Cut utility bills with DIY solar water heater

Q: Based on our water bills, my family uses lots of water and much of it is probably hot water. Is there a simple solar hot water system design that I could build myself?

A: Heating water can account for a significant portion of your monthly utility bills. It can be 20% for the typical family of four. Gas water heaters are less expensive to operate than an electric one, but they also cost more initially to install.

Before you consider using solar or any other efficient water heating methods, install low-flow shower heads with shut-off tickle (lathering) valves. Also talk with your family about taking shorter showers. This not only reduces water heating costs, but it also conserves our fresh water supply.

Unless you are an accomplished craftsman who also understands plumbing, I suggest you make a simple batch solar water heater. This is called a passive system because the water moves through it due to the incoming line pressure or just temperature differences, yet it can be quite efficient and effective.

Trying to build an active system, with collectors on the roof, plumbing and control systems, and storage tanks is beyond the skill level of most homeowners. I am a design engineer and I don't think I could build a system from scratch for my own home.

A batch solar system is used as a preheater for your existing water heater. The incoming cold water flows through the solar preheater before going to your water heater. Every degree the water is warmed in the preheater reduces the amount of electricity or gas used by the water heater.

The simplest batch solar system is called a breadbox design. It utilizes a horizontal metal water tank inside of a box with a clear top. The sun shines in through the clear top to heat the water. Another slightly more efficient option uses a tall box tilted at an angle to face the sun. This allows the warmer water to be drawn first from the top of the tank.

You can buy a stainless steel water tank especially designed for this application with the inlet and outlet water fittings. If you can find an old water heater which is not leaky, strip off the metal skin and insulation to use the inner tank. Paint it flat black to absorb more of the sun's heat.

It does help to insulate the solid sides and bottom of the box especially if you plan to use it most of the year. Very heavy insulation is not needed because the tank will not get extremely warm, especially if you are using hot water throughout the day. One-inch-thick foil-faced rigid foam sheets should be fine. Attach them inside the box so they reflect the sun's heat to the tank.

Install water valves and plumbing so the solar tank can be drained and bypassed during cold weather. Install heavy insulation around any exposed pipes and bury as much as possible underground.

The following companies offer solar kits and components: Alternative Energy Store, (877) 878-4060,; Build It Solar,; and Solar Direct, (941) 236-5949,

Q: I installed a garage door two years ago. It works during summer, but sometimes will not close other times. It comes down one foot from the floor and then goes back up. What it causing this?

A: It sounds as if your garage door opener safety switch may be improperly adjusted. It is designed to reverse a closing garage door in case a child or some other object is blocking it.

During summer's heat, it moves freely enough to close. During cooler weather, something is binding or stiffer lubricant is causing just enough resistance to make it think something is under the door. Have a professional serviceman check the safety switch adjustment. Don't try to adjust it yourself.

• Send questions to James Dulley, Daily Herald, 6906 Royalgreen Drive, Cincinnati, OH 45244 or visit

© 2024 James Dulley

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