Recycling shower invention

[sasktrini]

http://www.cnn.com/2013/11/11/tech/innovation/futuristic-water-recycling-shower-orbsys/index.html

This is just something that I thought was really neat.  I wonder... separate grey water tank, pump, filter and heater?  I can see humidity being a problem for an RV...

I'd actually like to see a system where grey water from the sinks could be used for toilets.

So if there was one system for bathing and another for fresh -> black water, the critical factor would be really good filtration from the grey water pickups.  I would bet some chlorination for the shower tank may be in order as well.

Anyway, just saw this, and thought there may be some dreamers ambitious enough to make a go at it!

[Lefty]

Not a bad idea... You could theoretically plumb up the toilets water supply line to the grey watertank.. Using its own dedicated 12v shur-flo pump.. as well as a decent water filter to prevent anything that might have been washed down the sink (food debrisfrom dishes or cooking prep...).. It certainly wouldn't hurt the toilet.. and the dish detergent being added a bit at a time might keep the toilet internals a little cleaner too. I wouldn't want to take a shower with grey water though... ewww

[cosmic]

That's a great idea. I think the key is filtration as fast as the water can be pumped. that's the hard part for us simpletons. Hm?

But Heck who cares if its toilet water.

[ClydesdaleKevin]

The problem you would run into with a full grey water filtration system is the size it would have to be to fully filter the grey back into potable water, and then the huge amount of maintenance of such a unit.  Trust me...since we boondock in the desert a lot, we looked into this and did a lot of research.

Since grey water is from the sinks and shower, it is going to contain everything from body hair to food grease, and then all the detergents and shampoos you use. 

A system capable of filtering out the soap and grease is the biggest problem.  There are two methods that would work...distillation, either solar or heat (electrical or propane), and a reverse osmosis system.

The former would have to be pretty big, especially a solar setup, but its the easiest and cheapest to do.  I designed a system myself (although I never built it), where your grey would go into a big round metal tub, like the kind you can buy at Tractor Supply to water livestock.  In the middle of the tub would be a 6" catch pipe facing straight up, at a 90 degree angle to a pipe below it that would exit the side of the tub, sealed around it so grey couldn't leak past it.  Over the whole unit you would drape a clear plastic tarp and secure it around the edges, but not too tight.  In the middle of the tarp, you would put a weight, like a rock, so that the tarp would convex inward.  This would of course have to be put in full strong sunlight.  The sun would evaporate the grey water, which would collect as condensate on the inside of the tarp.  Because of the weight, the condensate would drip to the middle of the tarp, the drip down into the 6" pipe, then down into the lower pipe, where it could be siphoned back into the freshwater tank. 

Big and clunky, but it would work...how fast of course would depend on how much sun you had.  Maintenance would be yucky...mucking out the sludge of soap and grease and whatnot once in a while...but this was the cheapest system I could come up with.

Steam distillation would be a similar process, also resulting in pure water that could be piped back into the freshwater tank...and the heat source could be either propane or electric.  Same idea as the solar setup, but you could make it a lot smaller.  However, a lot of heat, and therefore money, would be required to produce a sufficient amount of water, and then you still have to clean out the nasty sludge once in a while.

Reverse osmosis systems could also do it.  But they are hellaciously expensive, huge for any usable amount of output, and the filter membranes would have to be replaced often because of the soap and grease...and those membranes are crazy expensive!

Just filtering the water for use in the toilet would give you other problems.  You'd have to filter it enough to at least get the grease out of it...which would clog your filter in no time.  Otherwise the greasy water you put back into your toilet is going to leave a nasty greasy ring around your toilet, resulting in the use of even more water to clean it off, and soap or a degreaser of some kind.

Just my thoughts on the subject, which we thought through carefully a while back...lol!

Kev

[sasktrini]

I may not have led where I was thinking… I was thinking the shower would have to be isolated from the sinks… much like the system demonstrated in the video… one grey tank for the shower, one for the sinks.  In the case of the system for the shower, it wouldn't be much different than a system used for a jacuzzi, would it?  If you think of the idea only pertaining to the shower, how do you think that would carry over to the RV world?

