How to make a homemade solar heater

With just over $ 5, lots of recycled materials and 3 hours of labor, we can build our own solar water heater. It is still in the process of improvement but it promises a lot. Right now, it gives us the ability to heat small amounts of water to a decently warm temperature.

After a first attempt at a thermal solar panel, we were a little disappointed with the results. It took about 4 hours for the thing to start working, and the build was a bit expensive (over $ 50).

But we knew it could be done better and cheaper. The first mistake with the first prototype was purchasing all new materials, without using recycled materials, which made the product more expensive. With reusable resources extended to local landfills in our cities, we knew it could be done for less.

Another flaw of the first panel was the use of a plastic liner, which does not absorb heat, as well as other materials (like metal) that are more difficult to work with when you have to use heat. glue or tape to create an air bag to hold water.

We solved this problem by using a metal collector.

How to make a homemade solar heater

The last major flaw of our first panel is that it used plexiglass for the facade. It is difficult to work with because it cracks. We fixed this problem by using an old glass window.


Now on the new project. The first thing we did was collect all the components, most of them recycled.

Our local landfill has a freon removal program for refrigerators and dehumidifiers. There we found the perfect heat collector. The back of a refrigerator is basically a heat dispersal system, with a slight modification it can be used to collect large amounts of heat.

Make sure the freon or other refrigerant has been removed.

The wood for the structure is chosen from an old, unused sofa.

I found a glass panel and an old rubber mat which makes the perfect front and back.

The glass was a real find, and maybe the only panel piece to buy. Make sure your glass is large enough to fit in your collector and has enough space to secure it to the frame.

The doormat was huge so I had to cut it in half.

With the backing cut to size, it’s time to start building the frame.

As you can see, I kind of built the frame around the collector, leaving enough support to hold everything together.

The frame is made by building a similar frame at the back and using large wood screws through the front frame.

I added paper to the support. The reason is that contrary to what you might think, I don’t want the backup to heat up. You just want the collector to absorb the heat.

Light can pass through glass, but not heat.

I used duct tape on the inside to seal all the cracks, you can also use putty but I didn’t have any so use the cheaper option. It worked well and it keeps the blade in place.

Then we cut a few notches for the entrance and return to the collector.

Again, I use masking tape to seal the cracks.

Next, we attach the collector to the folder, using the mounting brackets provided in the refrigerator and duct tape.

As you can see, the simple duct tape is enough to keep it. However, I recommend using some type of backing, because after a few days in the sun the tape started to break down which allowed the glass to slip off. A few screws would fix this, but I’m cheap so just put new tape on.
Set your panel at an angle so that it captures the most sunlight.

Here’s the raw part, put one end of the hose in the bucket of cold water and make sure it’s at the bottom of the bucket, next to grab the return hose and start sucking. That’s right, unfortunately you have to prime the panel to get water in it. This can be done without having water in her mouth, but inevitably she sucked me a little too hard and ended up with a nasty sip of water. I would recommend a friend to do this part. 🙂

Set your bucket of cold water (fountain) higher than your bucket of lukewarm water (back) and the whole thing will siphon by gravity. Due to the design of this manifold (both ports return to the same location on the panel), it is not heat siphoned. To make this happen, I would have to cut the long return tube and pull it out at the top of the panel.

A word of warning, this sign works very well. We tested it on a very sunny day and within seconds the water coming out of the panel was hot enough to scald. I burned my fingers. This very hot water is only formed when the water inside the panel is allowed to stand for a minute without moving. If the water is moving (made for the gravity siphon), the water coming out of the return tube is about 110 degrees, and as long as it is hot it will not burn you.

The water does not pass through the panel very quickly (as the pipes are very small), but this is quite a good thing as it allows the water to get very hot as it travels through the collector. However, it does take a while to heat a 5 gallon bucket of water, I finished building an insulated return bucket that was all black and sealed on top except for the port where the tube goes into it. water. This keeps the hot water returned hot enough to be useful.

I left this type of run for a few hours on a hot, sunny day and heated a five gallon bucket of cold water (measured at 70 degrees F) to over 110 degrees F. The temperature that day- there was about 76 degrees If the water was left to sit on the panel for several minutes and then expelled (by blowing into one of the pipes), the water was measured at 170 degrees F. In the end, we are much more satisfied with the performance (and the cost). of this panel. It works much better than the previous one.

Our next modifications to this design will be to modify the return port so that it is heat siphoned, this way the return pipe can be fed into the bucket of the fountain and water will continuously flow through the panel becoming more and more hotter. . We also discussed adding mirrors to the panel to concentrate more heat. Our goal is to boil the water. This whole project will cost less than five dollars because I already had the screws and duct tape. The only thing I bought was the air hose, which cost $ 3.76.

Full instructions:

Enjoy free hot water!