How do I build a recycling shower?

May 7, 2010 9:02 PM

Calling water purification gurus! Help me with an off-the-grid water recyclin' shower!

So I've been put in charge of our Burning Man camp shower. I'd like to build a shower that filters and sterilizes shower runoff, so it can be safely reused. I wouldn't mind being able to handle well-strained kitchen greywater as well. All in all, it'd mean less water brought to the playa, less cleanup, and more showers!

I'm leaning toward this: SK103. Throw the "candle" end into the shower basin and let it wick up the water. The first ceramic filter gets solids and bacteria, and the second activated charcoal filter gets sunblock and other chemicals. This should plow through 3 gallons or so an hour.

The ceramic filter doesn't get all viruses, though. I've considered adding a homebrew UV purifier. It can handle about a gallon per minute but uses 0.75A to run, so I don't particularly want to have it going all the time.

As far as the actual shower part, I'm planning on using a 12V bilge pump off a switch to pump up to a shower nozzle. For simplicity, the same 12V battery will power the pump and the UV light.

First off, is this a reasonable project and is it safe? Is it overkill?

Secondly, how do I reconcile the two different speeds of the filtering (3GPH) and the UV (60 GPH) while minimizing power consumption?

Thanks!

posted by cr_joe to Technology (6 answers total)

You may be of a different view, but I think your set-up is way overkill. Since I would imagine that water is at a premium at Burning Man, you could go with something like this that would probably use even less water than your set-up, be a lot less likely to break down, be less expensive, and take a lot less of time to troubleshoot.

I think if you created your project, you would have to apply suction to the water filter after a few uses, regardless of the fact that it is marketed as a siphon filter. If you did have to apply suction, that would require you to continuously run your pump motor and sync the filter rate with the pump rate in order to avoid burning out your pump motor or blowing out your filter. You would also have to adjust the pump rate to compensate for the increase in its resistance that would occur with use.

I think your plan would work, but it would be a pain in the ass to use.
posted by 517 at 9:24 PM on May 7, 2010

Joe

That's a real pandora's box you just opened with that question. It really depends on how much you want to use it, whether other people will use it, how much they have to change their behaviour to use it, can you store the water and do you have any liability if other people use it and are injured or get sick.

My company makes recycling showers and is planning to launch them in Australia next year and in the USA next year or 2012.

To make them compliant with building codes, electrical and hygiene codes is difficult and expensive.

If you are making one just for you - your plan sounds like it will work to a basic level but you will find that the filters clog very quickly.

Please feel free to contact me if you want to find out more, or just contact me when you have built yours and let me know how happy you are and how well it works.

Good luck and enjoy the project.
posted by Nick C at 11:51 PM on May 7, 2010

How will you charge the battery?

In honor of the spirit of burning man, you probably ought to make it human powered. Hook up a generator to a bicycle, and anyone who wants to shower powers it for the next guy. Or something.
posted by gjc at 4:35 AM on May 8, 2010

Response by poster: Thanks for the advice so far!

We will have access to 110V, so we can charge the battery - close enough for a brief stroll, too far to just run a cord.

Building codes don't exist. "Liability" also an interesting point - there's a general understanding that there are some dangerous things out there and by participating you take on that risk, but on this project I'd rather err on the side of caution than run the risk of anyone getting sick from waterborne pathogens.
posted by cr_joe at 7:14 AM on May 8, 2010

Response by poster: Which is not to say I'm ruling out doing this. ;)
posted by cr_joe at 8:09 AM on May 8, 2010

I think you have overkill here. The water isn't for consumption-just washing so you don't have to get it perfect. I would make use of the resources at hand for burning man, sand and sunlight. Use a sand filter in either 55 gal drums (really effective but big and heavy) or a series in 5 gal plastic buckets (in either case use food grade containers). Then use clear tubing (glass would be awesome but fragile) snaking back and forth over a black surface (i am thinking painted plywood but a dark rock would work) for the UV decontamination, as a bonus you will probably get significant heating of the water.

To prepare the sand use a sifting screens of progressively finer mesh to get out the big stuff and the little stuff. you want to use the stuff in the middle (no gravel and no clay either). There are instructions on line for how to build a DIY sand filter that will usually make water safe for consumption. If you really want clean water flocculate it first. Clear poly tubing would probably work for a few days before UV degradation gets it for the UV stage. All the material you need will fit inside the barrel(s) and the rest you find on site. I would even use a cut down barrel for the shower floor to collect the water. BTW the barrels can usually be found at places that prepare food (ice cream factories usually have a ton around), soft drink bottlers or the like and can usually be had cheap and sometimes for the asking.
posted by bartonlong at 9:46 AM on May 8, 2010