[ClydesdaleKevin]

Sounds a lot more doable, since the water at that point would only contain soap, and that certainly wouldn't make a greasy mess in the toilet!  Heck, you could pretty much use it directly right to the flush water without filtering as long as you had a hair trap over the drain.

Kev

[circleD]

What about a system like a house septic tank. Put a new pipe in through the side at the top and have it 90degree down with enough pipe to go about an inch or two from the bottom so it will only suck up from near the bottom and the grease and soap will be floating on top. Yes it all mixes going down the road but you might try little test jars of soaps and grease to see how quick they settle. If you could then make a small strainer just to catch chunks of stuff and when the pump shuts off, the chunks will fall off unclogging itself. With the pipe coming in at the top you can cap it later and not worry about big leaks. If you went through the bottom then it could leak and with pipe facing up, it'll be easier to suck in more junk.

[sasktrini]

I like that idea.  If I ever get adventurous and into plastic welding, I would be inclined to open a tank and weld baffles in that would keep grease and sediment away from the pickup... so it would accumulate near the tank's drain.  What about, say for example your tank is 8" deep... use a hole saw to drop in and weld a 7"  length of PVC (or matching plastic) pipe, and seal the top with a cover feeding in a 6" pickup tube?  Wouldn't that keep stuff out?  Then could run that through a pump and tankless water heater.  Thoughts?

[circleD]

My post got deleted so here's a summary and I'll do a diagram. 1" hole in top of tank. 1" pipe till it almost hits on bottom with a plug on inside of pipe or it want fit and drill 1/4" holes in the 1" pipe from the bottom and 3-4" upwards (strainer). Put a tee with 1" openings on top with the tank pipe in the middle one. On one side put a 3/4" male thread OR HOW EVER you can get a hose pipe to hook up on and cap it with a screw on cap. This is for back flushing the " pvc pipe filter" and to clean out tank. The last side opening can be capped and what ever size of hose you use drill through the cap and push the pump hose down into the tank through the 1" pipe interior. Seal everything up with epoxy. Some farm chemical tanks have baffles and multiple ports if you want a bigger tank.

[ibdilbert01]

They already do this in Boats, but as Kev said, the units are big and the cost for the maintenance is high. 

One thing I've thought about doing is capturing the condensation from the AC and routing it into the water supply tank. 

[tiinytina]

Another issue would also having a separate dedicated pump/tank/pipes just for shower to toilet.  doable if room.  In Gone's case the shower drains straight into the grey tank which is directly below it so no room to repipe anything.  my 2 cents.... :-)
tina

[sasktrini]

I hear you... retrofitting something like this would probably mean replacing one grey water tank with two that could fit in the same space.  But if you have access, the idea of a "light grey" (recycling) and "dark grey" system intrigues me.  Plus you would not get food mess coming up from the shower drain when the tank fills.

So...
Freshwater tank & pump 1 -> hot water tank and sink faucets -> dark grey tank
Light grey tank, filter & pump 2 -> tankless hot water and shower -> light grey tank
Light grey tank, filter & pump 2 -> toilet -> black tank

I guess after seeing so many RV rebuilds, and contemplating my own, I wonder if I could do the same and incorporate some new ideas.

I would definitely be interested in seeing what would be used in a boat.  I hope you will agree though that I'm trying to contemplate a "clean" light grey tank.  Am I dreaming?  I am thinking a second tank, filter, pump and some plumbing re-routing is all it would take.  Hey, it's winter and freezing up here... I'm just brainstorming.

Thanks for the chatter... I'm enjoying this.

[Oz]

Cool thing about these vintage RVs... if you can dream it, one way or another... you can do it!

[DaveVA78Chieftain]

simple solution.  Place tap on bottom side of grey water tank.  Open tap to drain to fill 1 gal bucket.  Flush toilet with bucket water.  No fuss, no muss.  You would always have the normal fresh water flush as backup.  Of course if your rig is like mine, the shower drains to black not grey so only kitchen sink water is available.   

I wonder how the wife would react to that?   D:oH! Hmm.  Glad I have the fresh water back up