Tileable 3D compound parabolic concentrator (CPC)

thingiverse

This design bears similarities to the trough CPC model, but with its three-dimensional shape created by rotating the profile around an axis, it produces a significantly higher concentration ratio. This enables more effective heating results. It features a collection angle of 45 degrees, which translates to a moderate concentration ratio of approximately 2. This configuration is intended for warming up a small glass jar. One can also use this design to cool down items efficiently. The infrared radiation emitted by the contents within the jar can be directed towards the most transparent part of the sky. As a result, there's effective radiative heat transfer with the colder atmosphere above, thereby facilitating cooling temperatures lower than that of its surroundings. The process is illustrated by the accompanying image, showing thermocouples set up to monitor temperature differences. At 85 degrees ambient, the jar inside reaches a stable temperature of 77 degrees, recorded on a warm summer evening. Preparation Requirements Before constructing this device, note that you will need to create accurate fillets for the inserts. While it's advisable to aim for a tight fit in your printed designs rather than relying solely on sufficient material availability, excessive errors can hinder optimal performance. In selecting reflective surfaces, I've chosen aluminized mylar due to its excellent reflective capabilities. Aluminum foil also serves as a suitable substitute in such applications. Tips and Variations For increased cooling efficiency, consider applying a white coat of paint to your glass jar. Under low sunlight conditions or at nighttime, it should be possible to achieve cooling temperatures lower than ambient air levels. Additionally, in regions where the autumn season offers freezing nights and above-freezing daytime temperatures, this setup can potentially facilitate ice production based on local humidity conditions.