[miaskows]

Theoreticaly there would not be minerals in all kinds of water made up by condensation of vapour.
By the way if somebody does want his drinking water to be mineralized , it should be easy to meet his demands by simple addition of previously prepared mix of unhydrous salts or their concentrated solution.
Such operation should not be expensive.

[xiankai]

It is my impression that there are systems that distills and filters pure water out of exhaust gasses of engines. I can not think of a way that there would be minerals in that water either, but they drink it. Someone correct me if I am wrong.

if u mean catalytic converters in cars, then i think the water produced are more used as an engine coolant or just evaporated by the hot gases.

[miaskows]

I think Mr. billnotgatez meant the water that formed by burning of the fuel, for example:
C7H16 + 11O2 =7CO2 + 8H2O
consequently burning of  100 gr of heptane produce 144 gr of water vapour diluted with N2.

[Corvettaholic]

I'm trying to follow how to go about building one of these, and its pretty much using a normal air conditioner and scooping the water out of it instead of letting it drain out? Now how would I need to reroute the plumbing so I get more water and less cooling? Just so happens I'm getting 3 window-mount A/C units for free this week! Some nice chap has graciously decided to donate them to science, my science. Now I just need to convince a company to donate some solar panels and deep cycle batteries...

[movies]

My guess is that they have a highly insulated coolant box in the base and then tubes run up from that box into the area behind the grating.  There, the moisture in the air is condensed and collected below.  There must be some sort of pump mechanism to bring the water to the top of the unit for dispensing.  The key would be to use a metal that won't corrode or leech into the water during use.  You'd also need a filter to avoid sucking in a bunch of dust.  That filter would probably need to be changed pretty often.

To add to the discussion about drinking distilled water, I have heard of studies where they compared many different waters from many different sources with a large sample size and it was found that the "best tasting" waters were those that had relatively high concentrations of magnesium and sulfates.  Evian spring water, for example, has high concentrations of these ions.

Also, there is no doubt that drinking large quantities of distilled water will cause leeching of electrolytes from the body.  It's a simple equilibrium problem; our bodies operate in a medium with high concentrations of ions (sodium, potassium, etc.) which are essential for life.  If you add a bunch of pure water, the equilibrium requires that these ions be diluted to a greater extent than if the water you drink already has some concentration of ions in solution.  You're not going to leech out the heavier metals (iron, molybdenum, etc.) because the important ones are concentrated in proteins, but the free ions like sodium and potassium (which are responsible for a host of cellular processes) are not tied up in proteins.

[miaskows]

There are number of  possible technical solutions:
1) and simplest one, let us to call it "Cold air Mode":
Q- flow rate of inlet air (with temp t1)
W- electrical energy we need to cool Q up to t2
 If you operate your A/C in the winter time you need less energy to condense water from air, because inlet temp. of air almost equal to dew point.

Let for Q=const; t2=const (built up parameters of regulators of A/C)
The only parameter we are going to change is t1:
What would happen in this case?
Your A/C has regulator that just stops it's compressors when temp.drops up to t2. If t1=t2 the A/C is in
standbay. During that time it doesn't spend energy for compressing of freon.
If you direct your outlet flow of cooled air to heat transfer device in such way that inlet flow would enter it in counter -current direction , your A/C would get the same air flow (Q) with lower then environmental temp.
Consequently it would work lesser time than usual and would spend less energy.
But , and it is very important, you are going to collect the SAME AMOUNTof water condensate that you would have been collected during usual operating of the A/C.
Conclusion:
Solution No 1 makes it possible to collect usual  (relatively low) quantity of water condensate by spending lesser electricity.
The problem is-heat transfer device. It must be of air/air kind.
(We have not such one in our air conditioners- heat transfer radiators there are of freon vapour/air and liquid freon/air kinds.)
Both freon vapour and liquid freon are much more dense flows that air itself and besides have highter difference in temperature than air/air system, and consequently need pipes of  smaller diameters than air.
Simplest air/air heat transfer could be built from long box , inside of it a lot of iron plates making tens of sections. It must be constructed in such way that  
first section carried outlet flow of cooled air, second inlet flow of room temp. air, third outlet flow and so on.
The flows don't mixed one with another but only transfer their heat.
Other solution is a box that contain a lot of pipes. Pipes for ,say, inlet flow of air, the remaining space of box between pipes for outlet flow of air.
You probably may  find different construction of such devices in net. The trick is to get one that would make the job under flow rate conditions of common A/C but would not be too big or expensive. Without calculation it would be done by simple stage by stage raising of number of sections and searching the result of it. Or you can write down flow rates and temp. of both flows and search for a device that meets the demands.

