I have a 20feet x 5feet long cold cellar under my concrete porch. All walls and floors are concrete. It is a new home. I have 2 4" holes on either end of the cellar. I will try your recommendation of the tubing from the outside holes to within 6" of the floor to maintain a more constant temperature. My question is if I insulate the walls, with the hardboard foam and seal the walls, will that not limit the humidity. Also, if I want to tile the floor, will that not reduce the humidity? My understanding is that the humidity should be very high.
Answer:
Insulating properly to a foot below exterior grade level will help keep down the humidity but none of the other measures will. What you store in there will probably be the best guide to humidity levels - fresh garden goods will go a long way toward raising it and the less of that you have in there, the lower willb e the humidity.
