Heating costs continue to rise and while energy conservation through lowering the thermostat combined with insulating and sealing your home helps keeps those costs down there are other ways to help reduce your heating costs. A logical place to look for a free heat source is the sun. Many of us already take advantage of solar energy during the winter months by opening window coverings on sunny days to help warm rooms and closing them on cloudy days and at night to keep the heat in the room. Using a few recycled items we can take advantage of those sunny windows to boost that heat output by using simple homemade solar heaters. Over the next month or so, I will be making a few posts on homemade solar heaters.
These solar heaters are not meant to be your sole source of heat. They are meant to supplement your existing heat. The more you use the more savings you will see on your heating costs. Keep in mind that if you live in an area that has a fair number of grey days with little sunshine, the solar heaters will not produce any heat. They also will not produce any heat in north facing windows.
I found the following video that shows how to make a rudimentary solar heater using recycled pop bottles and beer cans. Aesthetically this solar heater might appeal to you but it is a very inexpensive way to get a good idea of the possibilities of using a solar heater. Surprisingly this solar heater will work quite nicely in a sunny window. It would be a good project for parents or teachers to introduce solar energy to children.
This homemade solar heater follows the basic principles of all solar heaters. There is an air flow that goes through the collector (tin can) that is heated then released. The glazing (pop bottle) intensifies the heating effect. The air flow moves from the bottom of the bottle (cool air) to the top of the bottle (hot air) due to physics. Hot air is not as dense as cool air so it rises. This simple solar heater takes advantage of this principle.
Despite its looks this heater will work and can be modified to fit the size of your window. The best part is you are using mainly recycled materials so the cost is minimal. The kind of pop bottle really doesn't matter as long as it is a clear 2L size. Beer cans are taken back to the Beer Store for a cash deposit back so I would recommend using pop cans and adjusting the size of each solar unit to fit the can. The tape will make a somewhat adequate seal. What I would suggest is to run a bead of clear silicon seal around the bottom portion of the unit before pushing it into the upper portion then running a smooth bead of silicone on the resulting outside seam. Also hand painting is rather tedious. A spray bomb of flat black paint will have the cans quickly coated in a lot less time than brushing on the paint. When it comes to mounting this particular solar heater you will want it a few inches from the window sill simply for air flow but I don't think hanging the heater is the best way to go. Eventually the glue will give way causing the individual units to fall as well. What I would advise is using wood dowels. Attaching two dowels within the window frame on which each solar unit could sit then another dowel spanning from distance between the window frame would create the perfect spot to simply set as many units as would fit across the span of the window. The air flow would not be restricted either. So this simple design has a lot of potential. It would be an ideal way to add a bit of free heat to basement windows!