Thread: Solar Hot Water heaters

Here's my 10 cents worth. Silver soldering(brazing) copper to copper. Use 15% silver brazing rod and you dont need flux just make sure pipe is clean (use steel wool or equivalent scourer).

Air to water heat pumps: These are quite efficient but careful on the brand. They are basically an airconditioner on reverse cycle but cheaper ones don't last. they have an EER (energy efficiency ratio of 3 and above which means roughly 1 k/w of electricity for 3 k/w of heating.
https://www.daikin.com/products/ac/lineup/heat_pump/

You really need to heat the water to 70°C to disinfect the water. Legionella and most other bacteria can survive in 60°C (140°F) water.
Legionnaire's Disease Outbreak Warning In North Thailand - Thailand News - Thailand Visa Forum by Thai Visa | The Nation

You need a thermostatic mixing valve to lower the temperature on the outlet of the tank which mixes cold water with 70°C water which lowers the water temperature to prevent scalding.

An alternative is to use your existing airconditioning unit to make hot water, although it will only work while the A/C is running.
https://techcrunch.com/2011/06/12/ai...-water-heater/

I'm lazy so I would just have a solar electric panel installed. then I can just use a conventional electric hot water storage unit.

Less than 1 year ago, I had this idea. It never materialized.
Our home is modern, 2 level, 400sqm, with all the latest insulating devices. Q-Con, CPAC etc. BTW, Norton was our guide and advisor.
Good luck with your concept.

Originally Posted by Doisaket

Hi All,

Just wanted to see if anyone has an update on this subject? I am building a home and looking for recommendations on brand, model and local retailer.

Every larger construction dept. store (in Ch.M. plenty of them) has got it - with different brands and prices.

I had a Solahart hot water system it run great for 23 years,then the tank developed
a leak,a new Solahart are expensive now,and you have to buy a whole new system,
but it was only the tank that needed replacing.

So Googled Solar heating, and at top was Chiang Mai Solar, so I phoned the company
it is owned by a German guy,he was very helpful,and he was able to supply the tank only,the tanks are of good quality and made in Greece,he manufactures the panels
himself,which keeps the costs down, so for taking the old SolaHart tank down,it weighed a lot more than when it went up,must have been filled with sediment,install
new 200 ltr tank,the biggest he had in stock at the time,but can supply bigger sizes,
make a aluminium stand to fix tank on,took them 2 days,as getting the old tank down from 2 story house not easy at all,so the cost of new tank,fittings,labour, came to
32,000 THB.
I would recommend anyone building a new house,install Solar water heater,in the
long run it will pay for itself,and the convenience of having hot water at every sink,
bath if you have one,and shower,the water gets scalding on hot days like we have been having, theres maybe 3-5 days a year when the water does not get hot,but you
can have heater fitted,for those days .chiangmaisolar.com ,knows what he is doing,
Dont be tempted by those cheap Chinese made water heaters ,they don't last.
regards Worgeordie

Good info. I'll get the missus to stick her neck in there next time we pass by.

Looks good.

"Solar Water Heating

Chiang Mai Solar offers different economical solar water heating systems.

Flat Panels are reliable, quick to install, almost indestructible and maintenance free; for small and medium households.

Heat Pipe Absorbers are an all weather high tech solution for large scale commercial systems; self-regulating, high performance, with electronic controller and forced circulation.

The Pool Heating Absorbers are especially developed for heating swimming pools and large Jacuzzis"

Chiang Mai Solar | Home Page

any idea for a solar heater for a washing machine only ?

probably 15 -20 gallons ,

I am thinking 3-4 plastic tubes at an angle for gravity feed ,
connect the tubes at the base with an on/off drain
and at the top where the water hose is connected ,

I do not mind "caveman" quality as long as it works,

and its not that hot here near the beach in Los Angeles , 70-75F ,
so the water needs to heat for 3-4 hours before using.

And will the plastic pipe leave a smell on the clothes ?

thanks for your ideas

Here is a simple one I found on Google from Mother earth news

A Portable Solar Water Heater



You start with a car or truck inner tube , add some fittings , fill with water and stick out the sun

I am sure we can think of a few more things like a Temp gauge , maybe a pump

only thing I worry about is that it might get TOO hot to take a shower and also how long before the rubber smell goes away.

