Solar Hot Water

Solar hot water heaters use the heat from the sun to heat water. A solar hot water system is composed of a solar collector, a water tank, and connecting pipes. With the exception of batch heaters/ICS units, solar hot water systems work by cycling water from a storage tank to the collector, which heats the water.

Why Heat Your Water with the Sun?

Solar hot water is a good idea for a variety of reasons, including:

What are the Types of Solar Water Heaters?

If you are looking to install solar hot water, you have three main choices in solar hot water collection systems: flat plate collector, integral collector storage, and evacuated tubes. Which system is right for you depends on where you live, when you use hot water, and the strength of your roof, so choosing the right system can get complicated. Before buying any system, you should try to get a professional opinion. However, here are some steps you can follow to get a general idea of where to start.

Three Main Types of Collectors

How Do I know What to Buy?

To buy a solar hot water system, you need to know two things:

1. How much water you use.

2. How much water the solar hot water system will provide.

1. How much water do I use?

Figuring out how much water you use is fairly straightforward. First, find out the following information:

How can I find this information?

Once you have these numbers, use them to figure out how much water you use in an average day. Keep in mind that some of the water used by your showers, dishwasher, and washing machine is cold water, so this number is likely to be an overestimate of the amount of hot water you use and you should take that into account when performing these calculations. A spreadsheet to help you perform these calculations is coming soon.

Now you know how much hot water your solar hot water heating system will need to supply!

2. How much water will my solar hot water heating system provide?

To figure the energy supplied by a solar hot water heating system, follow these steps:

Now you?e done! You have all the information you need to size a solar hot water heating system for your building. Just choose the collector that is most efficient at the time of day you need your hot water, and size it to supply as much of your hot water demand as you can while still being cost-effective. There are still some details to work out for example, do you want a direct or an indirect system? but these details are better for the supplier to help you with because the supplier has experience working in your climate.

How Much Will It Cost? How Much Will It Save Me?

On average, solar hot water reduces the cost of your water heating bill by 50% - 80% (3). Use the spreadsheet that you will soon be able to download from this page to do more specific analysis on the solar hot water heater that you are considering

Other Terms You Might Hear Related To Solar Hot Water:

Methods of Circulation:

Methods of Heating:

Author: Lauren Leonard

Contributors: Nick E

References: (1) Energy Star, (2) Energy Star, About Housekeeping,(3) US Department of Energy, Energy Efficiency and Renewable Energy

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