Water from dew!

[scotjute]

Years ago someone told me that if
you dig a funnel shaped hole about
30-36" wide and 30-36" deep and
lined it with plastic, in the morning
you would have about a cup of water
in the bottom. The theory was that
no matter where you were, the earth
temperature at that depth would be
sufficiently cool enough early in
the morning to start condensing
water out of the atmosphere.

Tried it once in north Louisiana
in the middle of summer and did get
about a cup of water the next morning.

Has anyone else ever heard of this,
or tried this or any other plan for
collecting water?

 

[DancesWithKnives]

About six months ago I (and some other folks) started a couple threads on water condensers. There is a lot of interesting information in the archives. Some people refer to them as stills or desert water condensers so you might have to try several different search words.

I've used plastic sheets to collect dew at both surface level and in holes such as you describe. Because conditions often vary from night-to-night, it is hard for me to say whether the hole helped a lot. However, if you dig the hole during a warm day, you will probably sweat off almost as much moisture as you collect the first night. You'd obviously get ahead on successive nights (or if you dug the hole on a cool night).

Sorry I couldn't be more helpful.

 

[Random Mutant]

I believe that Australian Aboriginies would tie sponge-like grass bundles to their ankles and walk through grass wet with dew in the early morning, and squeeze the water out of the bundles. Apparently it is possible to supply a whole day's water (with the proper container) with a small amount of work in the morning. The water should be as clean as the grass it is on, because it condensed out of the atmosphere. The only problem with this method is getting up early enough, you have to get it before the sun rises . Yet one more reason to put a handkerchief in a survival kit- bandanna, sling, prelminary water filter (before boiling) and a sponge for soaking up early morning dew.
Studies have been done on solar stills similar to what you describe, and they have found that they are not really efficient enough to supply a full day's water without multiple stills.

 

[Fallschrimjager]

Was taught same as the Aboriginies at survival school but by using a extra pair of socks over your boots. Walk trough dew covered grass and wringing them out as they become soaked into a container.