I don’t know the answer to your specific question. But what about building passive but with space in the framing to add a through-the-wall cooling unit if you need it? They fit in standard width framing, and you just need to add cross pieces to support the unit. You can include that for the cost of a couple of pieces of 2x4 and cover it over. Then if you need to add cooling you can cut out the wallboard and add a unit.
Don’t forget to have electricity nearby in case you add cooling.
I’m talking about ac ducting. You can open them to the basement
Oh I see. Yes, I do have the ducting. I was under the impression that normal AC doesn’t get cold enough for a wine cellar? I thought the wine cellar units were specialized units?
It’s not “cellar cool” but it helps moderate the temperatures.
Depends on your AC.
If you use the ducts for your home, you will never get cool enough because nobody wants to hang out at that temp. If you have a dedicated unit however, you can drop the temp.
In your case, what I would do is put a bottle of water on the floor and take that temp. Your floor may not be the temp of the space just above and you want to know how cool your wine will be, not the floor. If you can just block off some area with some kind of barrier and put a little box or shelf in there, put another bottle higher up off the floor and take that temp too.
Sounds like you’re hoping that the floor will cool the room, or take in enough heat, to suffice for the entire room. It may but it won’t keep your wine at 56F. If you can keep it in the 60s through the summer, you will be OK. There are many many passive cellars in Europe that have that kind of temp. When they dig into the mountain, like they do all over Hungary, you get much cooler, damper places and mold grows on your bottles, so they wrap them in plastic. But you won’t get that cold or wet in your basement.
The second bit you can think about is that even a large cellar will probably be adequately cooled by a very small window AC that you can get for $90 at Lowes or Home Depot. Some of those will actually go down to 61F or so, and if you build that into a wall, you can use it in July and August and rely on the passive cooling the rest of the time. And it can serve as your fan as well. The unit will be oversized for your cellar, which means it will cycle off quickly and won’t drop the humidity like it’s supposed to for your bedroom, and that is exactly what you want for your cellar.
There are ways to trick the AC unit to get colder, but it’s not necessary. Just get one that goes way down and keep it at the lowest setting. I kept wine for over 10 years with that little setup and the wine is still fine. We had a 1992 Dunn the other day and it was stellar. I just vented it into the rest of the basement. It was never a problem because as I said, it’s not running most of the time.
People worry WAY too much about humidity. That is the least important issue for you - the wine in the bottles will ensure that the headspace humidity is adequate. And wine does not escape through the cork if you don’t put the bottles on their sides. You put them on their sides because it’s more efficient to store them that way.
Vapor barriers have their own mythology around here.
What causes vapor?
You get vapor when you have something cold enough to reach the dew point of the other side of the container. You take a Coke from the fridge and set it on the counter and you get condensation. In a passive cellar, how would you get such a gradient? Even if you insulate the cellar the rest of the space is still that same basement. If you built the cellar in the attic where the temp is 110F and you cooled the cellar to 50F, you would want a lot of insulation and probably a vapor barrier. But if you’re talking 60F inside and 65F outside, you won’t get vapor, especially if you insulate reasonably well. I used no vapor barrier at all. But just in case, I used Wonderboard, not drywall. Drywall is never vapor proof - the green stuff is the same as the other stuff. And while Wonderboard doesn’t look all that great with the bubble holes. it’s not going to be visible since you’ll have wine in the cellar. So who cares? In fact, the cellar is just a closet, so who cares what it looks like inside? I never understood tricking them out with special lighting and expensive racks, but to each his own.
BTW - the wine cellar units are NOT specialized units. All refrigerators, air conditioners, and wine cellars work on the exact same principle - condense a gas into a liquid, move it into another location and let it suddenly turn back into a gas, and then repeat. You add heat on one side and absorb heat on the other side. For super-suckers however, they do produce wine fridges with dual zones, one for whites and one for reds. I can’t believe anyone would ever buy one, but when it comes to wine, myth trumps reality. Kind of like many things in life.
Good luck.
Do you have the cellar set up as its own zone? And if so, what do you set the temperature to? If not set up as its own zone, how do you have it set up to do that?
I’ll check into it. My build will be strictly utilitarian storage. Double deep racking on 3 walls with hopefully a bit of space on top of the racks for bins to fit oversized bottles.
I do not. I just control the home AC using my nest thermostat to keep the cellar temperature in the range I want.
Judging by my experience with a passive cellar in the Hudson Valley, and your current basement temp of 65F, I think you’ll be fine if you’re comfortable with wine cellar temps in the mid-60s for a couple of months. Central New Hampshire is substantially cooler all year round than where I am, which will help a lot.
