Anyone building this type of cellar would be well served by getting Richard Gold's book on the subject. Also cork flooring is a very good option in the cellar. Cheers

Springtime homes - I really really appreciate your feedback, however you are not entirely correct. I have been reading up on how to set this up and the upper 1/3 to 1/2 of the foundation needs to be insulated to prevent heat transferring from the upper parts of the soil and the exterior foundation. Unfortunately we are forced to either have this at the west or east side of the foundation (one wall) so that creates additional difficulties. It is the bottom portion of the wall and the floor itself that keeps the room cool. The room itself will be close to air tight due to a vapor barrier and a well insulated exterior door entering the room. The walls shared with the house and the ceiling will be VERY will insulated, to the highest R value that we can fit into the space! :) I'm really curious if there is anyone on GardenWeb who has built a passive wine cellar themselves and if they have any specific tips beyond what is standard. There are 3 main questions I have as well. 1. For instance. I wonder if there is a way to separate the concrete floor from the rest of the basement while the foundation is being laid so that there is not any heat transfer through the concrete in the rest of the basement? 2. If one (or two) of the exterior walls are completely under the house and not shared the the rest of the homes foundation, then would their be any difference in how you insulate the concrete from the exterior? 3. And, should I plan for two or three exterior walls? The problem with planning three is that it would make it very difficult to then add a cooling system if this didn't end up working.

The wine storage will be cooler. If the area outside of the wine storage will not be high humidity, you don't need a vapor barrier. You want to stop air flow and insulate. Fiber bats will not stop air leaks. Spray foam will.

You are going to have a lot of problems. You're sealing the concrete wall with the insulation? "I started with 1 layer of the 4” XPS over the ceiling and then covered all the walls with 1 layer of 4” XPS foam leaving 1’ of bare concrete at the floor on the exterior North and East walls)." What's on the other side of the concrete? Dirt? Or is it an attached house like a row house? If it's a detached house and it's just dirt on the other side, which seems to be the case because you said it extends 7 ft below grade, you will have a great deal of condensation and eventually mold. The concrete walls are not completely dry and sealing them the way you did allows no place for the moisture to go. Don't seal those walls off. "As for venting, no. It is a fully inclosed concrete box. Monitored humidity is a constant 70%." So the ceiling is concrete too and your entry stairs are over that? If so, no wonder you have condensation. On the other hand, you have the makings of a great wine cellar. I wish I had that. Depending on where you are, the soil temperature can vary quite a bit between winter and summer but you're in a cool area so you should be fine. If you have 70 percent humidity in the concrete room, why are you insulating with a vapor-proof material and then sealing off all possible avenues for the moisture to escape? You can't do that. What happens to the temperatures if you don't seal the ceiling and concrete walls and just insulate the walls exposed to the basement? I think you'd be far better off with that approach. If the concrete walls give you a stable temp, why insulate them? Also - the door is R10 and the rest of the insulation is R20? If you really want R20, put insulation on the door too. Otherwise, you have a huge section of your wall that has a lower R value than everything else and you will effectively have insulation of R10. To start, I would take down the insulation from the concrete and monitor the resulting temp in the room. It seems like you can actually get a pretty good temperature and perfect humidity with what you have, doing minimal work. Good luck.