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end80 20-08-2016 01:36

Solar hot water
 
I came across this video yesterday while considering methods of providing hot water on my Grampian 26 for a shower.. Http://youtu.be/dG2HK9JsAjw
Its a solar and pressurized hot water heater designed for campers to put on the top of their vehicle.. Its a DIY project based on a commercially sold product, which this guy details clearly in his video for a very moderate expense in parts (well under $100) His design provides about 6 gallons of hot water.
I contemplated on installing this contraption on the cabin top.. I posted about it on a live aboard Facebook page, and someone suggested to mount it upright "in place of a wiser pole on the front of the mast. Hand pump water into it, sun warms the water, then gravity feed where ever you need it."
This too sounded like a good idea..
What do you all think?
http://youtu.be/dG2HK9JsAjw

deblen 20-08-2016 05:09

Re: Solar hot water
 
Quote:

Originally Posted by end80 (Post 2193230)
I came across this video yesterday while considering methods of providing hot water on my Grampian 26 for a shower.. http://youtu.be/dG2HK9JsAjw
Its a solar and pressurized hot water heater designed for campers to put on the top of their vehicle.. Its a DIY project based on a commercially sold product, which this guy details clearly in his video for a very moderate expense in parts (well under $100) His design provides about 6 gallons of hot water.
I contemplated on installing this contraption on the cabin top.. I posted about it on a live aboard Facebook page, and someone suggested to mount it upright "in place of a wiser pole on the front of the mast. Hand pump water into it, sun warms the water, then gravity feed where ever you need it."
This too sounded like a good idea..
What do you all think?
http://youtu.be/dG2HK9JsAjw

Fine-as long as you sail into the sun most of the time! just kidding:biggrin:
It probably wouldn't be as efficient if vertical.

Consider this-you may be able to make it more compact if you use several runs of smaller ABS pipe with U bends or elbows & still end up with same volume of water.
I note that the comm. built model uses a 15-17PSI radiator cap as a pressure relief. Probably not a bad idea to install some form of pressure relief valve & safe drain. Look into relief valves for home furnace,hot water heaters,etc.

Interesting project. Hope it works out for you. / Len

svHyLyte 20-08-2016 06:30

Re: Solar hot water
 
Solar heated "Sunshowers" have been around for 50+ years. Tie one on your deck and in a few hours of less you have hot-sometimes needing a quart of cold-water for a "Navy" style shower.

https://i5.walmartimages.com/asr/b78...0&odnBg=FFFFFF

If "gravity" pressure (e.g. from hanging on your boom or halyard) isn't enough, dump the contents into a garden sprayer, pressurize, and you're in business.

sparrowhawk1 23-08-2016 13:38

Re: Solar hot water
 
PVC is an insulator and if it's vertical it will heat up slowly. I bought a solar shower every year for probably 20 years, they tend to degrade but they're very efficient and if you hang them up on the Mast you can get sufficient pressure ( add extra hose for inside shower) . one of my projects is going to be to get a clear 3 - 5 gallon water bottle( the kind used for water coolers) and hanging it up on my mast with a hose going down to my head. Or maybe just leave it on deck and have an electric pump.

MarkJ 23-08-2016 13:52

Re: Solar hot water
 
Quote:

Originally Posted by svHyLyte (Post 2193321)
Solar heated "Sunshowers" have been around for 50+ years. Tie one on your deck and in a few hours of less you have hot-sometimes needing a quart of cold-water for a "Navy" style shower.

https://i5.walmartimages.com/asr/b78...0&odnBg=FFFFFF

If "gravity" pressure (e.g. from hanging on your boom or halyard) isn't enough, dump the contents into a garden sprayer, pressurize, and you're in business.

This is the go!
I have it lying on the deck with the nozel going in the bathroom window. (Head porthole for nut cases)

They really are great as they give a measured dose of water - what u have put in. Portion control! :biggrin:

Sailorman Ed 23-08-2016 14:03

Re: Solar hot water
 
Get a 2 1/2 gallon garden sprayer, paint the outside black ( assuming a clear one to start), fill with water, put in the sun, wait 2 hours, pump up to pressurize, remove clothes and shower.

Added points if you splice in a hand held shower wand. Works great and much less than $100

sparrowhawk1 23-08-2016 14:49

Re: Solar hot water
 
1 Attachment(s)
Quote:

Originally Posted by Sailorman Ed (Post 2195942)
Get a 2 1/2 gallon garden sprayer, paint the outside black ( assuming a clear one to start), fill with water, put in the sun, wait 2 hours, pump up to pressurize, remove clothes and shower.

Added points if you splice in a hand held shower wand. Works great and much less than $100

Where can I spend my points. it's good to solar heat in very hot weather but when it's that hot you don't really have to heat it up. much better to have something clear. Or made of metal.

sparrowhawk1 23-08-2016 14:50

Re: Solar hot water
 
Quote:

Originally Posted by sparrowhawk1 (Post 2195977)
Where can I spend my points. it's good to solar heat in very hot weather but when it's that hot you don't really have to heat it up. much better to have something clear. Or made of metal.