My wine room ranges from very high 40Fs in winter to ~66/67F in July and August. That’s with two heavily insulated exterior walls that are maybe 2 feet above ground, and two heavily insulated walls facing the open basement. The ceiling and interior walls I got to something like R50, which was kind of overkill.
The rest of the basement gets into the high 70s by mid-summer, and some of that is transmitted through the concrete floor to the wine room, but the floor there stays in the mid-50s, and it’s the most important cooling surface. The insulated interior walls get to the high 50s, as do the exterior walls.
I don’t believer that measuring your current floor temp before you enclose and insulate the space will be a good guide, because the floor will reflect the basement air temp. Once you’ve sealed off the wine area, the floor in that space will be much cooler.
I haven’t thought to use a fan. But I keep my wine in cardboard boxes, so the wine is less exposed to temperature fluctuations, and I used metal industrial shelving, so there is nothing directly on the floor, which would serve as an unwanted insulator. A little convection would probably help, provided that the fan is very efficient and generates little heat. I’d be a little nervous about heat buildup from a fan in an sealed environment, though.
As for vapor barriers, I think you will need one because you’ll have have a big differential in temperatures in both winter (cold outside, moderate inside) and summer (cool in cellar, warm in the rest of the basement), so there’s a risk of condensation.
If you are basing this on the circled average air temp of 47.2, that isn’t the number you are concerned about. It is the hottest temperature and for how long. There are sources for soil temps at depth where you live. You don’t say how far below the soil surface the basement is, how many walls are against the soil, or if any of the wall surface area is above ground. Assuming a standard cellar depth, you should be fine with passive in NH unless you are planning to keep high-end wine for 15+ years.
I built a passive cellar here in the eastern panhandle of WV 10 years ago by framing in a basement corner (2 walls against the soil, all below grade). My air temps range from 55-60 in the winter and then hit a high usually in August-early September of 68 for a couple of weeks, may hit 70 for a couple of days in there. I’m fine with that and don’t bother with the thermometer in a bottle thing, since the actual bottle temps are likely less than air. I do have a Eurocave for longer cellaring of Bordeaux, port, Rioja’s, etc.
We have been in the upper 80’s/low 90’s for weeks now. Basement floor is 62.3. That’s good enough for me. If I was trying to hold things for 50 yrs, I may buy a unit, but the 2000 Prieure Lichine I opened a month ago was in perfectly fine shape. Same with several recent 2008 St Innocent bottles.
What’s the air temp? My guess is that it’s somewhat higher.
That was the air temp about 3 inches off the ground. It’s about a degree higher at 4-5 ft.
I have some double deep cabinets that I built that are 3 ft high, wrapped in plywood, but open to the basement floor which seems to keep the cooler floor temps within.
My multi level house has an unheated below grade 750 sq ft mechanical/ storage level. The cool air from the air conditioning that gets under the basement door gets trapped down there. The center of the room air temp is around 63.5-64 degrees at 4 ft.
If you have AC ducts in basement, that certainly can help. Remember if you have your AC set for 72, system isn’t blowing 72 degree air . Intake/output differential should be 15-20 degrees. In an insulated room would matter.
One factor that will affect your cooling decisions are your plans for wine - what kind and are you looking at short or long holding times. A passive cellar that never gets above 65 F. is ideal as long as you aren’t trying to keep wines for 25 years plus.
OTOH, if you add up the value of the wines you have/will have, and the total is fairly high (it often is) and you do plan on a long hold for some, a cooling unit is advisable. I run my cellar at 13 C. which is 55 F., which I consider ideal for long holding, but the proper sized cellar unit will be somewhat expensive. I use a Whisperkool 8000 (I think they are around $6K these days) and they will do a fairly large room (mine is a 14’x15’).
If you can go passive, by all means go for it, but bear in mind what we have been seeing in weather trends lately - lots of long heat waves, forest fires etc. may indicate that having reserve cooling is a good idea.
i am curious how many wine producers are considering switching to active cooling as a result of more frequent heat waves. generally old world cellars are not quite as cool as we suspect but i have been in some that were noticeably tepid recently.
Many wineries already use tanks with cooling jackets
i was speaking mostly of the conditions they store their library bottles in as that is most relevant to the conversation here.
I live in PA and have a vented duct from the house AC that opens into the space. In the summer it never gets warmer than 60. Cold air in the house sinks so it pools in the basement anyway. I never worried about a vapor barrier, don’t have a damp basement and the humidity stays about 70%. If you have a damp basement might be more of a concern.
