Repurpose a dead reefer as a root cellar

The new plan for a root cellar is to bury the old refrigerator that stopped working. I still need to modify it to take advantage of the chimney effect so that cool air will flow from the bottom and out through some sort of PVC pipe.

I got a kick out of your refrigerator burying idea, but wonder about the
cooling fluids, if there are any, and if there might be any chemicals you'd not want, seeping into any vegetables you might be storing?

--- Mom

That's a great question!  A century ago, the chemicals used to keep refrigerators cold included ammonia, methyl chloride, and sulfur dioxide, which leaked out of fridges and killed people.  As a result, we switched over to freon, a chemical that isn't toxic to humans but does rip big holes in the ozone layer if it escapes from your fridge.  In the 1990s, we switched again and started using a chemical that neither harms us nor the ozone layer.

Our fridge may date from the freon era, but since the fridge stopped cooling our food even though it kept running, we can be pretty sure that the refrigerants leaked out already.  The book we got the fridge root cellar idea out of suggested removing the cooling coils, but we think that we'd be more likely to puncture them and release refrigerants in the process.  Hopefully, any remaining refrigerant gases will be safely sequestered in the soil.

 

We decided to dig the refrigerator root cellar down a bit deeper to accommodate a large cinder block in each corner. I thought two post holes in the middle might help to increase the cold surface area that will hopefully stream a steady flow of cool air up through the refrigerator and out the soon to be installed vent pipe.

 

After thinking about lowering the refrigerator root cellar into our new hole I decided to see just how hard it would be to strip off the metal coil from the back of the unit. It turns out it only took about a half hour to take everything off including the compressor and wiring harness. I think it's going to make sliding down the hole a bit smoother and safer.

I'm planning on mounting some screen material over the new holes in the bottom. The good thing about this approach is that it will be easy to add more holes if we think the air flow needs to increase.

 

Two drill holes and a few minutes with the jig saw was all it took to create the new chimney hole for the refrigerator root cellar.

I also removed the foam and plastic barrier that separates the freezer from the rest of the refrigerator. One of the metal shelves slid right into its place, which will provide plenty of open space for the cool air to flow while at the same time working as a sturdy surface to store apples on.

 

It took both of us to lower the refrigerator root cellar into its new home below the earth. Once it was in place I decided to make some side panels from a couple of 2x4's and some scrap wood. It seems to be helping by keeping the dirt away from the hinge and door opening as I begin to bury it.

I was almost going to buy one of those heavy PVC caps for the refrigerator root cellar chimney, but when I walked past a foam faucet cover I stopped in my tracks, looked at the PVC cap in one hand and the foam cover on the shelf and weighed the coolness factor of the foam geometry along with the fact that it was only a buck compared to the 6 dollar price of the PVC.

Anna thinks it adds a sort of mother ship look to it and I agree.

The next step will be to drill some holes in the side towards the top of the chimney and then attach some screen material to keep out any unwanted bugs.

Temperature is the real test of a successful root cellar, with optimal temperatures from 32 F to 40 F, but with temperatures from 40 F to 50 F considered quite good.  I've seen quite a few fancy root cellars constructed with vast quantities of labor and cash which fail the simple temperature test.  Can our $10 root cellar do better?

We won't know for sure how our root cellar holds up until it has to deal with really hot days and really cold nights, but so far it's running great.  Over the last few days since Mark completed the fridge root cellar, it has held a semi-steady temperature between 40 F and 52 F.  I'll keep you updated on the temperature variations as the year progresses.

If you missed parts of the construction details, you might want to read back over our old entries (linked below), or watch the video here which sums it all up in a two and a half minute nutshell.  I hope that some of you are inspired to eschew the fancy root cellar craze and make your own root cellar for cheap.