DIY Solar Water Heater

[Bluedog225]

Yes. And when you put water into a hot system, caution advised.

Neighbor is a former Johnson Controls guy who installed a lot of industrial sized solar hot water for the army for a laundry facility. Said it was a dangerous mess. They ended up taking it out.

Not saying it’s a bad idea. Esp for an individual. I may do something like that myself.

 

[OzSolar]

My gut tells me that they are already of a lot people doing any one of several versions of batch water heaters already there in the Philippines. I'd ask my neighbors and coworkers. They will know much more than any of us keyboard warriors about what works best for you there.

 

[slowbutsure]

Actually I had forgotten about the solar water that I built about 25 tears ago. In this case I took a an electric water heater removed the insulation, painted it black and put it in wooden box with a glass top and pointed it towards the sun. I worked pretty good but didn't hold the heat very well overnight especially in the winter. In the Philippines losing heat at night wouldn't be much of an issue.
If uninsulated hot water tanks are available there then that may be the way to go.

If I bought a tank and cut a hole in it to fit an immersion heater with thermostat, is there anything else needed? In terms of safety in particular. The thermostat is usually pretty good I think.

 

[sparrowhawk]

If I bought a tank and cut a hole in it to fit an immersion heater with thermostat, is there anything else needed? In terms of safety in particular. The thermostat is usually pretty good I think.

I personally wouldn't do it because her in the states there's no need to plus it just adds more potential failure and safety issues. Are there no commercially available hot water heaters in the Philippines?

 

[slowbutsure]

I personally wouldn't do it because her in the states there's no need to plus it just adds more potential failure and safety issues. Are there no commercially available hot water heaters in the Philippines?

You can get heaters here but they are very expensive as a niche product. I could make one for 20% of the cost.

Immersion heaters have thermostats that work well. I’m the U.K. (where I am from) a heater tank just has an immersion heater with a built in thermostat. No other safety features. Of course, making it myself I would want to be extra cautious. I would want to add a second thermostat that cut the power if the water temp exceeded 80c. I’m sure such a stat must be available, I just haven’t looked for one before.

I could also paint it black and position it in the sun to preheat it and save some electricity.

 

[sparrowhawk]

You can get heaters here but they are very expensive as a niche product. I could make one for 20% of the cost.

Immersion heaters have thermostats that work well. I’m the U.K. (where I am from) a heater tank just has an immersion heater with a built in thermostat. No other safety features. Of course, making it myself I would want to be extra cautious. I would want to add a second thermostat that cut the power if the water temp exceeded 80c. I’m sure such a stat must be available, I just haven’t looked for one before.

I could also paint it black and position it in the sun to preheat it and save some electricity.

Here in the states water heater thermostats are readily available and are simply held against the bare steel of the tank. The one for a single element water heater should work for your application. It's likely the same thermostat as the lower one on a dual element water heater and the temperature is somewhat adjustable on them. If you're going to go that route then I would suggest keeping the thermostat out of direct sunlight as that are partially made out of plastic and the sun may cause it to rapidly deteriorate.

Another concern to be mindful of is pressure buildup. In the event of thermostat failures a pressure relief valve is cheap insurance against a catastrophic event that at best could result in an extreme amount of destruction to your property and and worst cost someone their life.

Thermostats and pressure relief valves are available on Amazon and I know at least for some items Amazon does deliver to the Philippines.

 

[slowbutsure]

Here in the states water heater thermostats are readily available and are simply held against the bare steel of the tank. The one for a single element water heater should work for your application. It's likely the same thermostat as the lower one on a dual element water heater and the temperature is somewhat adjustable on them. If you're going to go that route then I would suggest keeping the thermostat out of direct sunlight as that are partially made out of plastic and the sun may cause it to rapidly deteriorate.

Another concern to be mindful of is pressure buildup. In the event of thermostat failures a pressure relief valve is cheap insurance against a catastrophic event that at best could result in an extreme amount of destruction to your property and and worst cost someone their life.

Thermostats and pressure relief valves are available on Amazon and I know at least for some items Amazon does deliver to the Philippines.

Here in the states water heater thermostats are readily available and are simply held against the bare steel of the tank. The one for a single element water heater should work for your application. It's likely the same thermostat as the lower one on a dual element water heater and the temperature is somewhat adjustable on them. If you're going to go that route then I would suggest keeping the thermostat out of direct sunlight as that are partially made out of plastic and the sun may cause it to rapidly deteriorate.

Another concern to be mindful of is pressure buildup. In the event of thermostat failures a pressure relief valve is cheap insurance against a catastrophic event that at best could result in an extreme amount of destruction to your property and and worst cost someone their life.

