Build Your own Passive Solar Water Heater
(Page 6 of 7)
October/November 2007
By David A. Bainbridge
One of the best ways to get started is with a group of friends. Build a series of water heaters together and make it a fun project, sharing labor and expertise. Someone will have the plumbing tools and skills; someone else, the carpentry skills and tools. The combined good sense of the group will get the job done quickly and safely.
RELATED CONTENT
How Hot Is HOT? February/March 2004
The Other Chile Peppers
Where does the h...
Want to know how to build your own photovoltaic system, how to construct a solar water pump, or eve...
It’s not every day that you get a chance to tour a green home. Well, here’s your opportunity! Every...
A string of new solar manufacturing plants are scheduled to open within the next few years....
Your woodstove can heat more than your home. This hot water heating system uses extra heat to produ...
If you’re not a do-it-yourselfer, there are numerous effective commercial solar hot water systems available for virtually any location in the world (for more information, click here.) In colder areas, a thermosiphon system is often a good choice. Freeze protection can involve liquid antifreeze with heat exchangers, drain-back or other systems to avoid freezing damage. Many products now use evacuated-tube collectors to heat the water, which then rises into a well-insulated storage tank.
Of course, you don’t have to take my word for it. Look around, read around, shop around, and — most important — build for yourself. I think you’ll come to the same conclusion I did years ago that integral passive solar water heaters provide the most economical, efficient, down-to-earth method of water warming under the sun.
Modest Beginnings, Hot Results
The principles used in modern batch heaters are the same as those first applied to solar water heating more than 100 years ago. Robber’s Roost, Butch Cassidy’s 1880s hideout in Utah, reportedly still includes the remains of a passive solar water heater: a large black can filled with water and placed in the sun. The first commercial solar water heater, patented in 1891 by Clarence Kemp, used four cylindrical water tanks housed in a pine box covered with single-pane glass. By 1900, more than 1,600 of these units were in use in the United States. In 1898, Frank Walker, of Pasadena, Calif., applied for a patent on an improved design. Walker’s model was recessed into the roof, instead of exposed on top of the roof like Kemp’s heaters. The Walker unit also incorporated connections to a woodstove with a water-heating tank for backup heating, the direct forerunner of today’s most common batch heater application: a solar preheater feeding into a standard water heater in the house.
As successful as these early heaters were, they gradually disappeared as oil, electricity and natural gas became available. These new, seemingly cheap energy sources brought high costs in environmental damage, human health, global warming and habitat damage — but these costs were, and still are, ignored.
Fortunately, these new energy developments didn’t bring solar water-heating research to a total standstill. At the University of California, Davis, in 1936, F. A. Brooks tested several heater designs and demonstrated that tank-type solar heaters could produce water temperatures in excess of 120 degrees. He also discovered that upright tanks placed on an incline delivered hotter water than horizontal units. Brooks concluded that batch heaters could produce hot water at a cost consistently below that of flat-plate solar systems.
Page:
<< Previous 1 |
2 |
3 |
4 |
5 | 6 |
7 |
Next >>
