The Heat is On

During this experiment I wanted to test how well various materials in the kitchen worked as insulators.  Tillery, Enger, and Ross explained that “Most insulating materials are good insulators because they contain many small air spaces,” which make the materials poor conductors because it is harder to conduct heat between the spaced out air molecules (2008).  With this in mind I chose four different materials to cover my coffee mugs of hot water.  I chose a coffee filter, pot holder, tin foil, and saran wrap as my insulators. 

            I felt that the pot holder would be a good insulator as we use it in the kitchen to protect our hands from hot materials, thus it should not be a good conductor of heat.  I also felt that the pot holder would contain many air pockets in the stuffing which complied with the earlier description of a good insulator.  I felt that the tin foil would prove to be a good insulator because we use it often to insulate our food once it is out of the oven.  I do not feel however, that it has many air pockets which contradict the description of a good insulator. The coffee filter and saran wrap did not seem as though they would be good insulators as there were no visible air pockets and from experience I noted that they are often good conductors of heat when covering hot objects.

            After waiting thirty minutes to test my hypothesis, my results came out as the tin foil being the best insulator keeping the water at a temperature of 116° C.  The coffee filter and pot holder tied, with the water at 113° C.  The thermometer dropped drastically when it was put in the water insulated by the saran wrap as it read 105° C.  Even though I did not visibly see air pockets in the tin foil I knew from experience that it was used to insulate food and thus was not surprised that it proved to be one of the better insulators.  I did think that the pot holder would be the highest insulator as it is used to protect our hands from heated things in the kitchen.  It was difficult to create a tight seal around the pot holder and the cup and I feel that there is a possibility that heat was lost due to this.  I was surprised that the coffee filter kept in as much heat as it did.  Although as stated earlier it might have tied the pot holder due to a loose seal.  When thinking about air pockets the coffee filter did have air pockets but they were so loose between the fibers that I felt the heat would easily escape.  The saran wrap was not incredibly surprising.  Although it is often noted the plastic can keep heat in as there is very little room for air to escape yet it can be a good conductor of heat because there are few air pockets and the heat can escape easily.

            It was interesting to complete this experiment using different material from the kitchen to see which ones were better materials.  It actually reminds me of an experiment/building project a cousin of mine conducted during which they used different materials to insulate each wall of a small cabin that they built to see which ones would be the best insulators for a future house that they were building.  Often in my mind I can think of different materials that are good insulators or conductors based on experience but I needed reminded of why they were good insulators or conductors.  I look forward to trying a similar experiment with my students.