Solar- Thermal Water Heating

Hello all, I’m JJ Galvin, the student team leader of the rEvolve house. Last summer, a small team of students worked on defining many aspects of the house so that we would be able to make progress during the school year. One of my favorite projects was designing a solar-thermal water heater. The idea behind this came from the large constraint on energy use in the house and how much energy a standard water heater uses. We first decided to add the water heating system to the existing solar panel array as an integrated hand rail. This is another form of dual-purpose use that is integral to tiny house living.

The next step was to design a smaller model that would tell us what kind of results to expect from our system functioning in the house. We figured out which components would be necessary and drew out a design. After checking the calculations with a professor, we bought parts and assembled the system in just a day. We then spent about a week testing different methods of running the pump in the system. We measured the heat at different parts of the system over time so we could track how long it would take to heat the water to an appropriate temperature. In the end, we were able to heat 60 degree water from a hose to 90 or 100 degrees (depending on the outside temperature).

This result was even better than what we expected, because we obtained almost all the heat we will need in the competition. With our results, we went back to a professor that confirmed that we will be able to reach the temperature needed for the competition when we scale the system to span the entire length of our solar array. Our design was a complete success! This project was really fun to work on and allowed me to learn a lot of useful engineering skills. Thanks for reading the first post from this series, more updates and stories on the progress of the house are soon to come!