What is the best way to insulate a root cellar in the basement of a very “tight” new home?

We want a root cellar in the basement our new home. Throughout most of the year (except summer) the root cellar will have a temperature of 40-55 degrees F. and a humidity of 60-85%. Ventilation must be placed in the root cellar to keep air moving and keep the area cool--this is typically done with two PVC pipes sticking out of the foundation.

Our home will be very tight and ventilation will be controlled with a heat recovery ventilator. We are very concerned about high humidity levels causing mold problems in the walls and ceiling of the root cellar.

Specifications:

• The root cellar will be a 8x14 foot rectangle in the northeast corner.
  
• We plan to use insulated concrete forms (ICFs) for the basement foundation.
  
• The basement will be unfinished.
  

Questions:

• What is the best way to partition the root cellar off from the rest of the basement so its climate does not affect the rest of the home?
  
• What wall system should be used (SIPs?) and how should the walls be insulated?
  
• How should the ceiling be insulated?
  
• Does anything need to be done to the two exposed ICF walls?
  
• Is there a more modern way of ventilating the root cellar other than two PVC pipes sticking out of the foundation?
  

Thanks so much for your ideas and time.

-FMeyer

Why would you want to insulate the root cellar? The ones I've seen have earth walls and floors, and the one in particular that I know the most about extended out under an enclosed porch, which probably began life as a screened porch. There were no foundation walls at all.

If any of it extends much more than a foot above ground, it won't be a root cellar, it would simply be an extension of your basement.

We would like to place the root cellar in the corner of our basement; i.e., it would be a small room framed by two walls. Somehow this root cellar room needs to be partitioned off and insulated from the rest of the home so it will stay cold (and not make the rest of the house cold).

Perhaps there is another way to design it. Should we add a room off the basement that has an earthen floor and walls? A door through an ICF wall would provide access to that room. What are the pros and cons of this approach versus sectioning off a room in the basement. Would we have other worries: rodents, water, radon?

Why not section off a small area of the basement with wood stud construction, using 2x6 studs, with R-19 insulation in the stud cavities, and maybe an inch of rigid foam insulation across the face of the studs on the house side. Then use an insulated exterior door, fully weatherstripped, and insulate any heat or hot water piping that may exist within the space.

Oh, and insulate the ceiling within the room.