If you want to heat your home but are concerned about the environmental cost of doing so with fossil fuel based solutions, you can make your own solar heating system for your home. This alternative will not only impact the environment, but it will be economical because with around $ 350 you can buy whatever you need for its design. Here’s how to make this radiator from a retired aeronautical engineer.
Solar air heater.
The idea is to create a system solar panel air heater with thermosyphon. After analyzing the different alternatives available, this engineer opted for this solution because of its good results and the simplicity of the design, among others. In fact, on a sunny day, this heater can produce the same heat you get using $ 3 of natural gas or $ 2 of propane.
The collector is essentially made up of polycarbonate panels that admit sunlight which, in turn, is captured by an absorption system. Around it, the air heats up and rises, creating a current of convection.
The different vents of this system allow the air to circulate, which enters the cold from the lower part, to be heated and raised to the upper vents to, immediately after, return inside, where the flow continues for that sunlight hits the heater.
Solar air heating for the facade.
You can find them at any home improvement store. They are as follows:
- 2”x6 ” wooden board.
- 2”x8 ” wooden board.
- Wood 1”x1 ”.
- Corrugated polycarbonate sheets.
- Foam adhesive strips.
- Screw with washer.
- Paint, sealer and lag screws.
- Lightweight plastic sheet.
Determine the size needed.
The maximum, the higher the better, works in the case of this collector, especially considering the heat loss of many buildings due to infiltration and insufficient insulation. Building a collector that takes up an entire south wall of the house will not have a high cost in labor or money. The use of a solid wall for this system, however, is not the most suitable for temperate climates, buildings with good insulation and those longer on the east-west axis than on the north-south axis.
Manufacture of the collector.
The frame of the collector is made of wood of standard dimensions and has vertical pieces and crossbars at the bottom and top.
In this example, six 2×6 vertical planks were used which divide the manifold into 5 areas approximately 30 centimeters wide. The lower crossbar is 2 × 6, while the measures of the upper bar are 2 × 8.
In order to secure the components of this frame to the wall, internally driven lag bolts were used.
After the structure is well fixed, the corrugated polycarbonate sheets are added to the collector. Typically these have an ultraviolet resistant layer on the outside which extends the useful life of the material.
In this case, ten sheets were used, each of them 66 centimeters wide and about 2.5 meters high. Each pair of panels are stacked and assembled with a 1 × 1 wood strip to fit each of the 12 inch areas of the frame.
A black metal screen will allow absorption of the system. This will need to be installed on the vertical planks and through the top and bottom of each of the manifold areas.
After performing several functional tests with different screen layers, it was decided for this project to use the double layer.
To equip the ventilation system, it is sufficient to drill holes at the top and bottom, along the covering of the system. With lightweight plastic flaps, you can prevent reverse flow through the top vents at night.
A note for the summer. While the vertical orientation of the panels and their angle generally minimizes the risk of overheating, blocking the ventilation openings at the top will prevent the manifold from producing heat. To do this, you will simply need to staple a piece of cardboard over each vent, although you can also choose to install ventilation doors. In the spring and fall, you can open and close the vents according to your heat needs.
Some tips to facilitate construction.
The first thing to do is measure the south facing wall of your home to determine your collector’s design. Pay close attention to the height you have and the space for the lag bolts.
You will then need to design the vents. At this point, it is important to keep in mind that you need to leave enough space to place the vertical planks and secure them inside the building. Also, remember to mark where you will place the vents on the outside and inside of the wall, to make sure they don’t interfere with the electrical wiring. When you rule out this possibility, make the holes and remember that you will have to bevel the upper end so that it has an inclination of about 10 degrees, so that it will drain water in case of rain.
Then cut the verticals by tilting their tops to match the previous slope. Line up the pieces and cut out the wooden notches to secure the polycarbonate cover.
The next step will be to paint everything except the coating that will remain behind the manifold, although the dark colored paint will help improve the efficiency of the system.
After the paint has dried, mount the vertical siding and secure it from the inside with washers. Make sure everything is straight and level to save yourself more work later.
Then you will need to fix the lower and upper rails. If you live in a rainy area, you can incorporate a sheet of metal on the top that prevents water ingress. Once you have the crossbars in place, be sure to seal the entire perimeter with silicone. Remember to fold the edges of the screen to fit each area of the system.
To make your panels, don’t forget to assemble the corrugated sheets and fix them with silicone. Reinforce the junction areas of the plates by screwing a small strip of wood (2.5 centimeters) into each of them.
To assemble the panels, install the adhesive foam strips to match the contours of the corrugated panels. Apply a line of adhesive to the first vertical group to mount the first area of your system. To secure the panel to the frame, use screws with washers. Repeat with the rest of the sections. You will need to overlap each of the areas you are installing with the previous one, so apply sealant to the joint point.
For the top vent valves you can use garbage bags but, first, add net in each vent to prevent the valves from being sucked in. Once you’ve done that, staple the valves just above the vent opening.
Improve system performance.
If you want to improve the performance of the system, you can apply slight modifications to the described process. Among them, for example, the replacement of polycarbonate glass with a single corrugated sheet. This can reduce heat loss through the glass.
Another modification that can give good results is to alternate the collector panels with the windows. With this, the system would admit more sunlight, which would lead to direct heat gains, but avoid the losses and overheating that can occur in walls made entirely of windows.
After about three days of work, you will have completed the homemade solar water heater. If you want to enjoy it more, don’t rule out improvements in your home’s insulation so that the temperature is maintained for longer. In the meantime, with this system, you can heat your home at no additional cost to your bills or to the environment. In fact, the proponent of this design estimates that equipping a home with this heater can lead to a greenhouse gas reduction of around 800 kilograms per year.
Original project in Mother Earth.