Tips and ideas on how to build a solar water heater (SWH). What you should know for a simple, almost free, and exciting homemade solar DIY project.
Building a solar water heater can also be expensive, unsuccessful, and very time-consuming, and that is why it is essential to follow the expert and manufacturer's instructions.
You can use materials you already have for this homemade DIY project, which is a cheaper option. You can also buy a kit.
The advantages of solar water kits are the proven results and detailed instructions on how to build, which is not the case with DIY or homemade equipment.
To build a homemade solar water heater successfully, you need proper planning, be able to visualize and design a solar heating system, have a basic understanding of carpentry, plumbing, welding, or soldering, have the necessary tools, and help, and be willing to learn.
How to build a simple solar water heater?
The simplest heaters are probably those that utilize discarded drums or barrels painted with flat black paint. I had seen many of these when I was visiting Greece; homemade solar water heaters using drums and installed on the flat roof, using gravity to transfer hot water from the tank to faucets.
This idea can be improved by making it more efficient, setting them in the insulated box with a glass or fiberglass cover and small additions.
Tips for the advanced units:
Build a solar water heater with a movable base, so it can change the angle (rotate) and have better sun exposure during the day or a season.
The sun-powered water heater can be installed horizontally, vertically, or diagonally, depending on your preference, location, design, and viability.
Build a solar water heater where it is easiest for you to make and install, like a garage or backyard. The best is to build it in sections for easy transfer and assembling. Of course, the simplest installation is on the ground level. For easier assembly, you can buy a mounting hardware kit.
When building a sun-powered heater, the first step is to design and make a wooden frame for the solar tank-solar collector. A 2x4 inch wood will do the job. The future box should be designed so you can apply a standard size of the insulation, cover, and other elements. You have to pay attention and build good support for the storage tank. One side has to be inclined so that glazing can have better sun exposure.
Build the walls or sides of the heater box using plywood or if you have any other material handy. The inside of the box should be covered with the materials like fiberglass insulation, Styrofoam, or aluminum.
Before you build a heater box, plan and design where the plumbing will be installed; the opening for incoming water and exiting pipes. Keep in mind how to connect it to the heating system and house plumbing.
Plumbing fittings and pipes should be installed at the bottom of the tank for water coming from the house, and another set on the top of the sun-powered water heater in the backup unit, for example.
During and after building a heater, always check for leaks. When filling the heating system with water, make sure to remove all the air from the tank. A bleed valve and temperature relief valve should be installed in your heater as well. The drain pipes have to run consistently downhill for easy drainage.
Insulate the pipes to reduce energy and heat loss, so your built solar heater can be more energy efficient.
The final step in your DIY, build a solar water heater box, is to cover the box. Many effective materials are available for glazing, like acrylic, polycarbonate, fiberglass, glass, or tempered glass. The idea is to increase the sun's heat through the cover and reduce the heat loss at the same time.
Because of its great characteristics, we recommend using tempered glass as a cover. Talk to the local store to see what sizes they can provide so that you can design a solar heater box accurately. If you order a custom-made glass, it can cost you more.
In this step, you should work on details that will determine the efficiency of the system.
If you use an old electric heater, strip off the outer enclosure and insulation, get rid of the old pipe fittings, and check the inside for sediments. Clean the tank if necessary.
Paint the tank in flat black to increase the heat absorption and install the pipe fittings, drain, and pressure release valve.
Seal all the exposed surfaces, run silicon along joints and connections, install reflectors to concentrate sun lights, include insulation or shutter at the top as a heat loss protection, and your homemade solar hot water heater is ready.
The above described DIY solar hot water system is called an integrated solar heating system, or simply the batch system, where the collector and storage tank are combined into one unit. These systems are useful in the southern, warmer areas, while in northern cold climates, these are much less efficient and not recommended, as the water inside the tank can freeze.
You can also build a heater where solar panels or collectors are separated from the storage tank. They are usually called the thermosyphon flat plate systems.
Either way, you go, you are using free energy, where the fluid located in the solar collectors is heated by solar energy and transferred to the tank.
The solar water heating system with panels can be installed on the roof or in the backyard, or wherever it is viable, and where the site has excellent sun exposure.
The storage tank can be used from the old electric heater and modified to accommodate a new design. If it is located outside, paint it in black to attract even more sun's heat, together with the panels.
Solar panels are made of black painted copper pipes, installed in the insulated collector box and cover-glazing, made from clear plastic or window glass.
Again, it is important to orient the glazing almost perpendicular to the sunlight. As the water becomes warmer, it rises to the top of the panel and from there to the storage tank, using pipes.
Use the reflective material for the inside of the box and paint the copper pipes in black. Insulate the box well. More about passive solar water heaters here.
If you have other ideas on how to build solar water heater, please click on this link and submit your ideas, designs, or help others achieve their goals in using renewable energy for water heating.