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Creating Water from air? Answered

Hey Guys

Does anyone know a way to convert moisture in air to water? Without using electricity.

Eg using desiccants(slica gel) and solar heat.

The objective would be to get at least 50 ml of water that can be set up in the garden to water the plants.

Preferably using household items.

1 Replies

Jack A Lopez (author)2018-05-17

The usual trick for removing water from ambient, ordinary humidity air, for removing water as water, is simply to provide a cold surface for the water to condense on.

Said another way, the dew point,


for ambient air, is usually a temperature well below room temperature. Thus the usual trick for a magic, water-from-air machine, sometimes called a, "de-humidifier", the usual trick for this requires refrigeration; i.e. a machine that can make things cold.

It turns out it is also possible for water to condense at temperatures, at, or above, room temperature. However for that to happen, you need a source of air that is super-humid. Said in other words, it is possible for air to be so humid, its dew point is above ambient temperature.

As proof of my claim, that water can condense at ambient temperature, or above, all you have to do is examine a solar still.


I don't know if you've ever seen a solar still, in real life (IRL), but if you get the chance to examine one, you can touch the back side of the surface where water is condensing, and you can feel that it is warm. The reason this magic works is because the air inside the still, is very, very humid, hence the possibility of condensing water at warm, above ambient, temperatures.

By the way, with a solar still, the place where the humid air comes from is typically a source of unclean water. You have to feed it dirty water, but usually dirty water is pretty cheap.

Which reminds me: you said this was for watering plants?

By the way, I do not quite see how a desiccant figures into your plans... unless you are asking us how to make cold from heat, using desiccant, essentially a desiccant refrigerator.

Perhaps you are asking us how a desiccant refrigerator works?


Or maybe you wanted to use a desiccant to pull water out of the air, at ambient temp and humidity, then use solar heat to regenerate the desiccant, and collect the water that boils off?

I dunno. I think just the usual recipe for a solar still, fed with dirty or salty water, would be easier.

If there are not instructables here explaining how to build a solar still,


I am sure there are YouTube videos on how to do this. Like this one:

I think this one gives a good overview of how a solar still works (so does the Wikipedia article for "Solar still", linked previously, but the video involves less reading), although the author, Chris Hackett, seems to have kind of a quirky sense of humor.

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