Solar still
From Trail-Finder -- Dedicated to getting you outside
Contents |
Overview
A solar still is an easy to build, easy to use device which allows you to turn almost any liquid into drinkable water. Although not portable, and is impractical for normal use, when used in an emergency, it can produce enough water to live.
Materials
- Waterproof sheet: This can be a raincoat, tent rainfly, or anything else waterproof.
- Collection cup: A cup, bowl, or anything else that collects water.
- Hole: Normally dug into the ground, but any hole in anything where the inside gets cool will work.
- Small weight: A tiny rock, to force the bottom down
Construction
- Dig or find a small hole, or use an existing one.
- Place a collection cup in the middle of the hole.
- If available, pour liquid into the hole. Salt water can be used, as a solar still will desalinate the water. In an emergency, urine can be used.
- Place a waterproof sheet over the top of the hole, completely covering it.
- Cover the edges of the sheet with dirt, small rocks, etc. This will hold it in place and prevent most air from getting out.
- Place a small rock on top of the sheet, set so it rests directly over the top of the collection cup.
Operation
As the day warms, it will evaporate the water in the hole. Impurities, including salt, will not evaporate. The warm, humid air in the hole will condense on the plastic sheet, and run down to the weight, dripping into the collection cup. The more sun you have, and the more water in the hole, the more drinking water you will get.
As needed, add liquid to the bottom of the hole and remove the clean drinking water.
