Although I filled in the last missing pieces of insulation on the ceiling yesterday (2" R-13 board on top of R-30 fiberglass I’d installed several weeks ago), the temperature has not returned to where it was yesterday morning, and is well above where it was Tuesday, June 25, when I arrived and went in the room. I need the room to recover its cool temp faster.
Here’s an updated temp chart. The very sharp spikes around June 11 and yesterday are when I’ve been working in there and have been in and out through the door. Other smaller sharp upticks are quicker entries.
Despite R-34 (fiber batts plus close-cell board) on the basement-facing walls and R-43 on the ceiling, the temperature is still fluctuation significantly with outside temperatures – about one degree F over 24 hours if the door hasn’t opened. It rises starting around noon and continues rising until nearly midnight, then trends down for the next 12 hours or so. The culprit, I think, is the rest of the basement.
In addition to that diurnal variation, the average crept up in the week from June 18-25 when I wasn’t there as the weather (finally) became summerlike.
The next steps:
Cover the four basement windows. The rest of the basement was about 70F on Tuesday, but it’s been in the mid-80s and sunny most of the week, so that’s probably much higher now. Blocking the windows should bring down the basement temp significantly. I meant to do that yesterday before I left, but forgot.
Increase the insulation along the two foundation walls of the wine room. The interior of those walls was running from 58F to 60F this week, a degree or so higher than the basement-facing walls. I believe there is only only R-10 2" foam board behind the sheetrock (installed by the prior owner). The fact that the foundation-facing walls are slightly warmer than the others suggests the foundation is carrying heat down from outside and the insulation isn’t sufficient.
FYI, here’s a photo of the 2" R-Max R-13 board over the R-30 fiberglass on the ceiling.
I’d originally intended to cut the insulation board to fit the cavities between the studs and joists, but the studs weren’t perfectly square and the joists had warped, so the width of the cavities varied over the length of the joists/studs, making it all but impossible to size the boards tightly. My contractor suggested it would be easier, and provide better seal/insulation, to use batts and then put the board over the joists and studs, with sheetrock over it (still to come).
My ceiling is quite similar. Fiberglass, with board over it, and the joists. As I recall, we actually did two layers of fiberboard.
My daily temperature swings don’t seem to be quite a severe as yours, but the overall trend is the same…
(Like you, the spikes show time I was in the cellar.)
Thanks. That’s interesting. The upward temperature trend is quite similar, although your temps are lower – presumably because you’re in Maine.
What kind of R levels did you achieve? As I said above, I think the foundation wall insulation is probably inadequate in my place, but I think I may have reached the point of diminishing returns on the other surfaces.
Sorry if I’ve missed something, but have you thought about installing a cheap window Aircon for heatwaves and when the cellar creeps up to uncomfortably high temperatures? Just a few hundred bucks and no install costs. They can cap temperatures to the low 60s.
I had to go back and check my notes, but I think we got the ceiling to +/- R47, and the walls (both room facing, and outside facing) to R30, floor to ceiling. That was all then covered in plywood (and a poly vapor barrier behind it).
Gold’s suggestions on size of boxes worked very well for the way I wanted to store mine, so we used his suggested dimensions, which has generally worked well.
I’ve set a goal of making this completely passive, and such (sensible) suggestions are inconsistent with my obsessive desire to stay passive. And I think it should be possible, since the house is at 800"/250m elevation, so the nighttime temperatures are almost always moderate.
(There are also insulation issues using AC. Either you have to install and remove the machine, and have some high R-value plug for the slot, or construct something with a high R-value to encase the machine when it’s not used. The AC apparatus is likely to be the weak point in the insulation.)
One thing I notice here is that the backs of your shelves are enclosed. As I recall, Gold says that air flow up from the floor (and walls if they’re cool) is important, and he recommends setting your racking/shelves a few inches out from the wall to facilitate that.
I’ll be using metal shelving, with my wines in boxes, in part for that reason. It will be purely functional, not aesthetic.
Interesting John. I either missed that in the Gold book or chose to ignore it, I am not sure which! I would postulate that is less important than many/most of the other principals in his book, but I can’t argue that good air flow would be helpful, and mine does not really have that in mind.
Mine is purely functional as well. I priced out many different shelving options, and ultimately found it was not more expensive to have my builder build these, and get exactly what I wanted, exactly to Gold’s specs for max bulk storage, than to buy pre-made wire or wood racking. (YYMV!)
There is a flaw with them… The builder kept trying to convince me I wanted a different size, but I stuck to my guns, and am glad I did. Gold’s suggested dimensions are perfect.
BUT… If you notice on the top of each box, there is a piece of wood. (In the picture It kind of looks like a light colored square in the top corner of each box.) That is how the builder chose to build them. Good news: the support is excellent, and these will collapse under the heaviest weight. Bad news: that piece of wood changes the interior dimensions of the top rows, and in for some bottle sizes means I can only get 3 bottles in the top row, instead of 4.
Hardly a crisis! Just one of things you notice after you are done, that might have done differently.
This is a really great thread - thanks to all for commentary and pics.
I just ordered that Gold book.
I’ve got offsite underground storage right now, and I’d really like to get that back in my house.
I just have to figure out how to convince my SO that we don’t really need a linen closet any more and that my swill should replace all the towels, sheets etc.
Gold’s book is well worth the purchase, but please do take some of his experimentation and recommendations with a grain of salt. Some,of those experiments he did to prove a point were pretty biased or poorly controlled. But there is a lot of useful info in there.
I’m afraid his suggestion that you might need R-60 in this climate unless your foundation is on bedrock, and therefore very cold, looks like it may be borne out in my case.
Do you know what his background is/was? He used a PhD after his name, but his name is so common that I could never figure out what his day job was.
BTW, short-run fluctuations in air temperature aren’t that critical. It’s the liquid temperature that matters. My non-passive cellar varies in air temperature +/- 1.5 degrees but the liquid varies less than 10% of that. I think if you put in a liquid probe you’ll find the variation isn’t much even if it goes up and down 1-2 degrees during the day.
Yes, I realize that. And when I have all my wine in there, there will be a significant thermal mass, so the air temp will vary less. Nonetheless, I’m surprised by the fluctuation, given the R-43 on the ceiling and R-34 on the basement-facing walls. The foundation-facing walls may be underinsulated, but presumably the ground doesn’t vary much.
