Recycling shower DIY

[partyvi]

Hello.


I am working now on recycling shower design for my boat.



First, the idea to save water but do not overthink about filtering.

Technically shower will work in two modes clean water just normal shower dumping water over board and recycling water shower to get warm up and have fun.



starting points:

I want to use existing on board pressurized cold and hot water on start. and clean shower mode.

Then use hot water only to "reheat" recirculating water, just add hot water to recycle and dump some recycle water over board.


A main idea is to use small couple gallons non-pressurized tank and mixing bowl and run one independent pump to feed shower head and one (little bigger capacity) to suck water and feed it back to tank.


Filter is not shown, but main idea to make virtual bath, not to reuse water over and over. I expect to be able to use no more than two gallons for nice 10 minutes soaking shower.


More information about my project is here:
https://irwin34.blogspot.com/p/recycling-shower.html





What do you think?

[thinwater]

Originally Posted by partyvi

Hello.


I am working now on recycling shower design for my boat.



First, the idea to save water but do not overthink about filtering.

Technically shower will work in two modes clean water just normal shower dumping water over board and recycling water shower to get warm up and have fun.



starting points:

I want to use existing on board pressurized cold and hot water on start. and clean shower mode.

Then use hot water only to "reheat" recirculating water, just add hot water to recycle and dump some recycle water over board.


A main idea is to use small couple gallons non-pressurized tank and mixing bowl and run one independent pump to feed shower head and one (little bigger capacity) to suck water and feed it back to tank.


Filter is not shown, but main idea to make virtual bath, not to reuse water over and over. I expect to be able to use no more than two gallons for nice 10 minutes soaking shower.


More information about my project is here:
https://irwin34.blogspot.com/p/recycling-shower.html





What do you think?

I've puzzled on this a few times (teenage daughter). There are complex commercial systems. But in the end, we decided that quick showers were just fine. Recycling doesn't actually save water vs. a quick shower, because you have to pitch the first flush anyway. Otherwise the not-clean water with soap in it will go septic before you next shower. Not a simple problem.


Good luck.

[wholybee]

My brain hurts from the complexity. I think this should be achievable without a tank and without the microcontroller, and so many valves.

What I think you really want is a supply line to the cold supply direct without using the pressure pump(pressure pump would still be needed to pressurize the hot water heater). There is a selector valve to select from that cold water line or the recycle return line. And all you need is for that valve to automatically switch to the recycle line if water is available there, and if not default to the cold supply line. It could probably be done with some sort of 3 way check valve. Then a pump behind that to draw from the output of that 3 way valve, to your hot/cold mixing valve the user uses to set the temperature (just a regular shower tap, probably) The drain drains into a sump. The sump has 2 levels, the lower level recycles water to the first selector valve, and the pump at the higher level pumps overboard. Probably could do that with a single pump and some sort of float operated valve.

So you then have:
2 pumps
2 float/check valves
Shower sump
Temperature controlled with standard shower tap.

No microcontroller
No need for your 7 electrically operated valves.

You need to figure out the float/check valves, but if you can't find something off the shelf would probably make something. For example, there are valves that will shut off if air reaches it, but will pass liquid.

[sv_pelagia]

Previous owner of our boat put in a recycling shower (essentially, shower sump pump routed to shower head).



I think we tried it once. Yuck. And not warm enough.



One can be very frugal with water with handheld shower. When water really an issue, we use a pot of water, washcloth, and sink.

[partyvi]

Originally Posted by sv_pelagia

Previous owner of our boat put in a recycling shower (essentially, shower sump pump routed to shower head).



I think we tried it once. Yuck. And not warm enough.


One can be very frugal with water with handheld shower. When water really an issue, we use a pot of water, washcloth, and sink.

First, I plan to replace part of recycle water with hot water from boiler during operation to do shower warm.

Two. System will be dry with air after each use,

Three, you always may flush it with alcohol, vinegar or bleach one in time or even automate this.

And talking about sump… my system has has no sump box. Actually it pumps water and air if lack of water to tank which will be pumped completely, out when you done. After some comments I even think to flow air to dry tank it to dry to avoid growing crap there. It will require to make two much bigger vent s but doable.

Also, system do not make recycling mode mandatory, you will be able to use it just as short shower.

[wrwakefield]

I believe most shower water is wasted running it until hot, then mixing to the desired temperature. All this before the average user starts showering.

On my past 3 boats I added a valve [time release push button is best…] that recirculates the hot water back to a water tank [typically via a T inserted to the tank vent] until it is hot at the shower; thus saving what is typically the majority of waste water from a sailor shower.

