Recirculating Shower with filtration system and hot water heater.

[Jonkistemaker]

I was wondering if anyone has installed a recirculating shower in their boat?

The ideal system would have multistage filtration, designated pump, and also have a small hot water heater that would reheat the already warm water.
I would treat this like a bath, shower first clean off, then add water to be recirculated, enjoy the luxury of an unlimited hot fresh water shower. Then at the end if you feel you need it rinse again and drain the system.

Might be a little complex but it sounds like a great way to save water and power if you want enjoy a luxurious hot shower off grid.

 

[dlochner]

Sounds like an expensive complex solution to a really minor non-problem.

How are you going to heat the water?

if you enjoy a luxurious hot shower.

Isn't this why they build marinas with nice showers?

 

[Jonkistemaker]

Ideally with a 1440w tankless heater. We usually spend several months on the hook in the Bahamas. Not having to go to the marina will save us lots of money.

We have a water maker but I figure it’s easier to manage the electricity needs for a 12 volt water pump than the energy needed to turn Salt water into fresh with our water maker

 

[dlochner]

deally with a 1440w tankless heater. We usually spend several months on the hook in the Bahamas. Not having to go to the marina will save us lots of money.

That's 120 amps at 12 v. Unless you plan to run the generator. Then you're burning diesel that is quite expensive in The Bahamas.

 

[Jonkistemaker]

That’s true! Heating water requires a lot of power. We have several methods to charge the batteries. But a 15 min shower would require 30 amps total. So with 400 amp hour battery it would use about 10% of our stored power. Our solar can handle recharging that.

To be fair an unlimited hot water shower isn’t realistic, but a very long shower might be.

 

[PaulK]

The filtration system sounds expensive, bulky, and awkward. Additional pumps, tubing and valves all over. Would it be cheaper to simply use mostly seawater, mixing it with hot fresh to warm it up? That would reduce freshwater usage overall and keep salt water out of the water heater.

 

[colemj]

We also spend several months each year in the Bahamas. The last thing I want is a long hot shower. Long cold maybe, but how long of a shower is wanted? I just want to get clean, and will lounge around in the sea if I feel like a soak. With 1500W of solar, a large battery bank, and 30gph watermaker, power and water isn't a limit for us - but I still don't want a long hot shower.

 

[Jonkistemaker]

“ Would it be cheaper to simply use mostly seawater, mixing it with hot fresh to warm it up? That would reduce freshwater usage overall and keep salt water out of the water heater. “

That could be a good idea. I hadn’t thought of that. You could have the cold be salt and warm be fresh. The problem remains with power needed to warm the water.

 

[Jonkistemaker]

but I still don't want a long hot shower.

Copy that. With a big water maker like yours and a dislike of long hot showers. It doesn’t seem like this would be for you.

 

[Tedd]

Excuse my ignorance, I've never sailed on anything longer than 26 feet. But aren't grey-water systems common on larger boats? Maybe not until you get to the 50-foot-plus range?

 

[dLj]

What would you filter? Soap, bacteria, particles (dirt), salt? To what level of filtration? If you are trying to bring the water back to essentially potable water you are looking at some serious filtration. How many gallons per minute would you need?
These would be my questions that one would have to answer to start designing such a system. If you aren’t doing this in real time, meaning a complete recycle while showing, then you would need storage tanks to hold dirty water while it’s filtered to then move to a clean water tank for use.
Seems mighty complicated to me.

dj

 

[Jonkistemaker]

Excuse my ignorance, I've never sailed on anything longer than 26 feet. But aren't grey-water systems common on larger boats? Maybe not until you get to the 50-foot-plus range?

My boat and I believe most cruising boats do under 50 do not have grey water systems. It goes directly overboard. Even at a marina, which can contribute to a lot of soap waste as well.

 

[Jonkistemaker]

What would you filter? Soap, bacteria, particles (dirt), salt? To what level of filtration? If you are trying to bring the water back to essentially potable water you are looking at some serious filtration. How many gallons per minute would you need?
dj

The Filtration would mostly be for dirt and particles. From my understanding soap is a big challenge for any filtration system. So the idea would be to take a short shower first where you soap up and rinse. Then switch over to the recirculating system. ( most of the time I am already coming into the shower from diving or surfing and am already very clean and don’t need soap anyway)

For filters I was planning on a 50 mesh pre filter. Then a 3 gal per min pump. Then 100 micron, 50 micron then 20 micron filters.
I would NOT drink this water. When I am done with recirculating the water I would pump it overboard.

The goal would be to have very little water in the recirculating system. ( I don’t have space and sitting water is going to get nasty.)

 

[Tedd]

From a quick look around the web it appears that removing soap from the water likely won't be practical. But your dual-mode idea will probably work--i.e., use the grey water for the wash part of your shower and then fresh water for the rinse off. Also, with a little extra plumbing you can probably use the grey water for flushing the marine toilet.

 

[Jonkistemaker]

Good point about the toilet! Thats a good idea.

 

[Leeward Rail]

Sounds like an expensive complex solution to a really minor non-problem.

Step 1 bathe in the ocean
Step 2 rinse with freshwater from a black bag hanging from the rigging.
Done.

No complexity, minimal cost, minimal environmental impact, no additional heat and humidity added to the boat.

 

[Shadowwalker]

Remember when all boats just flushed there toilets over the side? In many places it is illegal to put any gray water over the side. I can see this as a growing concern. Gray water tanks will so be required on all recreational boats.

 

[Jonkistemaker]

Remember when all boats just flushed there toilets over the side? In many places it is illegal to put any gray water over the side. I can see this as a growing concern. Gray water tanks will so be required on all recreational boats.

This system would definitely minimize the amount of water flushed overboard. When I have unlimited water at a marina I often feel bad taking a long shower and dumping it over.

 

[dLj]

Remember when all boats just flushed there toilets over the side? In many places it is illegal to put any gray water over the side. I can see this as a growing concern. Gray water tanks will so be required on all recreational boats.

Hope it doesn't happen in my lifetime. It's my understanding recreational boats are not on the list to control Grey water at least at this point. I wouldn't want to be forced to find space for Grey water tanks on my boat. That would be a major retro fit...

dj

 

[MikeHoncho]

Install a flow meter on your system. That is the best way to conserve water. It’s gives you an idea of how much water a shower takes and you get really good at being efficient. I have gotten a shower for me down to leas than 2 gallons, all fresh used. Filling a jug up with water until it gets warm the pouring it back into the tank is a significant way to save. I think a recirculating system is a poor way to overcome the issue. Plumbing in a salt water system to wash with then rinse with fresh would be more applicable.