I have a client who owns a liquor store. We are going to add a three story addition on the back for warehouse space with a roof party deck. Bottom floor will be slightly below grade with masonry walls, upper two floors will be structural steel with stucco exterior. HVAC units on roof. This is in Las Cruces, NM desert.
The owner now has decided he wants to build a wine cave at the lowest level, preferably with natural 85% humidity and 59 degrees to rent space for customers to store and age wine. I think he needs at a minimum to have mech systems as a backup.
The architect asked me for ideas about thermal mass storage, etc. and how deep we would need to go. I don’t think we can get the humidity naturally. He thinks we can lower a thermometer into a test hole bored for soil analysis, but I am skeptical…any ideas?
Nick Andrews
“They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety.”- Benjamin Franklin, Historical Review of Pennsylvania, 1759
Replies
Not likely. Especially in a desert. Near me, there is a deep limestone mine no longer in operation as a mine, but as a storage facility. You can store stuff in the mine which is a relatively constant temp, but if you want constant 65° and 65% rh, you have to pay more because they have to condition the air. I tried to call and ask what the normal temp in the mine is, but got vm. You might give them a call and ask. Here's a url:
http://www.bradysbend.com/
Coal mines around here run about 50-60°, but vary a bit by season. They get to be several hundred feet deep. No matter what, if you want constant rh/temps, you'll need to condition somewhat. As for how deep, a local mining engineer could probably give you the answer off the top of his head -- a lot easier than drilling or digging a test hole. My guess is that "slightly below grade" ain't gonna cut it.
Mike Hennessy
Pittsburgh, PA
That's what I told the architect. If we were down in valley closer to the Rio Grande, RH would be naturally higher. But up in the sand where the building is, no way. I figured temp would be easier to get naturally than the RH.Nick Andrews"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety."- Benjamin Franklin, Historical Review of Pennsylvania, 1759
Definately do the bore hole and temp and moisture levels.
Until you know what you have naturally, you won't know what to suplement.
A set of Drain tiles running from bottom of wall into the backfill up to the tops of walls might work.
High lime 'crete walls, thickened for strength might work. Maybe a post and beam load carrying system with porous infills.
You might have to use a soil moisture meter and maintain moisture levels in the backfill.
At some depth you may find a constant <= 59*.
Your client just has to remember, the closer to perfect the more $$$.
There is also the economy of scale. Let's say 40" aisles, basic unit of storage is 2'wide, 16" deep, from 18" EL to 78" EL tall. 10 sqft of wall space or 40 bottles. 1/2 the aisle + storage depth x 2'wide = 6sqft of floor. Say that on average each client stores 120 bottles, that require 18 sqft of floor for each client. That works out to about 2000sqft per 100 clients. With just 250 clients, that's a 70'x70' space.
You may want to break that up into smaller chunks separated by 8' - 10' backfill so the moisture infiltration and ground cooling can be maximised. Imagine a checker board, now expand the black squares so they overlap a bit and fill the red squares with soil. Or a honeycomb, shrinking the soil filled cells, that might give maximum soil contact and wall space per sqft of structure.
I would recommend at least 6' of overburden and I would use that above ground area for a garden or park so as to maintain soil moisture levels. Add shading and it will tend to keep the ground cooler.
SamT
I've built a few " wine caves", all I can do is give you my thoughts. Built them all out of solid concrete, handles the mass question well, 12 inch walls and 10 inch ceilings and floors. Isolated from the floors abovew/ 2 inch foam. ante-chamber at bottom of stairs leading to cave. Ante-chamber, walls of cave,entry to cave door jamb area all brick. brick paver floors. floor drains in cave- hooked to a sump pump located behind small door in ante-chamber. missed arch top door to cave. fiberglass door and jamb to prevent rust. most likely need back-up temp and humidity control in the desert. Had one where there was a moisture "problem" when I went back at bout 2 years to see how it worked. Thinkin to myself, how in the heck am I gonna fix this? I mean startin to have white stuff hangin in the corner. Owner came home, I was all primed w/how I could fix it, He would'nt have it, said the nitre growing in one upper corner made it more like a cave, and his friends loved it. Maybe a controlled leak? I can see a 1/4 inch plastic pipe behind the brick to keep them moist and a small fan to keep the air stirred. Good luck, Jim
Checker board or honeycomb, if you water from the surface, do not roof the sand filled cells.
I really like the honey comb, it will give a maze effect that is reminiscent of the Old World, which should appeal to wine snobs. The outer storage cells can be doored and rented complete to a major client.
Roof support columns can be incorporated into the corners and porous 'crete used for the walls. Storage cells can be themed seperately.
I see a knockout poured into one wall of each filled cell, maybe with a concrete paver incorporated on the fill side, to hold electronic water valves and moisture sensors. I'ld get a Linux guru to make a controling computor, figuring about $10,000, hardware and software, plus sensors and valves. After roofing, before filling the cells, run a pex to the top, backfill with sand, and connect the PEX to a drip line on top of the sand.
At 59* target temp, you could use chilled water Radiant Cooling in the roof, with each storage cell being a zone, valve in the knockout, controlled by the same computor.
With an open Radiant system, insulating the exterior of the entire structure, and using chilled water to moisten the sand fill so it doesn't raise its' temp, you will have tons and tons of thermal mass.
Let's say the filled cells are 6' across inside, 10' tall, that the concrete has the same density as wet sand and is 8" thick. A cylinder 9'D x 10H is 23.5 cuyd or 38 tons. That puts you in the ballpark of 172Kcals/filled cell specific heat/degree C. Hmmm? You might want to bury the cooling coils in the sand fill so you can quickly get the core temp down. Or plan on back filling them in the winter.
SamT
Nick, the 59º is simple. You have a climate of 1810 heating degree days, base 60º http://www.wrcc.dri.edu/cgi-bin/cliMAIN.pl?nm4799 . Take a look at the distribution. Then it's a simple matter of having sufficient mass to maintain that 59º through the period April-October when you need "cooling".
Passive Annual Heat Storage (PAHS) is usually thought to heat homes. Here in Va (cooling climate similar to yours), it's also our alternative to ac. Keeps us cool this time of year, though our design temp is higher than what you want. The mass doesn't care whether it's heating or cooling. Ours does both. Insulating the mass from air temps with an umbrella is the key. A book excerpt: http://www.axwoodfarm.com/PAHS/UmbrellaHouse.html
Assuming you're planning very few air changes, maintaining that humidity won't be difficult. The temp swings take 2-3 yrs to stabilize, so your client needs to be patient. After that, he does nothing but monitor and be prepared to tweak the system if necessary (more cooling or heating of the mass).
PAHS Designer/Builder- Bury it!