Solar Water Heater Inexpensive to Make
Dear Jim: I want to become more green, and my children are all for it. From what I have read, using a solar water heater makes the most sense. I don’t have much money for one. How can we build a simple one ourselves? – Pat F.
Dear Pat: Solar water heating makes the most economic sense for almost every region of the country because hot water is used year- round. This is in contrast to solar space heating which is used for only about six months each year and its maximum output is needed when the daylight is shortest.
Since your budget is limited and your children want to help, building a simple batch-type solar water heater is your best option. It isn’t as effective as an elaborate active solar system, but it doesn’t cost thousands of dollars, either.
Depending on the scrap materials you can find, you should be able to build a batch system for less than $200, and the savings will pay back its cost in a couple of years.
The hot water heating energy savings you can expect to realize depend upon the specific design and your climate. During the summer, a 50-percent savings is reasonable as is a 25-percent savings during fall and spring. In many areas of the country, it is best to bypass the solar heater during winter to avoid freezing and possible damage to the heater or plumbing.
A batch solar water heater is used as a preheater for the incoming cold water before it reaches your standard water heater. If the water is warmer, it takes less gas or electricity to heat the water to the regular hot water temperature (120 degrees is best). On a hot sunny summer afternoon, the solar heater can warm water enough that the water heater stays off all day.
The most common design of batch solar water heater uses a water tank inside of an insulated box with a clear top. Special solar water heating tanks can be purchased, but first contact plumbers to find one or two old discarded water heaters that don’t leak. Strip off the sheet metal skin and insulation to expose the steel tank. It will already have the plumbing fittings.
The water heater tank should be painted flat black. Special solar paints, which are formulated to absorb more solar heat, are also available at a reasonable cost. Use an old glass storm door or buy a sheet of clear acrylic plastic for the top. For the greatest year- round solar gain, slope the clear top at an angle equal to your latitude angle.
Run the hot water outlet pipe from the tank through the back or side of the box and then down near the ground into your house to the water heater. Run another incoming cold water pipe from the water heater to the solar heater.
Insulate them very well. Install a crossover pipe and two valves to bypass the solar water heater during winter.
Dear Jim: I have a small electric space heater. It has a thermostat on it, but it is inaccurate. Is there any way to improve that thermostat or can I add another better thermostat to the space heater? – Sean C.
Dear Sean: Many of the small electric space heaters have thermostats with just a low-to-high indicator. One method is to try various settings to find the temperature you want and then mark that setting on the thermostat dial.
Another option is to install a line-voltage thermostat just for the wall outlet where you plug in the heater. These thermostats are often used for standard baseboard electric heating and they are very accurate.
Send inquiries to James Dulley, The Topeka Capital-Journal, 6906 Royalgreen Drive, Cincinnati, Ohio, 45244, or visit www.dulley.com.
(c) 2008 Topeka Capital Journal. Provided by ProQuest Information and Learning. All rights Reserved.