I will explore heat transfer by investigating which material will best insulate water in a coffee mug. The investigation will involve filling 4 glass mugs with ¾ cup of hot water. I will then cover each mug with a different material and seal it with a rubber band. When choosing my materials, I tried to find both commonly used objects and those that were not typically associated with kitchen use. I chose a piece of velvet, a piece of fleece, a piece of aluminum foil, and a piece of plastic wrap. I hypothesized that the velvet would be the best insulator because it was a tightly woven thick material that would trap the most heat. I chose plastic wrap and aluminum foil because I commonly use them when trying to trap heat when cooking.
My investigation revealed that aluminum foil was the best insulator for stopping radiant heat loss. The aluminum foil held tight with a rubber band formed a seal that trapped the heat and kept it inside the cup. The trapped heat reflected off the shiny aluminum surface and back to the water causing the water to retain a high temperature. Although the aluminum foil felt hot, it did not let much heat escape. This trapping of air is the reason that thermoses are such good insulators of hot drinks and soups.
I thought velvet would be a much better insulator than fleece because velvet is tightly woven and thicker than fleece. I found that their insulating abilities were very similar. These results caused me to further explore why this happened. I investigated winter clothing. Upon reading further, I understood that fleece is a good layer of insulation between you and your clothes because it is full of air spaces that stop heat transfer. “Most insulating materials are good insulators because they contain many small air spaces. The small air spaces are poor conductors because the molecules of air are far apart, compared to a solid, making it more difficult to pass the increased vibrating motion from molecule to molecule” (Tillery, Enger, & Ross, 2008 p.86). This explains the warming qualities of wool and other fluffy fabrics. A velvet coat would trap heat from your body and make you feel warmer. But a velvet coat with a fleece lining would prepare you for especially cold winter conditions.
This investigation helped me understand that heat can be transferred through conduction, radiation and convection. Because heat is lost in these three different ways, different materials are required to stop the heat from leaving through conduction, radiation and convection. Foil is a good insulator to trap radiant energy, but is not a practical insulator for homes or people.


QUESTION OF THE DAY: How might you set up this or a similar experiment for students in your classroom? How could you make this experiment more fun, interesting, or engaging for your students? How might you design this experiment so that it is relevant to students’ lives?
I could set up a similar experiment for my students to explore heat transfer. This week we had a very hot field day and students were unhappy to find that their water bottles were not providing a cold drink of water. This circumstance would provide relevance for investigating different insulators. Students could test which insulator would best keep the 85 degree air from warming the water in their bottles. The students will investigate many materials and test them by taking them out in the hot sun for 30 minutes and measuring the temperature change. Students will then explore further to explain why certain materials worked better than others.