basement root cellar insulation question

Hello friends,
We are building a new home and putting a cold room in the basement to function as a root cellar.  The rest of the basement will not be finished or heated/cooled.  The cold room is in the southeast corner of the basement area.  The basement is only under the center part of the house.  So there is crawl space on the south and east sides of the cold room, and basement to the north and west sides. (plans attached)
I live in the mountains of Idaho.  Falls can be pretty warm and word in the area is that it's hard to get it to cool down in the fall, but then it's good for the winter and spring.  Sounds like venting to the outdoors is key to get in cool air whenever there is a cold spell in the fall.  Any advice on the venting?  Any advice on insulation?  Should we bother with insulation around the cold room?  Walls or ceiling?  

I can't answer your question though I found some threads that you or others might find helpful:

https://permies.com/t/223803/Building-basement-cold-room

https://permies.com/t/37748/Building-cold-room-garage-fix

https://permies.com/t/27681/Fridge-cold-room-pantry-ice

If there will be heat generated in the mechanical room, I advise insulating the wall between that and your root cellar.

I am not sure what to say on the other walls. I am an architect in the hot, mostly-basementless south. Down here I would probably opt for placing the root cellar in a corner, against two adjacent perimeter walls in order to maximize earth contact. I don't know what the temperature range your cold-climate unconditioned basement might experience, but I suspect it must stay cool all year since you located the root cellar away from perimeter walls.

Since the floor of your basement is below your frost line, and your root cellar is located away from the perimeter, I see no reason for floor insulation. In fact, it would seem that an uninsulated floor would provide your only connection to the wonderful cool thermal mass of the earth. Definitely insulate between the ceiling of your root cellar and the living space above.

I have limited experience with basement root cellars, so maybe someone with more direct experience will chime in. (I'm jealous of your root cellar. Maybe someday I will have one.) Good luck and enjoy!

Alison, this radon venting that you are planning, is it because of known danger in the area, or just to make sure that *if*  there is radon, it can be vented out?
It is a good precaution to vent your basement/ root cellar either way: Anything that gives you better control of the environment in the cellar is a good idea. Nice professional looking plans, BTW.
If money is no object, insulation would be the preferred path.. Insulation may be a bit pricey up front, but it pays dividends forever, not to mention that if insulated, it can be more "finished".
I see that you also have a relatively large crawlspace. That might help you separate things that must be separated, like apples from potatoes, for example, so you could create a pretty nice setup for yourself.
Personally, a crawl space needs to be deepened to be useable, and have 2 entrances [1 from inside and 1 from outside of the home]. That would be perfect. Otherwise, crawlspaces tend to be areas that are hard to visit, so we tend to put a lot of junk we don't use, and it invites varmints: spiders, mice, snakes, the occasional racoon...]
As you can guess, I have a thing against crawl spaces, but that's me [at 75, I don't see myself crawling under my house to retrieve something. I would always argue to make it more livable].
If you grow sweet potatoes, you would also need an area for that. [room temperature  and fairly dry after a curing period with high temperature and humid condition.]
I have found the recommendations from Johnny's seeds to be really helpful: I hope you will too.
https://www.johnnyseeds.com/growers-library/methods-tools-supplies/harvesting-handling-storage/storage-crops.html
Essentially, you have several combinations around temperature and humidity. Cold and dry, cold and moist, warm and dry, warm and humid Some crops like it warm and dry [onions] whereas potatoes like it cold and humid.
In other words, start from the crop's needs and work backwards to provide the best storage environment you can afford.

here is the Elliot Coleman design https://www.motherearthnews.com/diy/build-a-basement-root-cellar-zmaz04djzsel/?SlideShow=1

I agree with the above person. I would insulate and waterproof the basement. Although if your climate is dry, soil is sandy, and it will only be a root cellar forever than you might be fine. Although the concrete will last longer is waterproofed.

Hello,
On another thread, there were photographs of a Finnish woman’s harvest. It was rich, glorious,  colourful bedlam. There was a question about storage, where can you sit as most surfaces of any description are spoken for.
A bit like here really though harvest this year has been very modest.

Anyway, why do I mention this?
Because I have an insane desire to do evrything at the same time.
I want a root cellar, yesterday.
Well, my drinking water supply has changed its arrival spot so now there is a deepish area, lined with, is it paving stones and 2 more slabs for cover.
It’s about 80 x 100 x 90 cms. 80 is the depth. Haven’t actually measured anything but isn’t that just dandy. Somewhere to store something, cool/cold, humid, accessible to our furry friends, I suspect, But a God send nevertheless.
In fact, there are two of these underground water meter pits.
Hooray!
Wishing us all a splendid weekend.
I won’t talk ‘holiday’; it wasn’t a joy for everyone.
Anyway blessings to all everywhere, even to rodents, as long as they stay outside.
Marie-Helene