I’ve just built my cellar room (minus racks) and was hoping to use it as a passive cellar based on the ground temperature data that has been posted in a previous thread. I live in northern Illinois and my the average ground temperature at 10 ft below grade in this area should be 51 degrees, with a yearly variation of +/- 7 degrees, based on the data posted in previous threads on passive cellars.
My cellar is 9 feet below grade, with 3 walls of the cellar as exterior walls, each covered by 9 feet of earth on their exterior side. The 4th wall is 8 inch thick concrete, facing our unfinished basement. The walls were insulated with 3 inches of closed cell spray foam and the ceiling was insulated with 4-6 inches of closed cell spray foam and then 6 inches of fiberglass batting insulation (total overkill, I know). The door is a heavy all weather insulated door.
Since construction has finished, I’ve kept a record of temps and humidity in the cellar and it stays at 61 degrees and 50-55% humidity. I’m stumped as to why the cellar won’t get any cooler unless the data I referenced above is wrong. I feel like I’m insulated well enough. I’m afraid I need to buy a cooling unit.
Justin, i dont have an answer to your question but i am very interested to hear what people say. I live very close to you and was thinking about doing almost the same exact thing knowing that i can keep it at 60-62 degrees without a cooling unit. So all thoughts people have on this question will be doubly appreciated.
That temperature is fine for long term storage. My passive cellar, that I have been using for 35 years, goes from 58 to 66 or even 68 sometimes in late summer. The temperature on the floor is a couple degrees cooler, so I keep the really expensive stuff near the floor along with the really long term stuff. You should be fine. If you get direct sunshine on any of he exterior walls, or on the ground adjacent, plant some low shrubs or something to ward off the warming effect of sunshine.
I use a passive cellar for my “daily drinkers”. Sometimes bottles can be in there for 2-3 years before I get around to drinking them. It ranges from 54 in the winter to 62 in the summer. The only problems I have had is with bottles that could tend to be bretty. A half case of chinon that I put in there started out fresh and crisp but ended up with each successive bottle being more and more bretty. Ditto with a half case of beaujolais. I assume it was the temps I was storing it at.
So I keep things like chinon and beaujolais in the Eurocave. Otherwise, the passive storage has been fine for my Italian daily drinkers, bargain burgundies, Cali chards and the like.
justin, I was just looking at the 2nd edition of the Gold book, and he only applied a little insulation to the exterior basement walls (plastic wrap plus thermax). The basement interior walls and the basement ceiling were treated with wrap, thermax and fiberglass. Do you think that you may have over insulated from your cooling source (the exterior walls), and therefore your average temperature will pretty much be the average temp in the basement?
Given your temps right now remember that a cooling unit will hardly ever run so it should last for years and keep the cellar at your desired temp year round.
Are you sure the ground temperature is really a steady 51 degrees? It may be at 9’ depth, but the ground slowly warms up in the summer, and just as slowly cools in the winter. My passive cellar cools below 55 degrees in the winter, and goes up to 65 in the summer, but lags the seasonal change in temperatures by several months.
Live in a similar climate and have never had any issues with a passive cellar. Temperature swings are gradual and I have had bottles for 20 years that have aged beautifully. Do make sure to stay away from furnaces and other appliances that will throw off heat and avoid exposure to sunlight and you will be fine. I know there is a school of thought that you have to consider humidity control, but I never have and never have had problems with corks drying out.
Wine is much less fragile than people give it credit. Just ask TomHill and his garagiste collection…
My passive cellar (built in a uninsullated concrete mechanic bay under my garage) ranges from low 40s (sometimes dipping into 30s in -20° nights before I put in small space heater) in the winter to upper 60s (and occasionally into 70s on 100°+ streaks) in summer. I have no qualms with those temps.
Don’t fret 61° at all. Put your money into wine rather than a cooling unit.
So wait. You encased all four concrete/cmu walls in insulation? What did you cover the insulation with?
My plan is to leave the north foundation wall as is or possibly tile it floor to ceiling. This is my major colling wall. The east wall is also half concrete and i will leave that and add a 2x4 r-13 greenboard wall. R-21 ceiling with greenboard and two r-13 2x4 walls with greenboard.
This sounds more like it. I don’t know where the original poster found that the temp “should be 51F”, because the number is not a static one, and I don’t know anyone who has a constant temperature unless they are really storing it below ground (as in a cave of some sort). But 61 sounds spot on this time of year with the warm weather in the East/Center and at your latitude. I think cellars that do not have windows may be cooler, and also take into consideration any heating unit or water heater that might be down there as well, because if that is turning on it could influence the base temp.
My passive cellar cools below 55 degrees in the winter, and goes up to 65 in the summer, but lags the seasonal change in temperatures by several months.
Yes, seasonal temperature variation depends on depth. The temperature changes 5 ft underground will lag surface temperatures by three months, 10 ft underground by four and a half months (and the variations are much smaller than at the surface). The room in your basement is a bit more complicated, because the door, internal wall, and probably ceiling are not as effective at insulating as 10 ft of dirt. But, 61F is pretty good and you can either use it as a passive cellar or add a modest amount of cooling.
My passive cellar in N. Michigan gets up to 65 for a short time in the summer then goes back down starting in September. Winter drops down to 50/51.
I wouldn’t worry about your cellar. When I lived in France, I was surprised to see rock caves carved into mountains at 65+. And, I drank 30 year old wines from those cellars that were fine.