To save even more water, install a thermostatically regulated shower valve [<US$100 on Amazon] and the shower temperature starts out perfect [i.e., no scalding and no water wasted adjusting manual valve(s) for the perfect temperature.]

Both of these approaches work great and are relatively cheap. I wouldn’t be without them.

FWIW

Cheers, Bill

[wrwakefield]

Originally Posted by wrwakefield

I believe most shower water is wasted running it until hot, then mixing to the desired temperature. All this before the average user starts showering.

On my past 3 boats I added a valve [time release push button is best…] that recirculates the hot water back to a water tank [typically via a T inserted to the tank vent] until it is hot at the shower; thus saving what is typically the majority of waste water from a sailor shower.

To save even more water, install a thermostatically regulated shower valve [<US$100 on Amazon] and the shower temperature starts out perfect [i.e., no scalding and no water wasted adjusting manual valve(s) for the perfect temperature.]

Both of these approaches work great and are relatively cheap. I wouldn’t be without them.

FWIW

Cheers, Bill

The other thing you can do to conserve water is to put a mixing valve at the water heater.

Typical scenario: The water in the tank is >170°F after an afternoon of motoring.

Hot water >~120°F is too hot to wash your [my] hands in…

If it comes to the tap at, say, 120°F, then it takes less time and cold water to mix it to the desired temperature. And once again, a thermostatically controlled faucet at the sink virtually eliminates temperature adjustment time [i.e., running unused water down the drain]- as well as providing consistent water temperature- at least until the hot water is cooler than the set temperature.

All FWIW

Cheers, Bill

[Greatest Lakes]

Interesting idea, but simply using a water maker would likely take up less room, be less complex, have more uses, and be cleaner. You really don't want to risk drain water ever reaching any part of your freshwater system. Bacterial growth is almost impossible to really clean from the inside of vinyl or plastic tubing. You also don't want to accidentally contaminate any tanks.

[S/V Illusion]

Great way to expose everyone on board to shared pathogens just to save ? See hepatitis, norovirus, E. coli, …

[Orion Jim]

Recycle shower water…uh, no thanks

[ggray]

Originally Posted by wrwakefield

On my past 3 boats I added a valve [time release push button is best…] that recirculates the hot water back to a water tank [typically via a T inserted to the tank vent] until it is hot at the shower;

Cheers, Bill

This is what I’ve done along with taking “Navy showers”

[markxengineerin]

I have met one cruiser using a recirculating shower system. I always wondered about the ability of the filters to catch EVERYTHING bad, and about how much water is wasted in rinsing out the filters. With my watermaker system, I have to rinse the pre-filters with fresh water after every use, and store them dry, otherwise they plug up quickly and start to smell. I imagine the filters in this system having similar requirements, if not worse, because you need sub-micron filters to block the nasties.
Alcohol, vinegar, bleach are all possible (if the filters are ok with this), but that's a lot of alcohol, vinegar, and bleach to be carrying around.

Many have gone through the mental exercise of planning a system, but almost nobody builds them... for a reason.

[thinwater]

The only systems that seem remotely practical are ones that use fresh water through the cleaning cycle and only switch to recycle after the person is clean. In other words, a long, hot shower. But I think most of us are happy to just get out of the shower once we are clean, so there would be no water savings. I never take long showers at home. If the purpose is the process of cleaning conditioning, and rinsing long hair, since you are still using fresh water there is no savings.


The only system that makes sense to me is one with a dry sump and no filters other than the floor hair catcher(they'll just get nasty). The shower is taken in the normal way, with water discharging as you go. By the time you are sufficiently clean the shower pan and sump (nearly dry) is warm. You switch a 3-way valve, redirecting the water to the head, perhaps combined with a thermostatic valve. When you are done reset the valve and turn off the water. Since the first flush will be discarded on the next use, there is no need to flush, but you could switch the valve back for a 10 second flush. I considered setting this up on my last boat, since most of the pieces were already in place (all I needed was the 3-way valve). But really, what purpose does it serve, since you are already clean? Even my long-haired daughter thought it was a waste.



Home systems, in desert climates, sometimes use gray water for irrigation. Seems workable. Progressive desert cities, hard pressed for water, are going to double pipe systems, one being treated wastewater from the city for irrigation. But that is a whole nuther' topic.

[Cheyne]

The answer to the question that was never asked.

Cheyne

[LakeSuperior]

Do the math...what are you really saving. Add another fresh water tank if you are looking for a project.

Methinks you will have enough to maintain and repair without adding this complexity to your life.

Even with a really good filter there is a serious ick factor on this idea.