T&T: Fw: $150 Reverse Osmosis System

[Larry N. Brown]

> My wife and I went to the local Home Show in Tucson and ran across an
> interesting water generation system.
>
> This system generates the water from the humidity in the air. While their
> web site shows a freestanding home unit which generates 5 gal/24hrs, they
> also have a military unit which is being used in vehicles in Iraq. They 
> also
> have units aboard several shrinp boats in the Gulf.
>
> They say that a unit installed in a boat would generate about 10 gal/24hr
> because of the high humidity. Instead of the spigot from the free standing
> unit the unit would put the water into your onboard water tank.
>
> The unit uses 110V at 5 amps when running. It will also run from an
> inverter.
>
> The price is about $1,400-$1,800 plus install. the unit must have a lot of
> air flow and probably could not be installed in engine room unless it had
> ducted air from the outside.
>
> On our DeFever we have a 700 gal fresh water tank which lasts us over a
> week, sometimes two weeks, with showers, washer, heads,ice, etc. I am
> guessing we could generate enough water while underway, on shore power, or
> under generator power to keep the tank full most of the time.
>
> I tasted the water and it was much like bottled water, much better than 
> most
> marinas.


As I understand it, this unit draws 5 amp per hour to produce 10 gallons of 
water in 24 hours. That's 120 AH from somewhere to get that 10 gallons per 
DAY. My RO system draws around 10 amps to produce 40 gallons of RO water in 
1 HOUR. Initial cost is comparable to this unit.

I converted two water tanks to fuel tanks to increase my range so I could 
only wedge in 2 x 60 gallon tanks under the aft stateroom bed. Had to have a 
water maker. Looked at several and wound up with RO. On the Navy ships, they 
use evaporators to produce fresh water. There's an outfit up in Shreveport 
that has some models small enough to use on a pleasure craft but not small 
enough for me to put it anywhere on Cigano.

It's a great idea and it's energy efficient if you can afford the space. Run 
waste hot water from a main or genset through a water jacket containing a 
coil and then overboard in the conventional manner. Use a small pump to 
circulate sea water through the coil. This heated sea water then passes 
through a chamber which is evacuated by a small suction pump. This drops the 
evaporation temperature to the point that the water "boils" at the engine 
exhaust water temperature. It's then condensed out as fresh water. Really 
neat. Few moving parts. Most of the energy cost to operate it comes from 
energy that is going to waste anyway- kinda like a super charger. And you 
could use it to fill your lead acid batteries.

Just another piece of the puzzle.

Regards,

Larry and Teri
M/V Cigano, 47' Prairie Sundeck Cruiser
Lying: Covington, LA
N 30 26.7
W 90 07.1