Over the years, we’ve had several root cellars. We had a small refrigerator that we buried under the deck. There was the small earth covered root cellar out by the old garden. Then finally the root cellar in the Southeast corner of the basement. At first it was the old kitchen/bathroom turned storage room that I insulated. The insulation didn’t do much, so a couple of years ago I built a room within a room. I framed out a 3′ wide by 10′ long insulated portion along the Southern wall. I know, it’s not the best side, in fact it’s the worst side, but it was the only side. I added an air intake pipe and used the old vent pipe as the air outlet. It worked in the winter starting in December when the temperatures got cold enough, but it was only about 5 degrees colder than the temperature of the rest of the basement, and in the summer the temperature went up to 65.
This fall we were at the Urban Farm Fermentory in Portland and saw that in their cooler they used a gismo called a CoolBot to allow regular off the shelf air conditioners to be used as a refrigeration unit. So, I started to read the CoolBot website (what a helpful website and great company), and the lightbulb finally went on. The reason I could not get the root cellar cold enough was because I was fighting the below frost line temperature of the earth which is 52-54 degrees F. The earth is too warm to be a refrigerator! Now to explain, my idea of a root cellar has evolved. At first I just wanted to keep vegetables through the winter, but the more I got into charcuterie and the more eggs we got, I realized that a temperature of around 40 degrees F. is what I wanted.
So what I needed to do was insulate the cement wall and floor to keep the cold air from being sucked out by earth. The outside walls of the basement had 2″ blue board over the exposed cement, and the interior framed walls and ceiling were already insulated with 2″ foam. Unfortunately, a cooler is supposed to have 4″ of insulation. Week before last, apprentice Allan helped me puzzle piece more 2″ blue board between the shelves and pressure treat to cover the exposed cement wall.
We then used expanding foam to fill all gaps. The next day I put blue board on the floor and covered it with 11/16″ plywood. All I had to do was wait for my air conditioner and CoolBot to arrive. Saturday, while waiting for the maple syrup to come up to temp, I installed the air conditioner, a GE, one of the brands CooBot recommends, and the CoolBot. The air conditioner was a pain to install because of the cramped space, but the CoolBot was a snap. The instructions and trouble shooting guide are outstanding. The AC was running all the time, but the CB guide said that the fan ran all the time but not the cooling unit, and all I had to do was switch the cool setting to energy saver for the fan to not run all the time.
Now all I have to do is wait and see what kind of electricity it draws. The nice way it all evolved is that with the room within a room concept most of the leaked temperature will go into the outer storage room where we keep canned goods, hard cider, and wine. If I have any wisdom to impart with all of this, it’s if you ever build a house, design it around your heating system and your root cellar.