Storing food for the long run can be a challenge and having a spot that is dark, cool and convenient is essential for best results. We designed a spot like this into our home and it has been performing well this summer. Let’s first talk about what you might want in such a room and why.

Photo by Mike Forbes

There are two basic types of cold storage rooms: moist and dry. The traditional root cellar built into the ground serves as an excellent storage space for crops that want to stay moist and not dry out. Root crops like potatoes and carrots can last for months stored in such a spot. We have a spot like this in our water storage building for crops, but we wanted a spot that wasn’t moist, more convenient, and an ideal environment to store our canned food and juice, bulk grains, garlic, and beer.

During the design process, we incorporated a portion of our basement area into a cold room. The room is 8 feet by 10 feet and located entirely below the ground for optimal cooling. Two of the walls are the basement foundation wall (rastra block—a concrete and foam block) and the other two are well insulated conventional walls. I insulated the walls and ceiling with 6 inches of Ultra-Touch cotton insulation (r-19) and 1-inch of Thermax rigid foam with radiant barrier (r-7). All the seams were taped with aluminum tape to keep moisture and air transmission low and then the walls were covered with wood sheeting. The insulation in these walls is to keep the cold air in the room and the warmer air in the house and have as little transfer between the two areas.

It is ideal to have the walls and floor be against the naturally cool earth to keep your room cool. Concrete is an excellent wall and floor material to use for these walls because it has a high thermal mass and changes temperature slowly avoiding large swings in temperature.

I designed a provision into the room to provide a exterior fan on a thermostat to draw cold air in from outside when the temps are low enough. I haven’t installed this yet because I want to see how it performs over the course of a year before doing work that might be unnecessary.

For the door I took an old wood panel door and added 3 inches of foam board to the back and covered it in wood. The door looks old and thin but is actually a highly insulated walk-in cooler type door now.

I built shelving in the room out of left over battens from our house siding and wood sheeting. Building the shelves versus buying shelves gives you the flexibility to design the spacing to your needs. The top shelves hold pints/quart jars and as you go down the shelves will hold up to a 5-gallon bucket.

I finished the room this spring so I haven’t been able to keep the room as cool as I’d like this summer. However, the room is dramatically cooler (10-15 degrees) than any other portion of the basement. The temperatures this summer have been between 55 and 65 degrees consistently with little fluctuation (refrigerators are typically 40 degrees). Moisture levels fluctuate between 40 - 60 percent in the room, similar to those in our home (<30% is very dry and can lead to health issues). Our water room (root cellar) has 70-90 percent moisture.

If you are one who cans food, buys in bulk, or needs to store anything cool and consistent then a cold room might be for you. Many homes have basements or below-grade areas that can be converted to this, or maybe you are lucky enough to have an older home that has a small room in the basement you can insulate. Either way a cold room is an ideal place to store goods for the long term utilizing the earth’s natural cooling abilities.