Recirculating Shower System(s)

Discussion in 'Boat Design' started by brian eiland, Aug 5, 2013.

  1. rwatson
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    rwatson Senior Member

    And you lived ??? :)

    That idea worked in the old west and in victorian england in the old days, and most of the third world today.

    Come to think of it - the death rate was so much higher then as well :confused:
     
  2. philSweet
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    philSweet Senior Member

    Brian, its really tough to guess how far to take this without some cost comparison data. I had written up a response a lot like Petros's and then deleted it. There really are very serious health concerns just with the prospect of adding a recirculating plumbing path into the system.

    So what is the cost of water. RO is the cheapest and can run from about $2 for 1000 ltr to five times that. It can be more if the genset is run primarily for water as opposed to being load managed. Knowing what we are trying to save is pretty basic to the problem. One possibility is to just filter the water and UV sanitize it and meter it to the front end of the the existing RO system. It will improve efficiency by lowering the necessary pump pressure for a given rate of production. Or use a separate RO system employing retired membranes running at greatly reduced pressure.

    If you look at the "therapeutic experience" aspect of the shower, a lot can be done. The warm-up phase, where the shower is run to get the humidity and comfort heat up, can be 100% recirculated and makeup heat added by the recirc system. Close the drain and turn the tap on. This would divert drainwater into the recirc system. The shower would run at distribution pressure and charge the recirc system. Say 3 l/min at 125 degrees F for 90 seconds with full recirculation heat once the recirc system got water. (I think everyone is being a bit wistful about the amount of reheat required. You need gobs of it.)

    The system is storing 5ltr and reheating it while you open the drain and do the soapy business and are running at distribution pressure and consuming/conserving water as you choose.

    When the rinsing is done and you want a better shower, close the main drain and turn on the booster pump.

    A high pressure pump kicks in and you have a 50-60 psi supply at 6 l/min using 1.5 l/min supply and the rest recirculant. You would then have a really nice shower.

    Some technical challenges -

    1. Gaining temperature control as you turn the booster pump on and off. I suspect this is the most costly function to achieve.

    2. Automating the end of cycle to heat and purge the last bit of water.

    3. Booster heater. Basically an on demand heater of fair size.

    Some of the mechanicals would be similar to a clothes washer or commercial dishwasher with cycle controls and temp mixing valves and heating systems. Wouldn't it be nice if the shower could share these mechanicals with the clothes washer on board? You could improve both by splitting the costs and weight and bulk between the two systems.
     
  3. rasorinc
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    rasorinc Senior Member

    Iodine will purify water for drinking. just a couple of drops to a gallon. Would also work on used water for showers. Do they still make Iodine???
     
  4. rwatson
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    rwatson Senior Member

    Great analysis and conclusion.

    It takes me back to the time as a grubby teenager in a grungy flat with no clothes washer, and no money for a laundromat, when I used to put my washing in the bottom of the bath while I showered, and stomp on it while I washed myself. Then I would rinse all the soap off me and the clothes before I got out.
     
  5. brian eiland
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    brian eiland Senior Member

    WHAT are you talking about??
    Do you defecate in your shower?



    I'm not following your train of thought here or something? What grossed me out? Its not oblivious we are talking about the same thing?
     
  6. brian eiland
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    brian eiland Senior Member

    I'll have to reread this again,...but doesn't sound a lot like the Quench system I posted about in posting #4

    This doesn't sound overly complicated to me? I even wonder about the need for a complicated (if that is being referred to) 'sanitization system' on the recirculation side.
     
  7. rwatson
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    rwatson Senior Member

    Hey, its been done - by Australians :)

    But .... ( dramatic music here ) they dont advertise any prices !!!!

    http://quenchshowers.com/


    "How does it work and does the process of showering change?
    As the process of showering is different for everyone the Quench method is based on the following:

    Simply enter the Quench shower and begin to efficiently wash your body using soap & shampoo and rinse off thoroughly. Once the soapy water has disappeared down the drain, push down the drain cover and allow the reservoir to fill (approximately 4 litres (1 gallon) of clean temperature-controlled water). Turn the shower off.

    Activate the Auto-Mode and the water will re-circulate continuously through the shower for as long as you like.

    The water is filtered, pressurised and heated to the temperature that is set by the user at the control panel – using only 4 litres (1 gallon)!

    When you finish simply pop the drain cover up (emptying the reservoir) and step out. Next activate the Sanitize–Rinse cycle and the entire system will be effectively sanitized and rinsed leaving the system in its original hygienic condition ready for the next shower."


    http://quenchshowers.com/faqs/
     
    Last edited: Aug 11, 2013
  8. brian eiland
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    brian eiland Senior Member

    I guess I am thinking of a slight modification to their system for simplification purposes. I might hope to eliminate that last 'sanitation step of theirs?

    I was thinking of a system that would have two 'control levers', one labeled "Wash", one labeled "Massage"

    In the 'Wash' mode the shower would draw water from the water supply tank and drain it overboard as you took your 'washing with soap' shower.

    Following that cleansing one might move to the 'Massage' mode. Here the small 'massage supply tank' would fill from the water supply and proceed to recirculate as long as you wished for that therapeutic portion of the shower.

    At the end the 'massage supply tank' would be drained overboard,...or perhaps diverted to a black water tank for toilet flushing, etc.

    Hot water for either wash or massage would be via the very efficient on-demand, instantaneous style water heaters.
     
  9. michael pierzga
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    michael pierzga Senior Member

    But you will still be using the same water collection plumbing ? It will be contaminated.

    I suppose you could use two shower drains..one gray water one recirc water. Even then I fear that the recirc water will become contaminated
     
  10. brian eiland
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    brian eiland Senior Member

    Don't understand your plumbing.?

    There is ONE supply line from your onboard water tanks that feeds your shower, and can fill the small 'massage tank'...check valve so no back fill.

    To simplify things there is ONE drain line...to drain the shower, whether you are taking a soapy shower, OR if you are emptying the 'massage tank' after its use.

    Sorry to confuse you with the possibility of placing a 'Y' in that single drain line so as to possible use some of that 'drain water' for flushing toilets or whatever, rather than just draining it overboard.
     

  11. nimblemotors
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    nimblemotors Senior Member

    Another consideration is recycling the heat from the water before disposing it.
    I think a good plan is to use salt-water during washing/rinse and then fresh water recycled for 'hydrotherapy'. Using a heat exchanger to heat the fresh water from the salt water before disposing of it should save a lot of energy.
     
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