Days of no or short showers could be coming to an end

[Strikhedonia]

Pretty cool idea that possibly could be implemented on a sailboat allowing for nearly unlimited shower time! 5 litres of water for a 10 minute shower plus a low amount of energy to heat the water.

Futuristic water-recycling shower cuts bills by over $1000 - CNN.com

Technology | Orbital Systems

[Lake-Effect]

... that's a brilliant idea.

On land, this is a no-brainer. We waste so much water in single-use washing.

On a boat, I guess it would be feasible if the pump required to recycle and filter the water didn't take much more energy than that required to simply supply/pump pressurized water.

[DeepFrz]

Wow, that is cool. No brainer on larger boats. Smaller boats you have energy to reheat and pump the water and that may make it difficult. Team that up with solar and LiFePo4 and it may work even on smaller boats.

[thinwater]

After watching the video, I was struck by the simplicity. The filter modules (2?) appeared to be simple particle and carbon filters, probably with a sterilizing step (I thought I saw a UV light). This is something that would not be complicated to engineer into many boat systems with a minimum of fuss... for the engineer. If I was cruising full time, this is just obvious.

A few thoughts:

• The recycle is not total. Even a 20% reject and towel off loss insures that salts and soap will not build up. It would be wise to limit the use of soap and conditioners to the bare minimum and to select those that worked best with the system.
• So long as the system is used regularly and flushed with clean water or drained when OOS, biological growth should be acceptable. A tiny amount of bleach at shut down would also do.
• Heating might be a simple matter of running the recycle to the cold tap and leave the hot tap virgin. A clean holding tank would simply over flow over board from the addition of 20% hot make-up.
• I would have a back-flow preventer between this and the other systems.
• A valve and a switch would return you to a once-though system.

Many little problems, all very solvable. I actually think this makes sense of medium size boats that cannot carry huge amounts of water or run a large RO.

[SunDevil]

I saw this article as well. It is pretty interesting technology and the type of efficiency that we should be engineering towards.

Add in some solar thermal water heating, and figure that the hot water going down the drain doesn't need to be heated up as much, and it could solve a lot of problems.

Just have a way to automatically clean the filters and membranes.

[sailorchic34]

From an engineering perspective, I would be concerned that the filters would tend to get clogged with hair and soap. They are not going to get drinking quality water from a few filters and UV though it would be useable gray water.

The company cost savings does not include filter changes, recirc pump maintenance, or general maintenance requirements. Its actually very hard to verify exactly what energy costs they are including in their system. Yes water use is reduced and heating hot water is reduced. But only about 60-65 percent of shower water is hot water anyway. So a 10 minute shower would use maybe 20 gallons of hot and 10 gallons of cold, plus or minus a bit. Plus they have a pump and maybe a UV lamp. Plus a instant water heater to warm the reuse water up 5-15 degrees.

Nor do I see an estimated cost of the installed equipment including GFI protected pumps, heater and lamp.

Sure I could design one for you too. Its not that hard to save the cost of water, but the installed cost and maintenance costs of such a system would not be zero at all. Plus bacterial growth in the water collection pan would be lots higher.

Think about the maintenance the typical shower sump on a boat needs and how often you have to remove the soapy hair from the strainer. Or the smell of the shower water sitting in the bilge for those with on board showers.

I need a bit more information then the company web site provides to even see if its viable. They are providing only part of the total overall operational costs to that system. Lots O marketing, not a lot of substance.

[letsgetsailing3]

It's a fine idea, but the idea of sending the filter back to the company for "recycling" would be a pain for cruisers. You know, single point of failure and all.

[SunDevil]

A simpler way might be to 'pre-heat' the cold water by running a copper tube through the heated water in the drain line. Just the way a heat exchanger works.

It won't help reuse the limited fresh water, but it might be an easy thing to install when building the boat.

[barnakiel]

So ... where do I get one?

b.

[barnakiel]

I love it.

b.

[Khagan1227]

Looks good.

Wonder how long the filters will last in "real life". Carrying a bunch onboard would be a deal killer.

I'd think there would be a cleanable pre-filter before the others to get rid of hair and other "biologicals".

[thinwater]

Someone on some thread pointed out that a bath tub isn't drinking water either. It also makes a difference that the facility is not public.

I would design the system such that:
* The first flush is wasted. Navy shower first.
* The unit drains completely when finished, minimizing growth issues. The last person could add a squirt of bleach one the last recirc, if needed, or one of several other possibilities. Easy, since you want to reset it to once-through for the next user.
* Hot water is once-through. Or just live with warm, which should be tolerable by that point in the shower.
* I would avoid complex filters. I think something functional could be built with course/fine strainers.
* Automated or manual.

I'm not claiming 85% savings in a public shower. I'm suggesting a simpler system that allows a nice rinse after a salt water swim with very little water and a longer rinse period for the long hair set. Every shower would take ~ 1-2 gallons, but few showers would take more than 3-4. If a long coolish rinse on a hot day is what you want, the shower can be long indeed. Fuel savings is of secondary importance to me.

Was the web site a lot of puffing and light on substance? Obviously.

[SunDevil]

Just don't pee in the shower.

[zeehag]

a lot of effort to do what we do anyway...we recycle our used water into clothes washing and other washing ..... dont have to put up with skeeters living in caught water nor about bacteria growing in it either. and i only use a liter of water after a sea water shower even with long hair. cant get better than that.,

[senormechanico]

It seems like a nice idea, but think I'll just stick with my Spectra and solar panels.
I have two pleated 5 micron polyester filters, and when one gets fouled, I swap it for a clean one.
Then I give the fouled one a slosh from the salt water anchor washdown, followed by a bit of fresh water.
After letting it dry in the sun for a few days, it's ready for storage.
Nothing to have to buy to replace.

We've never needed to think about charging batteries due to lifepo4/solar/mppt as described on other threads.