My submission is a design for a solar air heater utilizing 250ml cans and 3D printed components.
The idea behind my submission is a simple effective device that uses solar energy to heat air. The resulting heated air could be used for purposes such as heating shelters for people or animals or green houses. The heated air could be stored using various thermal storage apparatuses and be released during times when sunlight isn’t available.
A goal of my design was a functional design that is safe and easy to assemble, versatile and that would incorporate features that would highlight the possibilities that 3D printing opens up to part design compared to the limits that previous conventional manufacturing imposed on part generation. With 3D printing we can now design parts that have features in one part that using past technology would have required an assembly of several parts. We can also incorporate geometry that previously would have been very difficult or expensive to include. An additional goal was a design that would incorporate multiple 250ml cans with the reasoning that the more repurposed the less that end up in the landfills.
Regarding safety, my concern is that in order to repurpose the 250ml cans many designs would likely require some amount of cutting of the cans. Cutting these cans can be dangerous as cutting exposes very thin, razor sharp edges. My design requires only cutting the top out of the can from inside of the top seam which helps to keep the sharp edges from being exposed. I have also designed and printed a special cutter in order to facilitate the cutting in a safe manner. Photos of cutter included with submission and further description of cutter and cutting process included in an addendum.
To address the ease of assembly, I have designed the parts to snap fit together, requiring no tools.
To address the versatility this design can be configured in many different ways. Multiple individual assemblies can be fitted together into whatever configuration is desired. Included in the drawings that I have submitted is one example of a configuration that would be possible but there are many other configurations that are possible and imaginable.
As far as highlighting the 3D printing design possibilities available without the constraints of previous manufacturing methods, I believe that the part speaks for itself, I can’t imagine trying to manufacture the part that I titled “Manifold”, especially in one piece, using any previously known manufacturing methods.
Following are some explanations that I would like to add to the drawings that I have also uploaded with the pictures.
Drawing 1 of 4- This drawing shows an exploded view of the components. The 3D printed components are the Manifold, the Intake Cap, and the Exhaust Cap. I have shown two Manifolds but a single Manifold can be used or any number of Manifolds can be connected together in series as desired. Only one Intake Cap and one Exhaust Cap are required for however many Manifolds are connected in a series. The Manifolds are designed to snap fit securely together and the Intake and Exhaust Caps snap fit into the Manifolds. The 250ml cans shown have the tops cut out and they fit over the tube with the helical feature and then snap fit into the Manifold. The jars shown could be optional but they are intended to prevent thermal heat loss through the movement of air around the cans, sort of like when an automobile windows are closed rather than open on a sunny day. These jars are standard 16oz. Mason jars that are easily acquired and they simply screw onto the Manifolds which have the appropriate accepting thread. Depending on what is available in the region that this device is used it may be possible to find an appropriate jar that is repurposed for this application that would normally either be thrown away or recycled in another manner.
Drawing 2 of 4- This drawing shows the assembly of the two Manifolds and other components.
Drawing 3 of 4- This drawing is a diagram showing the air flow through this device. The air enters the Intake Cap and flows through the intake air duct and then up through a tube and out its end which is near the inside bottom of the 250ml can, the air then flows back down between the inside of the can and the outside of the same tube that it came up through. The tube has a helical feature that causes swirling of the air to help expose more air to the can side walls in order to conduct heat from the can more efficiently. The heated air then enters the exhaust duct through ports that connect the inside opening of the can to the exhaust duct and on out through the Exhaust Cap. The air exiting the Exhaust Cap would be ducted by whatever means necessary to reach the area where the heated air is needed. The intake air would also be ducted by whatever means necessary from an appropriate location. A thermostatically controlled fan would be used to push or pull the air through. I believe that a passive design may also be possible if the configuration was tilted exhaust side up so that the rising hot air would pull the cooler air through.
Drawing 4 of 4- This drawing shows one of many possible configurations of these components. In this example it is an array of 10 by 10 manifold assemblies that are contained in a structure that could be made of wood. I imagine that a structure such as this could be mounted on the roof of a building.
Also included with this submission are photos of the individual 3D printed parts and also of the assembly.
Thank you for considering my submission.