Build a Solar Water Heater Easy
Tips and Examples

Solar water heaterSolar water heater

Tips and ideas on how to build a solar water heater. What you should know for a simple, almost free and an 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.

For this homemade DIY project, you can use already available materials you have, which is a cheaper option or to buy a kit. The advantages of solar water kits are the proven results and detailed instructions on how to build, which is not a case with DIY or homemade equipment.

In this article:

Build a solar water heater - Tips

To build a homemade solar water heater successfully, you need proper planning, be able to visualize and design 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 for hot water transfer.

This idea can be improved by making it more efficient, setting them in the insulated box with a glass or fiberglass cover and with the small additions.

Tips for the more advanced unit:

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 season.

The sun-powered water heater can be installed horizontally, vertically or diagonally, depends 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 an easier assembly, you can buy a mounting hardware kit.

Build a solar water heater - Simple and almost free homemade batch system 

Step 1

The first step when you build a sun-powered heater 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.

Step 2

Build the walls or sides of the heater box, using plywood, or if you have any other material handy. Inside of the box should be covered with the materials like fiberglass insulation, Styrofoam or aluminum.

Step 3

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 will you 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. 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.

Step 4

Insulate the pipes, to reduce energy and heat loss, so your built solar heater can be more energy efficient.

Step 5

The final step in your DIY, build a solar water heater box, is to cover the box. There are many effective materials available for glazing, like acrylic, polycarbonate, fiberglass, glass, 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 a tempered glass as a cover. Talk to the local store to see what sizes they can provide, and based on that design your solar heater box. If you order a custom made, it can cost you more.

Step 6

In this step, you should work on details that will determine the efficiency of the system.

If you are using 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.

Videos how to build a solar hot water heater

How to build solar water heater by using the copper pipes... 8 videos total.

How to install a cheap and cost-effective SWH using a black hose

How to build a batch system

Solar panels and thermosyphon system

The above described DIY solar hot water system is called an integrated solar heating system, or simply the batch, where the collector and storage tank are combined into one unit. These systems are useful in the southern, warmer areas, while in northern climates where it can be very cold, 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 so it can attract even more sun’s heat, together with the panels.

Solar panels are made of the black painted copper pipes, installed in the insulated collector box and with a cover-glazing, made from the 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 in achieving their goals in using the renewable energy for water heating.

More examples and plans
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