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Evaporation-based Water Purifier Cone

Water Cone Evaporation

When you evaporate and condense water, the condensed water is 100% pure water. This means the purified water is completely safe to drink, as nasty chemicals and bugs do not evaporate with the water. The WaterCone is a very simple gadget that purifies water by the process of evaporation.

Water Cone Diagram

Water is poured on to the black tray. As water evaporates, it condenses on the inside of the clear plastic cone. The condensed water then runs down the sides of the cone into the outer tray. When the outer tray is full, you then drain it into your water vessel of choice.

Water Cone being drained

The Water Cone can hold up to 1.7 litres of dirty water at a time, and it only takes a few hours for the water to be condensed. It costs around $30 (even less with mass production I’d imagine), so is easily cheap enough for mass distribution. The cone is designed to last about 5 years, so that’s a great level of usage for a very low-tech water purification eco gadget!

Source: EcoFriend

Comments on this entry are closed.

  • paul henson June 2, 2009, 10:16 pm

    where can I get a few of these water cones?

  • Dan (EnviroGadget Writer) June 3, 2009, 9:00 am

    I suggest you go to the designer’s web page:

  • hubert June 8, 2009, 10:32 pm

    Does it take salt off from ocean water ?

  • Dan (EnviroGadget Writer) June 9, 2009, 9:47 am

    No, it takes clean water from contaminated water (or sea water) using evaporation and condensation.

  • Eric Wade December 5, 2009, 11:50 am

    Why can it only be used for 5 years? Does the plastic degrade? What about making it from glass? 5 years is not long in my opinion, or at least long enough.

  • Dan (EnviroGadget Writer) December 7, 2009, 11:42 am

    Hi Eric

    I get the impression that the plastic degrades due to UV exposure. I agree that 5 years is not long enough though. Glass would be more expensive, and much more fragile, defeating the point of these particular filters.


  • Eric Wade December 11, 2009, 9:41 am

    I think glass is the way to go. I think people would be careful handling them if their supply of drinking water relied on them. And glass handles could be put on them, maybe a rubber base coating so they dont shatter. What about having the pan more elevated in the bottom with a boyant substance underneath. The glass part that receives condensation would dip below the pan. The Watercone could be floated in the sea or a lake and the contact of the glass with the cooler outer water could cool the glass and speed up or enhance condensation.
    I am thinking of asking a glass blower to make one for me.

  • Dan (EnviroGadget Writer) December 11, 2009, 10:26 am

    Hi Eric

    Don’t forget that the glass will need to be pretty thick to be robust, plus a large surface area to be effective. I would expect the glass to be very heavy, around 5 to 10kg!


  • Eric Wade December 14, 2009, 7:22 am

    Hi Dan.

    I am going to Bali, Indonesia in a week and trying to get a glass blower to make a ‘watercone’. I am not a scientist but I am wondering:

    1. What is the optimal angle for the ceiling of the ‘watercone’ to promote condensation?

    2. How does the volume inside the ‘watercone’ compared to both the surface area of the ceiling and surface area of the pan holding the water change the effectiveness of the ‘watercone’?

    3. What kinds of glass are better able to conduct heat? The inside of the ‘watercone’ would need to be as hot as possible to evaporate the water but the glass needs to be cool to promote condensation.


  • Dan (EnviroGadget Writer) December 14, 2009, 9:45 am

    Eric, you’ll need to experiment on each of those parameters.

    1. No idea, but I imagine that surface area plays a part. I think 45 to 60 degrees might be worth trying.

    2. You need a large water collection chamber, and large surface area helps with more space for condensation. That’s about it I guess.

    3. Condensation occurs when one side is cooler than the other. The inside will be warmer due to the greenhouse effect.

    Might I suggest you contact the original designer though? I’m only guessing with these answers.


  • Eric Wade December 14, 2009, 12:12 pm

    Dan, I’m not sure the original designer would be happy that I am basically trying to make a ‘knock-off’ of his design.
    But thinking of the volume of the ‘watercone’ I think the larger the surface area of the pan and roof but smaller volume inside would accelerate condensation. If the volume is smaller then the air would become super-saturated with water vapour faster and more likely to condensate. I think. 🙂

  • Hristo December 28, 2009, 5:22 am

    Just want to add/correct that it actually makes sea water drinkable. Salt does not evaporate with water. I am pretty sure I also saw it in one of the videos of that product.

  • Em April 23, 2010, 3:13 pm

    Hi there, just wanted to comment on fluoridated drinking water. It is my understanding that this device would be affective for defluoridating drinking water, that the fluoride ions would be left in the waste water. Please correct me if this is not an accurate assumption.
    Thanks, Em

  • Dan (EnviroGadget Writer) April 26, 2010, 1:40 pm

    That’s a correct assumption. Evaporated (and condensed) water, to all intents and purposes, is pure.


  • Adam July 23, 2010, 8:48 pm

    It would not be healthy to rely on purified water as a source of drinking water. Your body needs the minerals that occur naturally in surface and groundwater and the minerals give the water taste. Drinking too much purified water can be harmful to your health.

  • Eric Wade July 26, 2010, 11:18 am

    I have researched this a little. From what I have read, drinking distilled water may help in cleansing your insides. I do know you need the minerals from regular drinking water but you can also get this from eating fruit, vegetables and other drinks not made with distilled water. There must be some groups of people who in the past or even now drink rain water which is also distilled and they survive. I think people can live a healthy life drinking it. At least, I hope so because I am devoting a lot of my time into this gadget and want people to benefit. But if I am proven wrong then I will scrap the thing.