Use Storm Windows to Make Solar Collectors

To keep the cold out and bring the warm in, assemble low cost solar panels with storm window frames.


| January/February 1984



Rear Surface of Solar Collector

Foil-faced insulation board makes up the panel's rear surface.


MOTHER EARTH NEWS STAFF

Over the years, MOTHER EARTH NEWS staff tinkerers have come up with a variety of solar devices, most of which have been designed for those who want to give the sun a try without incurring a lot of expense. But then—after all of our past efforts—whenever we tried to come up with some original solar projects, we were stumped for ideas. (Was there really nothing more new under the sun?)

But all of a sudden, our researchers hit upon the idea of using salvaged storm windows and aluminum frames as the basis of low-cost, weather-resistant, simple-to-assemble solar collectors—and a promising, economical approach to backyard solar technology was born. After all, the triple-trackers seem almost custom-suited to the application, since they're [1] preformed in perfect shallow "collector shape," [2] made of lightweight, durable, heat-resistant material (a stagnant wooden collector can, over time, start to smolder), [3] already equipped with precut, tight-fitting glass, and [4] commercially fabricated, giving them a finished "marketplace" appearance.

On top of all this, secondhand frames—at least the ones appropriate for this project—can often be obtained for a few bucks apiece. Many people are upgrading their windows' weatherizers with new or color-coordinated storm fixtures, meaning that plenty of old-but-sound frames are finding their way into the trash or to salvage houses. Even sashes that are missing a pane can be recycled. In fact, a shrewd buyer could probably pick up such "worthless" castoffs for next to nothing and replace the damaged glass with sheets cannibalized from other junk windows!

However you acquire the materials for storm window solar panels, all that does matter is that you locate two frames of the same size and come up with enough glazing to seal one of them tightly. Remember, though, that it's to your advantage to search for large units (they don't have to fit your own home's windows), since they'll naturally offer more absorber surface area.

Once you've latched on to one or more pairs of equal-sized storm sashes, you'll need only to come up with a few more items—which we've specified in our list of materials—to make your solar project a success. The back of the collector and its absorber is a single sheet of 1" foil-faced rigid foam insulation board. The inlet and outlet ducts consist of 4" holes cut in that board at opposite ends. A thermostatically controlled box fan draws air through the collector and exhausts it into the room. And a couple of clothes-dryer fittings, some flexible hose and a channel made from sections of insulation board complete the connection between the air ducts in the collector and those in the living area.

To attach your solar storm window as effortlessly as possible, you'll probably want to use an installation similar to the one shown in our photographs. The collector mount is an adjustable board assembly designed to fit in the tracks of any partially open double-hung window. Once the sash is closed tightly against this insert (foam stripping at the joint will assure a weathertight seal), it's sturdy enough to support the weight of the solar panel on the two brackets extending from its outside face. To help give the aluminum collector walls some structural support, a tubular framework is fastened to the edges of the panel "sandwich," and—to hold the unit at an optimal angle to the sun—a pair of rubber-tipped legs stretch between the frame and the house's exterior.

carol langston
12/21/2012 5:33:09 PM

How do you print the Materials' List from the Image Gallery where it is readable and not so small?


kevin key
9/12/2008 11:22:00 AM

Any reason why a used sliding glass patio door would not work? The best window for this sort of collector on our home would be three side by side windows in the central room of our home, which is even wider than a patio door set on it's side. Enough space between the doors if laid on top of one another or would I need to build a spacer?






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