Edit does using an induction heater powered by solar panels count as solar heating?

SailFastTri 23-08-2016 15:09

Re: Solar hot water
 
I've used sun shower bags and even in the 80's F and bright sun, they take a long time to heat and cool quickly. Not useful on overcast days or when rainy, and evaporative cooling is also a big factor even if they just get splashed in sunny weather.


Instead we heat a pot of water on the stove and add it to cold water in a sprayer like sparrowhawk shows above. Ours is from Duckworks Pump-up Solar Shower .

Sailorman Ed 23-08-2016 15:34

Re: Solar hot water
 
1 Attachment(s)
Sparrowhawk - same one but we painted it black and added a nice wand with on-off finger valve. Sorry - could only find this small pic. Black paint adds a lot.

sparrowhawk1 24-08-2016 13:28

Re: Solar hot water
 
Sailorman, I understand painting it black makes it more effective but not nearly as effective as clear. But the problem with clear is it grows algae and the UV breaks down solar showers.

deblen 24-08-2016 15:42

Re: Solar hot water
 
I have done this using black PVC flexible tubing (commonly used as well hose).https://www.youtube.com/watch?v=Q-LJNsvpVKI

I have seen this done with black ABS DWV rigid pipe also.

Neither ABS DWV pipe nor PVC "poly pipe" are insulators when used for solar heating. They absorb the sun's heat & heat water very efficiently.
Painting them FLAT black makes ABS/PVC somewhat more efficient because it dulls the shiny surface & cuts down reflection of sunlight. Roughing up the surface with sandpaper,if you have the patience,would have the same effect as FLAT black paint.

Google "solar water heat PVC or ABS pipe.

I agree the little black bag works fine in sunny climes,is cheap & simple.
But that is not what the OP asked about.

You can buy solar water heating panels made from black PVC for pool heating,etc. I had one & it worked fine.
The biggest problem is loss of heat at night or cloudy days.You must stop the water flow thru the panel during these times or panel will act like a radiator & will cool the pool water.

Len

Franziska 24-08-2016 15:55

Re: Solar hot water
 
Len,

if you have a small photovoltaic powered pump it should stop/reduce the flow at night or cloudy days.
Otherwise add a bypass valve.

By the way in colder climates add a drain to prevent damage from freezing.
Might be a thought to loop an antifreeze liquid and have it transfer the heat with a coil in the boiler.
Most marine boilers have this loop already as boats with inboard engines would connect their cooling water outlet to it.

Interesting project for those who like to shower inside and without restriction on waterflow.
The other solutions work too, but some people prefer a truly fixed solution.

Have fun,

Franziska

www.ladyrover.com

deblen 24-08-2016 17:02

Re: Solar hot water
 
1 Attachment(s)
Quote:

Originally Posted by deblen (Post 2196727)
I have done this using black PVC flexible tubing (commonly used as well hose).https://www.youtube.com/watch?v=Q-LJNsvpVKI

I have seen this done with black ABS DWV rigid pipe also.

Neither ABS DWV pipe nor PVC "poly pipe" are insulators when used for solar heating. They absorb the sun's heat & heat water very efficiently.
Painting them FLAT black makes ABS/PVC somewhat more efficient because it dulls the shiny surface & cuts down reflection of sunlight. Roughing up the surface with sandpaper,if you have the patience,would have the same effect as FLAT black paint.

Google "solar water heat PVC or ABS pipe.

I agree the little black bag works fine in sunny climes,is cheap & simple.
But that is not what the OP asked about.

You can buy solar water heating panels made from black PVC for pool heating,etc. I had one & it worked fine.
The biggest problem is loss of heat at night or cloudy days.You must stop the water flow thru the panel during these times or panel will act like a radiator & will cool the pool water.

Len

Edit: I meant Polyethylene pipe-not PVC-though I,m sure flat black painted PVC would work as well.
Attachment 130070

deblen 24-08-2016 17:03

Re: Solar hot water
 
Quote:

Originally Posted by Franziska (Post 2196731)
Len,

if you have a small photovoltaic powered pump it should stop/reduce the flow at night or cloudy days.
Otherwise add a bypass valve.

By the way in colder climates add a drain to prevent damage from freezing.
Might be a thought to loop an antifreeze liquid and have it transfer the heat with a coil in the boiler.
Most marine boilers have this loop already as boats with inboard engines would connect their cooling water outlet to it.

Interesting project for those who like to shower inside and without restriction on waterflow.
The other solutions work too, but some people prefer a truly fixed solution.

Have fun,

Franziska

www.ladyrover.com

Yes. Good points! Thanks/ Len


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