Comments on: I need a Name for my Science Fair Project!! My Short Title is " Water Out of Thin Air"? http://www.eblips.net/solar-energy-society/i-need-a-name-for-my-science-fair-project-my-short-title-is-water-out-of-thin-air/ Helping Relieve Poverty Though The Provision of Solar Energy. Join Us! Sun, 13 May 2012 07:51:59 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: gintable http://www.eblips.net/solar-energy-society/i-need-a-name-for-my-science-fair-project-my-short-title-is-water-out-of-thin-air/#comment-2096 gintable Tue, 16 Feb 2010 09:36:59 +0000 http://www.eblips.net/solar-energy-society/i-need-a-name-for-my-science-fair-project-my-short-title-is-water-out-of-thin-air#comment-2096 Well, water can be extracted from air. Your air conditioner is a device which accomplishes this task. If you use your air conditioner in a humid region, you will see a flow of condensate draining from the device. In the case an air conditioner operating in humid regions, you usually discard the condensate. Here you are looking for a system which will save and use the condensate as domestic water. Will it work in a dry region? It will, but it will be much more difficult. And its economics may not be as ideal as you may think. I'll give you some typical data and show you just how expensive the water will be. At your request, I will e-mail you how I did my calculation if you are interested. Condition of naturally existing air in a dry region: Temperature: T1 = 30 C Relative humidity: phi1 = 25% Air pressure: P1 = 100 kPa System of extracting water: You limit the refrigeration device from cooling air below T2=2 C (to prevent formation of ice). COP of ideal vapor-compression refrigeration operating between T1 and T2 with refrigerant R134a: COP = 8.5 Price of electricity: 4 ¢/Megajoule. This is equivalent to about 15 ¢/kw-hr. -------------------- Results of interest (all per kilogram or liter of water desired, unless otherwise stated): Mass of incoming air required: m[1] = 447.5 kg Minimal Refrigeration load: Qnet = 15.13 MegaJoules Electrical energy required: Wreq = 1.781 MegaJoules Price per liter of water: CPL = 7.124¢ Price for about four liters of daily drinking water (likely needed in dry climate): 30¢ Price for about 350 liters, typical daily use for all purposes: $25 Comments: I think $25 every day is a lot of money to pay for my daily water use. Also, we cannot use this air directly in our homes, because it will be too dry to for human comfort once it is warmed. We will need to route it in ducts around our house (to cool our house without accepting the air's mass) and then exhaust it to the background. Another practical consideration is that a lot of non-water build-ups occur on the outside of evaporator coils. We will need a good design of filtration to prevent dirt and mold from become part of our water supply.<br><b>References : </b><br> Well, water can be extracted from air. Your air conditioner is a device which accomplishes this task. If you use your air conditioner in a humid region, you will see a flow of condensate draining from the device. In the case an air conditioner operating in humid regions, you usually discard the condensate. Here you are looking for a system which will save and use the condensate as domestic water.

Will it work in a dry region? It will, but it will be much more difficult. And its economics may not be as ideal as you may think. I’ll give you some typical data and show you just how expensive the water will be. At your request, I will e-mail you how I did my calculation if you are interested.

Condition of naturally existing air in a dry region:
Temperature: T1 = 30 C
Relative humidity: phi1 = 25%
Air pressure: P1 = 100 kPa

System of extracting water:
You limit the refrigeration device from cooling air below T2=2 C (to prevent formation of ice).
COP of ideal vapor-compression refrigeration operating between T1 and T2 with refrigerant R134a: COP = 8.5
Price of electricity: 4 ¢/Megajoule. This is equivalent to about 15 ¢/kw-hr.

——————–

Results of interest (all per kilogram or liter of water desired, unless otherwise stated):
Mass of incoming air required: m[1] = 447.5 kg
Minimal Refrigeration load: Qnet = 15.13 MegaJoules
Electrical energy required: Wreq = 1.781 MegaJoules
Price per liter of water: CPL = 7.124¢
Price for about four liters of daily drinking water (likely needed in dry climate): 30¢
Price for about 350 liters, typical daily use for all purposes: $25

Comments:
I think $25 every day is a lot of money to pay for my daily water use. Also, we cannot use this air directly in our homes, because it will be too dry to for human comfort once it is warmed. We will need to route it in ducts around our house (to cool our house without accepting the air’s mass) and then exhaust it to the background.

Another practical consideration is that a lot of non-water build-ups occur on the outside of evaporator coils. We will need a good design of filtration to prevent dirt and mold from become part of our water supply.
References :

]]> By: Devine Caesar http://www.eblips.net/solar-energy-society/i-need-a-name-for-my-science-fair-project-my-short-title-is-water-out-of-thin-air/#comment-2095 Devine Caesar Tue, 16 Feb 2010 09:25:59 +0000 http://www.eblips.net/solar-energy-society/i-need-a-name-for-my-science-fair-project-my-short-title-is-water-out-of-thin-air#comment-2095 What you say is impossible unless I am missing something and the laws of physics were changed over night. I see no problem with calling it water out of thin air though.<br><b>References : </b><br> What you say is impossible unless I am missing something and the laws of physics were changed over night.

I see no problem with calling it water out of thin air though.
References :

]]>