My wife and I live in a house with a wine “cellar”, but it’s really just a beautiful room with racking and lined with wood. There’s no insulation, moisture barrier, or cooling. Currently the room stays at about 65-67 year round; one wall is an exterior wall, below grade, and the other two walls have a guest room and closet on the other side.
I’m considering DIYing the build with a through the wall unit venting into the guest room (easily 4x the size of the cellar). Due to having access to two of the cellar walls from the other side of the wall I was considering closed cell spray-foaming from the guest room and closet so I don’t have to take down racking and it seems like it would be an easier drywall repair. Am I crazy?
I’d still need to insulate the ceiling from inside the cellar, but I figured I wouldn’t bother with the exterior wall since there’s already strayed-in insulation and this would limit the tear-down and rebuild.
Working with closed-foam spray insulation requires very special expertise, because of toxicity before curing.
Also, if you have heat pumping into the guest room during summer, your guests may choose to sleep with the wines.
You need professionals to spray closed-cell foam. They use haz-mat suits.
It sounds like the differential between the guest room and the wine room won’t be that great, so you may not need a huge amount of insulation. Standard fiberglas batts for 2x4 wall cavities are R-21. Those are easy to install. You’d need a vapor barrier, too, of course.
Alternatively, you could get a little higher R-value (~23) using polyisocyanurate foam insulation boards (a 2" board @ R-13 together with a 1.5" board @ R-10 will fit in the 2x4 cavity). They come foiled, so if you fit them tightly and use open-cell spray foam around any cracks at the edges, they form a vapor barrier. However (as I learned), if your studs aren’t perfectly straight, it becomes nearly impossible to cut the boards in a way that won’t leave some cracks.
Thanks for the feedback. Sounds like going into the backside isn’t much of an issue.
I live in southeastern Ohio. Humidity in the house currently is 72%, but it gets down to 30-40% humidity in the winter.
Fiberglass batts sound nice on the install, I just wasn’t sure if installing the vapor barrier over it (in this case) then drywalling would be an issue.
You need the vapor barrier against the colder surface, right? I’m not sure, but you might have problems putting the barrier on over the fiberglass – i.e., at the warmer surface.
Rajesh, you are going to have to make some tough decisions about what all you want to tear out and keep. A couple things that I can suggest which would work within your current plans. Generally you should have a vapor barrier for everything, walls, ceilings and flooring, including your door that can have a rubberized bottom attachment. A good way to vapor barrier the floor if its concrete is to use a special rubberized paint on vapor barrier that smells real awful as it’s high voc, so you need to ventilate when you apply it, but that seals your floor amazingly well. You can then lay some marble, granite, or onyx, or a combination of types of tiles on your floor. (If it’s not level, you would need to level it and have the concrete cure long enough prior to vapor sealing the floor) I don’t recommend normal dry wall for wine cellars, even if it is the purple type or a high humidity type. Dry wall can still get mold eventually. And, so can wood but it looks so pretty. I recommend fiberglass panels with mold resistant paint as this used in hospital walls to try to achieve a sterile environment. I would use something like this product, Densamorplus, which also is fire resistant.
You are also going to need to figure out how you are going to have your units drip line distribute the condensation outside of the cellar. Often that can be combined with internal air conditioning unit drainage.
Lastly, I did exactly what you did when I built my own walk in cellar, and vented into another room. If the room is a decent enough sized room, the air discharge should not be that much of a problem. However, the best way to do it (which I did not do, but will probably alter in a year as I have too damn many construction projects on my plate) is to vent the discharged hot air to outside of your home. Possibly using a flexible hose type venting, or pvc piping. There could be a vent valve on the exterior of the home if you want to, or vent out with just a screen at the end of the venting.
If you want to talk, I can talk when we both have free time.
