Exploring Heat Transfer

To explore heat transfer and determine the best insulator, I filled 4 ceramic mugs with 6 ounces of hot water, which was 192 degrees.  I chose 4 different materials to cover each cup: foil, cotton cloth, paper towel and plastic bag.  I then waited thirty minutes and measured the temperature of the water again.  I predicted the foil would be a better insulator of heat because if I wrapped my cooked food in aluminum foil, the food will stay warm.

I found the cotton cloth was a better insulator of heat because after thirty minutes, the cup covered by he cotton cloth had the highest temperature.  The hot water in the cup covered with cotton cloth retained heat longer.  After thirty minutes, the cup covered in cotton cloth was 120 degrees, the cup covered in foil was 118 degrees.  The cup covered in paper towel was 112 degrees, and the cup covered in the plastic bag was 114 degrees.  I was surprised the cotton cloth was a better insulator of heat.  I guess it would make sense because there is a lot of air between the knitted material.  When I am cold, I usually put on clothes to keep warm, which is mostly made of cotton.

I would like to test different materials to see which ones would be better insulators.  I would like to test other fabrics like nylon, polyester, denim, corduroy, and wool.  I believe the best insulator of these materials would probably be wool.  I think wool is a better insulator because it is similar to cotton cloth is that it has air between the knitted material.  I also know that when I wear wool sweaters in the winter, I get overheated quickly.