Capstone Project: Solar Water Heater Andrew Black, Jack Nordloh and Jesse Weber

The Design Thinking Process Understand Explore Define Ideate Prototype Refine Solution

Understand As renewable and green energy become increasingly popular, so do their home and DIY applications. Most popular among these are solar panels, which, mounted on roofs, can reduce electricity bills, and surplus energy can even be sold back into the grid for a profit.

Explore Although investing in solar panel is quite expensive at the moment, a similar installation can also reduce bills and conserve energy. Solar water heating is simpler to construct, and requires less sophisticated materials.

Define The goal of our project is to construct a simple mounted reservoir of water (using transparent materials) such that the water can be safely heated to warmer temperatures (~100* Fahrenheit). This project can be further expanded by comparing the heat of processed water at a given time to the illumination of the sun at that time. The tank assembly should be sturdy, easy to access, and aesthetically pleasing.

Ideate

Ideate (Cont.) This was a base idea on how the reservoirs and coil should be positioned.

Prototype Our first prototype involved a cardboard box with the coil running from top to bottom. The open side faced south in order for it to receive more direct sunlight. We decided the best way to heat the water was to do it in batches. This way the water would basically just sit in copper and heat up, then we would release that batch and heat a new batch after that.

Refine We refined our original prototype by wrapping the box in saran wrap in order to retain heat in the box and rely more on the greenhouse effect. The saran wrap would let the sunlight get in, but would block the thermal radiation from escaping, and instead cause it to radiate in all directions, thus helping to heat the inside.

Solution We then finalized the box as shown to the side. Our final additions include spray painting the inside and outside of the box black, along with the coil. We also wrapped it in a way that seemed more effective in trapping in heat and allowing less gaps.

Solution (Cont.)

Problems and Revisions Several issues with the design were very obvious after the experiment concluded -Leakage from the top reservoir: This should not have affected temperature, but would be very undesirable in a commercial version. This could be addressed by increased and more precise application of sealant around the pipe

Problems and Revisions (cont.) -Depth of container: We hoped to increase the heat of the container by increasing its surface area; however, in doing so, we stuck with a square base, and consequently had too much volume to effectively heat. Using a thinner rectangular shape would retain surface area, while staying small to utilize the greenhouse effect well.

Problems and Revisions (Cont.) -Holes in plastic wrap: Any vents like these would allow massive heat loss. The most obvious solution here is to select a heavier-duty material; one that rips and tears less.