[Corvettaholic]

Well the way I build things is Thomas Edison style, I just go for it and see if it works, then improve from there. So I think I'll tear apart one of the free A/C units and try to rig up a water collector. Once I get it working as well as I can, then I'll resort to calculations to find the optimal way of putting it together. Until that point, I use free/cheap stuff to keep costs way down. There's a lot of useful stuff sitting around in landfills, you'd be surprised!

As far as filtration, what about using high voltage? Have the water outlet run through a strong EM field and 'grab' metal that way? Then blast the snot out of it with UV-A light to kill the critters in there. UV LED's can be had for a reasonable price, even ones up to 20watts! Then again, blowing 20 watts on a light source IS a big expenditure of precious power...

[movies]

Not all metals are magnetic though.

[Corvettaholic]

Hmmm... good point. Any recommendations for a filter system then? Suppose in a pinch I could just a coffee filter. Or use solar heat to boil off water from the collection bin, and re-condense somewhere else without all the floaties following it?

[miaskows]

You can use solar heater for preheating water up to ,say,60 oC and continue heating and boiling by common electrical heater. It is simplest solution (widely used in the world). In the other hand i saw article concerns investigation in that field. They claimed that by exposing to a summer sun of properly isolated box covered with 5-7  sheets of a clean glass (the sheets of the glass were adjusted to the box in such way that there was 5-10 millimeters of air between them) and black bottom, they detected inside temp. of 120-140 oC (!). But it is sort of record.

You migh condense boiling water by using of air cooler.
Even in hot summer day temp. of air raised as high as 45 oC only . It is still pretty good for condensation of boiling water.

Another way -using your cold tap water as cooling medium. Then you have to get big water tank for collecting of outlet water flow.

[miaskows]

Ecpecially elegant solution of recupearation of bin water by using of solar energy could be described as follows:
Distillated salts free water circulated in your closed solar heater (it is important to use such medium and not bin water itself  for evoiding deposition of oily organics ,CaCO3 and other contaminants  on elements of the construction). That flow  heats  bin water in counter curient heater up to ,say, 60oC.
The preheated bin water distillated by using of vacuum pump and cooled by air cooler or (better) by cold tap water flow.
You can use very low vacum to get water boiling at 50-60oC.
There are a lot  of cheap or even  free ,used  small vacuum pumps everywhere (chemical plants and other outfits only happy to get rid of them)
Some of them should need some repairment.
Such pump (from my own experience) can work nonstop a lot of time, ecpecially if the vapour is not corrosive (as it is in our case with water vapour).
Small common used vacuum pumps powered by somthing like 300-500 watt and could evaporate a lot of hot water.

[miaskows]

Say, you suceeded by covering all of your roof with solar heaters (of common used design -no exotic parabolic reflectors or sort of it, just glass covered square boxes  with pipes inside, the like one can see on every house in the warm countries). Then you would heat  up a lot more water than you need for your bath.
Say, as well, that you have got for yourself  a small vacuum pump. You can regulate the pump in such way that it would get constant vacum, say, 0.3 Atm. As you know  every boiling point value is corresponds to some exact pressure value. Consequently, if you regulate your pump to build up vacuum of 0.3Atm, your preheated waste (bin) water would boil at 60 oC exactly. Water with lower temperature  (say,45 oC) would circulate via your distillator and get out without boiling.
The whole system would regulate itself!! There is sun outside there-you collect distillate, cloudy wether- no distillation would proceeds.Properly adjusted and maintained vacuum pump almost would not  spend an energy. Distillation of the water even such low temperatures and vacuum would be completely covered by solar energy.

[constant thinker]

Water condensor to me makes me think of an A/C as was said already. Why not just make an A/C on steriods. Get some copper tubing and a compressor. I'm sure your smart. I live in NH and it gets humid. Humidity is the killer. It makes things feel so hot. In the winter it gets cold though.

[Corvettaholic]

See, there is NO humidity in arizona. I was using a swamp cooler last week until I got my AC fixed, and that made the house real humid. What about dehumidifiers? Those don't have a compressor, do they? If I can avoid a compressor to condense water, that would be great because compressors eat so much power. I like miaskows idea using a vacuum pump, but I want to go more low-tech than that. The less parts involved the better. Why? Because I have to build it.

[constant thinker]

O. I don't know how dry it can get in Arizona. I've never been out there. It can get really humid here in New Hampshire. My toilets are great water condensers. Lots of water drips of the bowl and holding tank. I have to put a towel under it to prevent water damage.