Thermostats and pressure relief valves are available on Amazon and I know at least for some items Amazon does deliver to the Philippines.

Thanks. Yeah I’m thinning of cutting a hole in the bottom of the tank for the heater. Picture of kind of heater attached. Though if it was a horizontal tank it would go in the side.

Good point on the pressure release valve. If you can find one of those thermostats on Amazon and give a link that would be great, no worries if not. I like the idea of a backup thermostat.

 

[slowbutsure]

Still deciding whether to go electric or not. Yesterday I made a test thermosyphon non-pumped, non-electric heater to see how that went. What I found is that water only came out of the hot outlet if the storage tank was higher than the top of the heater. But then the hot water couldn’t reach the top of the tank, has to go in the middle. But then can’t tell if it’s circulating or not as it’s submerged. Ran out of sun yesterday. I have bought a non-return valve which I’ll fit today.

Am I missing anything? I haven’t enclosed the pipes yet with clear plastic. The water was getting hot though.

 

[Supervstech]

You can get heaters here but they are very expensive as a niche product. I could make one for 20% of the cost.

Immersion heaters have thermostats that work well. I’m the U.K. (where I am from) a heater tank just has an immersion heater with a built in thermostat. No other safety features. Of course, making it myself I would want to be extra cautious. I would want to add a second thermostat that cut the power if the water temp exceeded 80c. I’m sure such a stat must be available, I just haven’t looked for one before.

I could also paint it black and position it in the sun to preheat it and save some electricity.

A basic electric water heater is a niche product there?

 

[slowbutsure]

A basic electric water heater is a niche product there?

One that stores atleast 200L of water is, yes. A basic non-storage water heater, no. Most people here just don’t have hot water at all.

 

[sparrowhawk]

Thanks. Yeah I’m thinning of cutting a hole in the bottom of the tank for the heater. Picture of kind of heater attached. Though if it was a horizontal tank it would go in the side.

Good point on the pressure release valve. If you can find one of those thermostats on Amazon and give a link that would be great, no worries if not. I like the idea of a backup thermostat.

I don't know if I should be inserting Amazon links on here but a simple Google search yielded an Amazon hit right at the top of the list.

I just want to say that I understand the need to do as much as you can to save money, but if's there's anyway you can get a commercially made water heater and turn that into a solar water heater you will almost certainly save yourself a lot of potential headaches. And possibly money in the long run.

 

[slowbutsure]

A basic electric water heater is a niche product there?

One that stores atleast 200L of water is, yes. A basic non-storage water heater, no. Most people here just don’t have hot water at all

 

[Supervstech]

One that stores atleast 200L of water is, yes. A basic non-storage water heater, no. Most people here just don’t have hot water at all

Oh, good point, most of the world uses on demand water heating.

Around here 40 to 50 gallon tank heaters are the norm. (140-200 liters)

 

[KennyHendrick]

I've been living for more than a decade with a simple 48v array (has grown to 24 panels or 6 strings @ 48v) and simply wire the wires directly to the electric water heater.
*I never changed the ac thermostat for the dc one so if I ever forget to turn off the (almost instant) hot water, a breaker in the water tank does it for me (but now I will need to wait much later to take a shower pending the tank cooling down so that has been somewhat solved by a "system".

And get this, if you DON'T bother changing out your ac thermostat and decide to be lazy like me by leaving it in there, I've found it doesn't make a difference which wire I connect to positive or negative, it just works.

Typically, on a bright day, I can make my water heater go from cold water from our well to skin-safe shower water in about an hour (if 110v didn't burn up that water heater my 48v should last forever and ever as per the amps produced).

*****I also convert all ac hotplates to dc direct using the same exact 48v array! I also use an mppt controller as a DUMP LOAD which automatically shapes my day (never put your controller on a breaker as you might your appliances (water heater, hot-plate cookers, etc.); rather the controller that you use to charge your batteries needs to be connected directly to the incoming solar panels at the input of your breaker box (in my case there are now 3 instead of 2 wires in each of the breakerbox input bolt.

There's more! We even have 3 12v direct energy applications running our lights perfectly (even the open signs startup at dawn and turn off at dusk) I made videos but my website is banned by the military (or whoever has broad control of everthing conected to the internet) or else I'd bother to jot the site address here.
Good luck, if this isn't what you want then I hope it helps someone else.
p.s. I'm taking offers on the all-steel bus

 

[sumpower]

Don't know what the average daily temperature is where you are located, but we just used a rotomolded 600 liter black tank that sat on the roof. Water was hot enough for daily showers and washing dishes. If you are far enough south this system will work just fine. Only pump required was the one to fill the tank once a week.