For this project, we had to choose a previous project and redo it, making it better than before. My group chose the solar hot water heater, which was a mini project within our Outdoor Classroom design. I was very glad I got to redo this because the first time I did it there was several mistakes and our heat gain was one of the lowest in the class.
After many days of discussing possible options and testing different things, we finally chose a design. Our water heater is a aluminum foil pan covered in black plastic with copper pipes in the water. We also covered the top of the pan with saran wrap and made a reflector with mylar tape. In the end, our new project had a heat gain 10 times better than the average of our previous groups and 76 times better than my previous project. On the hottest day with our best design, our hot water heater got up to 70 degrees C and 158 degrees F. Our prior project heated up to only 18 degrees C (64.4 degrees F). The prior attempt was done in winter, while this one was done in summer, but the change in temperature is still very significant.
To see my previous solar water heater, click here =>
Heat - energy transfer via random molecular motions, resulting in gain or loss of internal energy Radiation - energy transmitted by electromagnetic waves Conduction - energy transfer from particle to particle within certain materials, or from one material to another when the two are in direct contact Convection - a means of heat transfer by movement of the heated substance itself, such as by currents in a fluid Insulation - lacking ability to transfer heat Sun Angles: The sun is at different angles at different times of year and day. Look at the picture below to see the angles for Novato, California. We kept these angles in mind when we were designing our water heater because we wanted the most vertical light to hit the water. Our reflector is angled to get the most sunlight at a around 8 to 9 in the morning in June. See the math we did in the presentation above.
Reflection
This project was a great chance to redo something that I didn't do the best on. I felt that I definitely rose to the challenge and made a really awesome water heater. It was cool to take what we already knew from experience and use it in an experiment/project. I didn't learn that much during this project because we already did it, but I learn good ways to design experiments and analyze the data we got. I also reviewed my knowledge of the sun and its angles. During this project, I felt we worked really well together. When we encountered a challenge or problem, we didn't give up, instead we had a sophisticated conversation about the best way to overcome it. This lead to us working fairly quickly through the project. I think we did a really good job communicating. We also set up good, simple experiments to find out one thing. Since each one only had one variable, we did a lot of them to figure out what worked and what didn't. One thing we could've done better is ran our experiments for longer to get more data. This would help us to be able to tell what was significant and important. Another thing that didn't go so well was our presentation. When we presented, it was one of the first times we had gone through it. But it went well so it worked out in the end. This project was probably my favorite project that we did, and it was a great way to end the year. I was really proud of how our water heater turned out and am really glad I had a chance to redo it.