Today we are going to see three different ways to create a homemade solar water heater, both the version of 100% recycled materials, to supply our house with hot water, and two others based on materials that we will have to buy (if we do not have them at home). ).
Homemade solar water heater for free water with PET bottles
Let’s look at this example first. A few decades ago, José Alano, a retired Brazilian mechanic, was inspired by the collection of plastic bottles (PET) and used milk cartons to develop a simple solar water heating system, a cheap home solar water that anyone could build.The environmentalist He devotes an excellent article to him telling his story:
… Seeing that in their small town of Tubarão there was no infrastructure to recycle containers and feeling unable to throw all these containers in the trash, Alano and his wife quickly found themselves with a room full of bottles of empty milk and cartons. […]
Using their ingenuity and experience with solar collectors, he and his wife built an alternative version using 100 used PET bottles and 100 milk cartons. The prototype worked flawlessly, while responsibly breathing new life into all that waste.
Since the invention of this solar water heater in 2002, Alano has continued to spread this idea in Brazil through conferences and workshops in neighborhood communities and schools. Local entities, the media and even electricity companies have collaborated in spreading this wonderful practice. The exact numbers are not known, although Alano mentions a few:
More than 7,000 people are already benefiting from these self-built (DIY) collectors in the state of Santa Catarina alone. There are already two cooperatives, one in Tubarão and the other in Florianópolis, the last of which has produced 437 collectors to be installed in town halls. In the State of Paraná, the number of collectors installed in 2008 was 6,000, thanks to workshops and brochures distributed to the population.
What’s most impressive is hearing how Alano describes himself:
I don’t consider myself an inventor, but a simple citizen who tries to find solutions to problems.
How to make a solar water heater with bottles
Let’s see what basic materials are needed:
- 2L plastic bottles (60)
- boxes (50)
- PVC pipe 100mm (70cm)
- 20mm (11.7m) PVC Hose
- PVC elbows 90 degrees and 20 mm (4)
- 20mm PVC T-Connectors (20)
- 20mm PVC caps (2)
- PVC glue
- matte black paint
- 1 roll
- self-fusing tape
- rubber hammer
- Mountain chain
- a wood or other material for the support
The 100 mm PVC pipe is used as a mold and the bottom of the bottles is cut. The 20 mm PVC pipe is cut into 10 x 20 x 1 m and 8.5 cm pieces and assembled with the T-connectors. long. And they are assembled.
The panels of the domestic solar water heater must be placed at least 30 cm below the tank and be located to the south, in the northern hemisphere, and to the north in the southern hemisphere, on a wall or roof.
To optimize heat absorption, the panels should be mounted at the angle of your latitude, plus 10°, this varies depending on the geographical area where it is installed.
PET bottles are replaced every 5 years or when they have been bleached from the outside and the carton is only repainted, with all of that described just give us a weekend for the assemble and have an aisle of these characteristics so particular
Let’s see the graphical example:
Download the full instructions in Portuguese
How to make a solar pool heater
Let’s look at our second example of making a homemade solar water heater for a small swimming pool. It’s something simple and not very expensive, so let’s see a step by step tutorial on how to do it.
The first thing is to understand what we are going to do. We will remove it with a by-pass so that part of the water from the filter circuit, once filtered, is directed to a secondary circuit where we will install our heater, as seen in the diagram below.
To build the homemade solar water heater, we will need the following:
- A T-type shunt.
- Two 90 degree elbows
- A pipe-sized shut-off valve.
- Approximately 60 meters of 20 mm (1/2 inch) black polyethylene pipe or similar.
- A plywood.
- Screws, fixings for the tube, black paint.
The process is first to make a frame with the 120cm x 120cm plywood, paint it black, mark the center and drill a hole the size of our pipe, in one of the corners we will do another hole of the same size.
Then we introduce the pipe through and start drawing circles as much as possible to then withdraw the pipe through the center of the frame we fix once we have all the pipes in place the inlet and the outlet we will place an elbow to do it is simpler.