If you are trying to find the path of least resistance and have easy access to two of the walls without having to remove racking, installing batt insulation would be adequate and provide enough R-Value to meet recommended specs for in wall chilling units (which I think specify results in R-15 or higher). Modern batt insulation has a built in vapor barrier (the paper side) that you would need installing facing the heated side (presumably facing opposite the cellar). For the other walls and ceiling, you could use a rigid insulation which is fairly easy to install yourself and is also its own vapor barrier. The rigid gives you R-5 for every inch applied and you can paint directly on it or attach wood paneling.
Regarding the floor, is it concrete? They make a dry lock paint for concrete slab that is easy to use and looks fairly nice when applied. I just finished my cellar built using it and rigid insulation which I just painted white. I also have a bucket of water and towel to increase moisture in the room. It isn’t anything special, but it gets the job done.
I did the same as you, rigid insulation and just painted it white, with insulation tape between the seams. I didn’t tape the seams in the ceiling and left the concrete floor as it - I had read that you needed to have somewhere for the moisture to escape, since it inevitably would build up?
Either way, I haven’t had any condensation or moisture issues in the 2 months since I finished.
@rajesh - in terms of ease of installation, I think your biggest issue is what to do with the drip line? Mine just runs into a bucket, but its in an unfinished basement.
Yea, my moisture has been fine in the room before I did this when it was cinder block and now that it is finished months later. Relative humidity was over 50% before I added the water to the room and after it bumps it up to the 70’s. I have a aprilaire permanent dehumidifier in my basement for purposes of keeping mold down, so adding some extra moisture in the cellar helped get the room to a more desirable relative humidity.
Nice idea on the taping of the seems, I ended up painting the first layer with a this primer/sealer and whatever gaps didn’t get filled, I applied ready patch to fill in everything else. I didn’t bother sanding it or trying to smooth it at all, the bright white paint barely shows anything and it is a cellar after all.
Regarding the drip line, could always drop it in to a sump pump if there is one available. It would be ideal to dump it outside, but the sump pump route will work.
One can get DIY kits. But it is messy - really messy. You will probably conclude afterwards it would have been better to move the wine out and confine the mess to a closed, unfinished space rather than move everything out of the guest room and have to deal with cleaning it up.
Also, put aside the heat of a cooling unit, the noise in a guest room at night may be more than your guests will want to deal with.
Joe - Originally I had a budget of 10-15k in mind for the project and was going to hire a contractor. As with all construction right now, the highly recommended ones wouldn’t even return my emails and the two the came out to quote didn’t give me a lot of confidence.
I should have mentioned that the concrete floor is already sealed, the whole basement/house is contemporary, concrete floors.
You’ll find that there is a lot of disagreement on how important humidity actually is. Some of us don’t think it’s important at all (within reason, as long as you’re not in the high desert at 10%). At 50% nominal, I wouldn’t be concerned at all about adding extra. Which brings me to my second point: you might be able to just collect the small amount of condensation you would get in a drip pan, and empty that manually every once in a while if it needs it. Would serve the purpose of recycling back into the room anyway, if you consider that important. Given how little the AC would probably run at your ambient temperature, you won’t get that much condensation.
Alan, agreed, especially on the alternative of bringing the condensate line back in to the room. The humidity figures I mention were for summer, winter is much drier so the wick and water bucket help (I am in Northern NJ). I am currently running a passive cellar also, temps in summer stay below 70 since the room is below grade and insulated. Off summer months and in winter the temp hovers around 55. I usually drink most wine with 5-10 years of release, so I don’t get too worked up about the 60 degree temps in the summer.
If I ever decide to get more precise for the cellar, I future proofed things a bit and added electrical access if I need to install a chiller. My wife and I are expecting our first child, so I am more focused on getting things set up for that.
Not sure the size of the room you are working with, but 10-15K sounds like a healthy budget to get things insulated. Although I would think it would be cheaper to hire a handyman/contractor and give them specific instructions on what R-Values you want to achieve and what your trying to accomplish. Around here, there is a hefty premium to hire a wine cellar installer to do the work.
The HVAC guy that I used for my other home renovations had experience installing chiller units as well, and it was much cheaper then the quotes I received from the “wine cellar experts.”
