent pipe (with fan inside) on top of the refrigerator(black flat part at the bottom is the dust gate).
Vent From Top Of Refrigerator