Overall, I am very pleased with the root cellar I built last spring. It’s keeping temperature well, not showing signs of mold or infestation, and most of the produce is in very good shape. I have learned a few things and made some changes from the original design, though, and I’ve got some good preliminary data on which arrangement of bins is working best for me.
First, I had to take the paneling off the outside of the cellar before I even put food in it. This was pressed-wood-fiber type paneling, got cheap at the re-use center. It was pretty, but even though I took great pains to keep it from touching the floor or walls, it started absorbing moisture and got very moldy very fast. I pulled it off and didn’t replace it with anything, so the outside wall of the cellar is bare studs and you can see through to the rigid foam insulation. While my aesthetic side is sad, it doesn’t change the functionality at all, and I really want to avoid starting a mold farm in the basement.
Second, I’ve abandoned the complicated ventilation system. It wasn’t letting the cellar cool down enough in the early fall – we’d have a 35 degree night and the temp would only drop from 60 to 58. Not nearly good enough. I ended up just opening and closing the window as needed. That worked really well until about mid-December. Then I got to a point where having the window open was too cold but leaving it closed was too warm. (The cellar holds around 40 with no ventilation.) So I took the window out completely and put the board back into the window. (There’s a screen to keep critters out.) This board is about 4″ narrower than the window frame (it had held the vent pipes in place) so it effectively closes off 85% of the window but left it open a bit for some air to get in and out. I can leave it like that night and day unless we have a series of lows near zero and highs below 15F – then I need to put the window back in or it gets too cold in the cellar.
This hasn’t been much trouble at all. I have a thermometer with a remote sensor on the kitchen counter, so I can see the temp in the root cellar many times a day as I’m passing by. This has let me learn its patterns. For example, I now know that if it’s going to be cold many days in a row, I need to close the window up completely. It’s a 5-minute chore to open the window, or to swap the window and the ventilated board, so no big deal there.
Third, humidity. I can’t seem to get the humidity in the room to stay above 50% now that winter has set in, even with bins of damp sand on the floor, so instead I’m trying to keep the local humidity around the produce high. I’m ok with this – it seems to be working fine, except maybe for beets, and I’ve definitely not had trouble with mold on the walls. My only concern is that the methods I describe below won’t keep things moist for the whole winter. I’ll report back in April on that one.
The information on the bins is quite extensive – I’ll post that separately tomorrow.