Any ideas ?

Originally Posted by oldcarguy

any idea for a solar heater for a washing machine only ?

probably 15 -20 gallons ,

I am thinking 3-4 plastic tubes at an angle for gravity feed ,
connect the tubes at the base with an on/off drain
and at the top where the water hose is connected ,

I do not mind "caveman" quality as long as it works,

and its not that hot here near the beach in Los Angeles , 70-75F ,
so the water needs to heat for 3-4 hours before using.

And will the plastic pipe leave a smell on the clothes ?

thanks for your ideas

Just get a modern washing machine that heats the water, too easy??

"Pressure regulation by placing a weight on the tube."

25 years ago I saw a large rubber ball that you would fill with water for your campsite , it had a simple cart to move it around ,

the water was also pressurized from the city water pressure so you had
a warm shower after it had been in the sun a few hours......

Never saw them for sale in the shops , probably went to the wrong shop

But an inner tube could also be under water pressure so that it would spray

But it can also get heavy real quick if you use a big tube !

You only need about 5 litres of water for a quick shower, that's 5 kilos

Originally Posted by ENT

You only need about 5 litres of water for a quick shower, that's 5 kilos

yeah but really 15-20 liters for a decent not so quick shower

and more for the clothes washer......

Then build your own solar hw panel out of a sheet of ply, styro, reflective insulation, a grid of T joint (plus 2 x U-joints) connected lengths of black alkathene (2.5 inch di.), running upwards along the insulated board, put a timber frame around it with a couple of holes in the sides for inlet and outlet pipes, with a glass or plastic cover over that. Make sure you have space between the pipes and the cover.

Connect to hw tank via a one way valve to prevent backflow at night and connect to cold supply via a tap at the base of the panel.

Fasten that to your sloping roof or stand up on the ground at a lean facing the sun.

Job done, and a panel at 3 ft x 6 ft you'll have more hot water than you'll need.

Originally Posted by ENT

You only need about 5 litres of water for a quick shower, that's 5 kilos

How????

Ive had to take showers with bottled water in some of my previous work areas and this isnt possible

We just talking about hot water and then mixed with cool water to produce a shower thats like 10 liters or something?

Even 10 liters is hard

A 20 litre litre solar shower bag like this is a bit awkward to haul up at times after heating on the ground or roof of your car/van, so half full at 10 L is easy to lift up for a quick shower for two on the road, no cold water mixing and turn off while soaping before.

As kids in India during water shortages we were allowed about a litre each for a wash down, cold water at that!

^ Well no doubt it 'could be done' while trying real hard with 10 liters, turning off the valve whilst lathering and flipping it back on to rinse.

Same could also be done with a 55 gal drum painted black on a stand, gravity feeding a shower.

Anyway haven't looked at the whole thread I just assumed it was about 'solar' as in the paneling used on rooftops to heat water. Sorta-kinda the same thing with the black 55 gal drum/bag.

Love me a hot, lazy shower

There's all sorts of tricks for a shower in the bush.




A "Thermette" heats water fast, boiling in a few minutes.
I'd use a single dry pine cone to boil a full one, economical as hell.

You can cook on top too.




How it works.




Back in the day, every cocky and his dog had one.


On cloudy days we'd mix the hot water in a third of a bucket of cold water before pouring the mix into the solar bag, pouring scalding hot water into the bag successfully's nigh on impossible without scalding yourself, like filling an old rubber hot water bottle.

looking at google for "Thermette" also brings up Kelly Kettle ,

since I am not a camper / backpacker guy I never knew about them ,

but they look pretty interesting , amazing they can boil water with a few twigs etc

Thanks for posting that info

An old car radiator with a cold in hose and a hot out (at the top end) placed on a rack above a fire will get you lots of hot water in a hurry.

Just make sure the flames don't reach the radiator itself while it's empty, the solder will melt and the thing will leak.

Not tried it, but have been told that a radiator can be used as a solar panel if it's painted black and laid on some reflective foil at a slope facing the sun.

Camped up at one location, a long run of black pvc pipe was run up the hill along a fence line to get water up to the camp. After mid morning in summer the water was hot as could be, hot enough and plenty enough for a shower, the cooler water was down hill at the lower end.