We connect the lower part to the bypass that we previously placed with its tap after the chlorinator and finally we will put a section of pipe from the center of the heater to the pool.
As an improvement, we could place a glass or a polycarbonate on the frame to gain a few more degrees, the frame must be placed at an angle of 45 degrees or that corresponding to the geographical area in which we live.
A simple trick to calculate the angle of the sun is to use the same angle of the parallel where we live, i.e. if we live in the 37th parallel then we put it at 37 degrees from the ground.
The system will only heat the pool a few degrees warmer than usual. But due to the simplicity and simplicity of this homemade solar water heater, it is worth it.
On a sunny day with this system it is possible to raise the water temperature of this pool by about 14,000 liters from 18º to 22º.
Thanks to Rob for building and sharing this stuff with all of us and showing us that you can heat water using a coiled up black pipe in the sun: Rob A’s (im)personal blog
How to make a small portable portable solar water heater
Now let’s look at the third type of home solar water heater, in this case a small and portable one.
Heating water with the sun is relatively simple and good results are obtained when kept exposed to the sun for several hours.
The ideal temperature for shower water is 35 to 40 degrees Celsius, which can easily be achieved by exposing a black pipe filled with water to the sun. That’s why we are going to tell you step by step how to make a homemade portable solar water heater.
Materials to make our portable water heater with pipe
To make our homemade solar water heater that works perfectly with the heat we receive from the sun’s rays, we will only need:
- 25 meters of black hose with an inner diameter of 19 mm and an outer diameter of 25 mm.
- A 1/2 inch cut-off wrench with 1/2 inch male thread.
- A 19 mm pipe wrench.
- A roll of teflon.
- Half inch female plastic shower head.
- A board of 90 x 90 cm with a thickness of 1 mm.
- 15 meters of 0.5 mm galvanized flexible wire.
- A universal joint for any 19cm pipe faucet mouth.
- A strip of 4 x 4 cm 2.5 m long.
- A few pliers and a screwdriver.
- 2 plumber tap wrenches.
- Band saw and miter box.
- Clamps or flanges.
- A brush and carpenter’s glue.
- A 3mm auger or a drill with a 3mm bit.
- team of carpenters.
- Tape measure and pencil.
They may seem like a lot of materials, but most of them are the ones we usually already have in our workshop at home, at least those of us who are avid do-it-yourselfers and do it ourselves.
Assembling our portable home solar water heater step by step
First step. On the board, draw two lines joining the vertices of the square. From the center point of the board to the corners, make marks every 2.5 cm.
Finally, at each point of the lines, the 3 mm diameter drill or auger passes, leaving the last 5 or 6 marks undrilled.
Second step. Cut the four corners of the board 4 cm from the hole closest to the top.
Third step. Start rolling the rubber hose over the board, leaving a 12 inch free end. By passing the thread through the holes, you will sew the pipe.
Fourth step. On his back you install a fixing system. To do this, prepare a frame with four slats 60 cm long.
Screw another strip of 60 cm on the board, because this one is very thin. Secure the top and frame with a hinge. To fix the inclination of the device, you can attach the leg and the homemade solar heater, to its lower part, with a strong cord or a metal hook.
Fifth step. At the ends of the pipe from the homemade solar water heater, install two cut-off wrenches or fittings. The inner end of the pipe will be where the water will come in, and on the other end you can put a faucet on it because that’s where the water will come out.
Operation of the portable water heater
In the schematic section of the drawing you can see how the sun’s rays are absorbed by the black snail and heat the water inside. The circle (1) shows an enlarged detail of the operation.
There is also the possibility of making the radiator with a copper pipe painted black. In this case, the system is basically the same, except that copper retains heat longer.
In this video you can perfectly see how to make the portable solar water heater with a few variations, but with copper instead of a plastic pipe:
Do you know any ways to make a homemade solar water heater?
These are two ways that exist to make a homemade solar water heater. If you can think of another one, or a possible variant, either with recycled materials or accessible and sustainable materials, or how to build a device to heat water or food with solar energy, even if it is is different, share it with us in the comments.