How to Make a Dry Well
How to make a Dry Well or Pit for keeping food cool.
- Problem: Fruit and vegetable storage in hot or cold climates
- Idea: Using the thermal inertia of the ground to store the food at a constant temperature
- Difficulty: Digging the ground, lining of the hole's walls, insulation of the lid, dry ground, rain infiltration.
- Price Range: Less than 10 dollars
- Material Needeed:
- Geographic Area: Everywhere
- Competencies: Little
- How Many people? From one on
- How Long does it take? According the soil quality and used materials, from a few hours to a few days.
The earth is usually cooler than the air, so you can keep food cool in the hot weather (or protect it from freezing in the cold weather) by storing it in a pit.
A dry well is just a pit that keeps the dirt from falling in on your food, with an insulated lid that is easy to open and close.
Dig a hole with a flat bottom at least a few feet or a meter deep in a place where water will not seep into the hole from the soil. Line the walls with rock, clay, or other available material to keep them from falling in. A section of cast cement or other drain pipe can also be used to line the walls, or you can bury an empty barrel with the open end up. Build or leave a rim sticking up above the surface of the soil to keep out rain or loose dirt from falling in. A layer of small rocks on the bottom is a good idea to keep items clean and out of any water that may get in. Make a solid lid to cover the entire top opening -- out of wood, woven brush, metal, or concrete -- add a layer of insulating material (hay, dry leaves, or even soil will do) to the lid or lay it over the lid.
One I've used is a 3 foot section of cast concrete drain pipe, set in a hole a few inches shallower than the pipe (so that the pipe sticks up above surface of the ground to keep rain from running in). The lid is a circle of plywood a few inches larger then the end of the pipe with a circle of 2-inch-thick rigid insulation (such as Styrofoam) cut to fit down inside the pipe glued to the bottom of the plywood lid.