One of the mini projects we did for the outdoor classroom was build a solar hot water heater. Our goal was to heat as much water by as many degrees as we could in a set amount of time. My group and I designed the most successful heater in the class. We designed our heater based on certain information such as sun angles and which materials are good conductors and insulators.
Here is a picture of our initial sketch:
This is a sketch of our water heater. We went through many ideas but eventually settled on this one. This sketch includes measurements as well as the materials we used. We stuck to our plan so our final product is almost identical to the rough draft.
Here is a picture of our completed water heater:
For the base of our solar hot water heater, we used an aluminum tin. The water was held in the main compartment (plastic box). To help attract the sun and redirect as much heat/radiation as we could into the water, we used Mylar panels (cardboard wrapped in Mylar). The Mylar panels were placed at about a 65º angle so it would form a 90º angle with the sun for optimum heat on the water. We also used copper rods to help conduct heat into the water. The plastic box was also lined with Mylar for optimum heat reflection. The Styrofoam was used as an insulator to help trap the heat. Over the top of the box holding the water we had a layer of plastic wrap to help trap heat in.
We decided to heat 425 milliliters of water which was a lot compared to the rest of the class. The initial temperature of the water was 17ºC. After half an hour in the sun, the temperature was 25ºC. This gave us an 8 degree increase. That may not seem like a lot, but we heated a large amount of water so these numbers gave us a huge energy gain. Our water gained 14,232 Joules which was the most in both STEM classes. |