Recirculating Shower Systems

Hi Brian,

those systems excist ready to buy on the market.

I would divide them into two big groups. The closed loop system and the open or partially open loop system.

The closed loop system is (was) used in space craft or in the international space station ISS. This system recycles all fluids multiple times over and over again (and makes you meeting your morning coffe again, when having your soup at dinner ). It uses different types of mechanical filtering, reverse osmosys and distillation processes. Only dry remains of the loop are removed, dried and sterilized and stored or dumped into space in order to create a little falling star . I do not believe, you want one of those.

The other type is just an extension of the type of system, used in larger yachts and ships because of MARPOL requirements. All wastewater is led through a biological, thermal or chemical wastewater treatment system. The cleaned water is normally allowed to be pumped overboard, the remains are stored in an blackwater slush tank and released either at open sea or pumped into a land based facility, when in harbour. If the cleaned graywater would be sent through one more reverse osmosys plant, it could be used for any non potable water purposes. This system is used on remote and isolated research stations (desert and arctic) or mining facilities to extend their water reserves.

But why would you want to do that on your boat? Your boat floats in water . This additionally reverse osmosys plant, you need for the above system, can take its supply directly from the water around.

http://www.youtube.com/watch?feature=player_embedded&v=BCjH3k5gODI

The main cause of Legionella in household or boat water systems is the low temperature in the system. If you are keeping the water temperature in your system for energy saving purposes permanently below 60 degrees centigrade, those little friends can survive and grow in your system (as they do in the low temp central water heating system). I you increase the temperature in the warm water system once a week or month (depending where you are) for a day to above 60 degrees, Legionellas have no chance to survive. If you come back to your boat after weeks, have the boiler run at higher temp, recylcle the water and you will be safe. But a charcoal absorber and a UV sterilizer are always perfect components of any potable water system.

In earlier days, when reverse osmosys systems did not excist or were to expensive, ships had different water systems. Potable water was only used for cooking and drinking, water for laundry, shower and flushing toilets was made by destilating plants, using process heat (steam) of the machinery. Flushing decks and cleaning was mostly done with raw water. On my grand-grandfathers square riggers everthing, except drinking and cooking, was done with raw (sea) water and the supply of drinking water was limited per man and day.

Brian, these times are over. Neither my employeers, nor me and my family will go back to CONTIKI type sailing. We insist on an sufficient amount of fresh, clean and healthy water of drinking quality for onboard daily use. These above systems of yours, IMHO have no practical usage on a yacht or ship.

Except for the austere circumnavigating lonely sailor in his 30 ft wooden sailboot , modern yachts have sufficient fresh water supply, either by limiting their own endurance and using shore based refill facilities or having RO watermakers with the appropiate filtering and sterilization.

Large landbased resorts like hotels, are using water recycling to reduce their expensive fresh water consumption. But this recycled water is used for watering the garden or the golf course, not having the guests taking a shower with it.

What you want to do has been available for a long time but unless you are in a survival mode, why bother?

http://viewer.zmags.com/publication/...ad#/2e65b8ad/1

Hi Brian,

I built my first basic, but effective, recirculating shower in 1974, or thereabouts, when I was living in a very small trailer beside my first "under construction" ferro cement yacht. I learnt the essentials from that experiment and will soon be building my second more permanent shower. As has been made clear, a shower that does not solve the cleaning of the pipes issue is risky at best. The other main issue is that the water looses about 12 degrees C on each pass so it must be reheated. This design is for a 6 litre per minute flow rate with the water being reheated by an oil heated surface. I'm designing for up to 4 water changes per shower with each change being 3 litres for a max of 12 litres per shower over any duration that there is sufficient hot oil to reheat the water. I'm using circulated hot oil which stored at a max of 250 deg C, as this allows a compact storage of a lot heat in the minimum space.

However, by far the most innovation personal cleaning system that I ever encountered was created by a young French guy who tied up along side for a while in the seventies. This clever person created what I have talked about for years as the "bath tube". The benefits all came rushing home for me when I tried to take a shower mid Tasman in a friends very spacious shower on a Roberts 54. After sliding dangerously around for several minutes I resigned to sitting on the floor of the shower space with my legs rapped around a bucket of hot water for a sponge bath.

The bath tube on the other hand is body length tube about 700mm around which resides behind some furniture of the boat and is accessed through a hanging locker. My second ocean passage as a kid was on a ship in the days before stabilizers . This ship had a swimming pool which for the first week of the trip was emptied down to just several feet as the water was surging backwards and fowards with the action of the ship, much to the delight young kids like then self.

I instantly recognised the benefits of the bath tube for an ocean going yacht. When at sea one just pored in 5 or 6 litres of hot water, slid into thd tube with some soap, and the action of the yacht did the rest. It works especially well for washing clothes.

I take my hat off to that young Frdnch adventurer, wherever he may be.

Looks like the link in post #10 is incorrect, try this one to reach:

Dockwalk Magazine April 2009 "Part of the Solution"

Dockwalk - April 2009

I'm trying to picture it. Is the tube vertical or horizontal? How exactly do you get in and out of it? How do you add more water to rinse off?