by kjmclark » Fri 09 Mar 2007, 23:40:47
The book "Root Cellaring" by Mike and Nancy Bubel is excellent. It covers various forms of root cellars, what crops do well in root cellars, how to store the crops, things to look out for, etc. We sealed off a portion of our basement pantry, insulated some of the walls (not the concrete walls), and put in two six inch ducts. One duct goes from the north-facing back yard to the bottom of the root cellar. The other goes from the top of the root cellar to the unheated garage. I put a damper in the input duct and duct fans in both ducts. I connected the duct fans to a cheap thermostat and to an old solid-state switch I bought years ago. It's funny, I only found one programmable thermostat that would go down to 35F and it was a cheap one.
For November and December, I had the thermostat and fans on a timer to turn on at night if the temperature wasn't low enough. About mid-January it got down to 40F, which was cold enough for our purposes, and I unplugged the fans. I had to close the intake duct in February, when it finally got cold here. Since three sides of the root cellar are concrete, I expect it to stay cold for a while into the spring.
The room that the root cellar is in also got cool, which is fine, since it's our pantry and my work room. I re-sealed the door into the room and now that room stays around 50F, which is great for our remaining squash, and we can heat up the rest of the basement when we want. We lost a few squash before we realized the root cellar was too cold for them, but we haven't lost any of our potatoes or onions in the root cellar. I still miss all of the Bok Choy that rotted because I kept them too enclosed in a too-warm root cellar.