How to Build a Solar Water Heater

There are plenty of reasons solar energy is gaining popularity. One of the main reasons is the savings associated with using solar-powered appliances. As such, the demand for such appliances is sky rocketing. If you’re looking for cost-savings, continue reading.

While there are plenty of options for solar-powered appliances available on the market, some people prefer to build things on their own. The reasons for doing so are a high-degree of customizability and the desire to create something on their own.

Luckily, guides such as this one allow people to take advantage of the sun and build their own solar-powered devices. A water heater is common home appliance used to provide hot water for the entire home. Those who feel like the water bill is too high will be glad to hear that there is a solar-powered option for this too.

How to Build a Solar Water Heater

In this guide, we’ll show you how to build a solar water heater. As a result, you can reduce your burden on the planet, and enjoy great savings on your energy bill.

What You’ll Need

There are several designs that you can choose from when trying to build a solar water heater. The design can be one that you’ve drafted yourself, or one you’ve seen online. As a result of all the variables, we’ll focus on items that you’ll need generally.

Each design will have more specific items that you’ll need. To build your own solar water heater you will require the following items:

  • A blueprint, design, or layout – this will be a plan for the entire project and detail the specifications of all the items involved
  • A Tank – you can procure a used one from an old electric heater provided it’s in usable condition
  • Black Paint – to prevent algae formation inside the water tank
  • Box made of Plywood – This will be used to make the collector box
  • Hinged lid – this is to prevent heat loss at night
  • Material for insulation – to prevent heat loss, and promote heat retention
  • Mount – for placing the panels
  • Pipes and fixtures
  • Glass sheets

1. Calculations

Before you begin learning how to build a solar water heater, some calculations will be required. You will have to determine the size of the tank by adding each person’s daily hot water needs. This in turn will tell you what kind of pipes to use. To heat the total amount of water, you’ll need to know how much solar energy your system must capture in a day. There will be an optimal angle and height for the system to do so, calculate these.

2. Choose Location

The first thing to do is to choose an appropriate location for the placement of your tank. The ideal location will be where the tank will receive plenty of sunlight in the daytime. The solar collector should also be placed at such a place, facing in the direction where it will receive sunlight for the maximum amount of time.

You should try to keep the solar heater as close as possible to the backup heater. However, you should not do so at the expense of a good location. The close placement is meant to reduce the piping required.

Once the location is set, you decide where to place the tank. Remember, the tank will be quite heavy when full, so avoid placing it on the roof. Placing it on a platform beside the house is the go to move for most people. If you make sufficient preparations, it can be placed on the roof.

3. Collector Box and Tank

The next step requires you to build the collector box. Use the plywood box, glue insulation into it and then stick reflective foam on top of it. The tank can be constructed, but it’s better to just purchase one or utilize a used one.

When dealing with these items make sure that they are as efficient as they can be. A used tank might have a rusted or damaged heating core (anode). Inspect this carefully and replace if necessary. You may even wish to get a new tank, as these come with all the necessary adjustments by default.

4. Heat Retention

When the system is not under sun exposure, we still want it to retain some heat. At night it can get pretty cool and a lot of systems lose heat. You want to ensure that you get appropriate glazing for the system to minimize heat loss during the night.

For most DIY projects, glass glazing is fine. However, if your region sees a lot hail then it might not be such a good idea. In such cases you can go for a more sturdy material like twin-wall polycarbonate.

5. Connection to Backup System

You should not rely solely on your solar water heater. In winters, the backup system should be more appropriate. Connections should be built with this in mind. The supply should be able to run directly to the house from both the solar water heater and the normal one.

This will allow selective use of the solar heater, when it can actually be useful. When it cannot benefit you, such as in winters, it should be shut down. At such times, the conventional water heater should be just fine.

Our Final Thoughts

Remember that there is more than a single way when asking how to build a solar water heater. Each design offers its own advantages and presents some disadvantages. As a result, we’ve tried to offer general principles for construction in this guide.

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