We had a 2" pipe for ours. Remember to cover the outside opening with mesh, though, because the little meecies will definitely get in otherwise! Ours was on an outside wall on the south side - obviously it didn't work out, and we never did make another one.

I'm not convinced you really need to run a pipe to the outside in our climate. Insulating a room and blocking it completely off from your houses heating system should be good enough, shouldn't it? I would also make sure the door is insulated and you might even want to put a weather strip on the bottom of the door. Even in summer the cold floor of your basement should keep the room cool.

Also replace older light bulbs with compact fluorescent light if you have a light in the room. You might even think of putting in a little motion sensor light switch and setting it to its minium time (3 minutes). That way you can't forget to shut the lights off and they won't generate much heat.

I'm doing this to a room in my basement later this September. So I'm interested in anyone else's comments in this thread.

We finally built a garage after 10 years without one. We attached the garage to the house by way of a triangular room (garage is at a right angle to the house). Under the new room we made a root cellar by busting through the basement wall. It's about 5' feet to the ceiling of the room, with a poured concrete floor. We made a trap door to cover the opening in the basement wall and attached steps to it. Nice and cool in there with no holes to the outside.

Don't really have much experience but remember when I was a kid our house had a cold storage room. It was in the basement northeast corner with the concrete walls un-insulated. The walls separating it from the laundry room were insulated and there was a door that has some insulation on the back of it as well.

I recall it as being fairly cool, but not refrigerator like. Perhaps 8 to 10 C at the coldest time of year but we stored potatoes (bought vegetables) and my Mother had shelves with pickles, etc.

I have debated on trying a Âmini version of this, perhaps in the NE corner of the basement where the concrete floor meets the concrete walls. Maybe build something like a box, with plywood for the "front" sides and a lid, but use the concrete floor as the bottom and concrete walls as the "back" of the box. All I would store there would be plant bulbs, so it need not be super cool, but cooler than the normal 16C the basement is in winter. Has anyone tried such a "mini" version of this? Any problems with mould because there would be no air circulation in that corner?

Interesting topic, especially because we are all thinking fall and storing vegetables, bulbs, etc.

Glen

I have also been interested in this topic for a few years now but haven't built anything yet. I used to work for a vegetable storage engineer and I asked him what would be best for home vegetable storage. It was pretty much what Andrew described, but with a fan. Preferably one on a timer that could cycle on and off.

The engineer's specialization was potato and carrot bunkers that can store root crops for up to 18 months. Apparently the key to potato storage is low temperature (but above freezing of course), high humidity and high air flow. I don't imagine bulb or other vegetable storage would be much different but it might vary somewhat.

My mom used to have an ideal situation when I was a kid, the basement had a crawl space off it, accessed through a regular basement window-sized opening, and it was only 3' high and uninsulated. We could fill it and block off the opening and it stayed very cool but not frozen. Only problem was it was my job to crawl in there and get stuff out. I was terrified of it LOL

Glen, i've thought of the same thing in our porch. Once when i had planted tulips in containers, i put a thermometer on the concrete floor in a corner to check if it was cool enough to keep them there. It stayed at 11°. The box idea might just might work there too.

Our porch extends out from the house and the basement extends under the porch.....making a natural small room. We walled this off. Insulated both the door and wall that interface with the rest of the basement. No heat in the cold room and no pipe to the outside air. It is on the south side of the house. Temps stay close to freezing +35F/+1,+2C) all winter. In fact, during very cold winter weather, we open the door so warm air can come in from the rest of the basement to prevent the potatoes from freezing.

I would suggest, if building a cold room to locate it next to an outside basement wall. Insulated and unheated, such a space should have no problem staying very cold. Remember to insulate the ceiling in the cold room....so heat does not enter via the floor of the heated house.
Jan

We should have extended the basement under our porch. However, we didn't!

I'd like to add, too, that if you plan on building a cold room, the northern corners of the basement would be better, and the northeastern corner would be the best.

I have an old stone barn with a garage under the one side of it. Can I use this for a cold cellar for vegetables?

If it doesn't go below 0 in the winter, it should be okay.