Even though it is October, we have still had some pretty warm days here in Indiana. Not all of them have been sunny, but I’m still enjoying the warmer temperatures. More play time outside, sandals are still ok, and I can still easily take my class outside to do another science activity!
My 7th grade students were studying heat and energy. Specifically, we studied the ways heat transferred – radiation, conduction and convection. Obviously I wanted to incorporate food, and what better way to teach these concepts than to use ovens – solar ovens!
There are many ways to create a solar oven. I use leftover apple pie boxes from our school fundraiser, but most use pizza boxes or something similar. A few other simple supplies is all you need, besides whatever you plan to cook of course.
Here is a rundown of the science terms and why these boxes work:
Radiation – This is energy that travels as waves. This energy comes from the sun and drives the whole heating process of the oven.
Conduction – The radiant energy heats up the bottom of the box (black paper), and in turn, the black paper heats the air in the box.
Convection – The warm air rises up to the top of the box, pushing cooler air down in the process. The cooler air then gets heated from the bottom of the box, and since the box is closed, this cycle continually keeps the warm air inside.
You can find several youtube videos that explain the science behind solar ovens, as well as how to set them up. I’ve used these two videos in my classroom:
- This video by the SciGuys not only explains how to set up an oven, but also explains why they work! It fit perfectly into what I was trying to teach the students about these concepts.
- The other video is by Howcast and it shows a step by step tutorial of how to put the solar ovens together. I love showing my students this at the start, then replaying it one step at a time.
- Pizza box (or similar)
- Tin foil
- Plastic wrap
- Black paper
- Straw (Optional to prop box open)
- Food to heat! I use smore fixings – the chocolate melts great in these ovens! The marshmallow doesn’t toast, but it does get soft.
- Pair students up to make the boxes using the directions from the video
- Prepare whatever food item you would like them to heat. Even though students share a box, I prepare enough for each student to have their own smore.
- Find a spot outside in the sun and have students place their food inside their ovens. Make sure the ovens are allowing the sun to shine inside the boxes!
- Wait 15-20 minutes (I usually have a reading activity for students to do while they wait!)
- Enjoy the treats! (Napkins are also especially helpful here… smores are ooey, gooey!
Students absolutely love cooking in their solar ovens. Most want to bring the ovens home to see what else they can heat up!