Conduction

Heat Transfer by Conduction.

This type of heat transfer, conduction, happens in solids.

You should already have found out that heat is the sum of the kinetic energies of the particles within a substance. This energy gets shared out among all the particles in that object. The particles at the hot end vibrate vigorously, they bump and bounce off the particle next to them, this causes these particles to bump and bounce around, causing the particles ...... and so on until all the particles are bouncing at the same speed.

The heat is moved from one end to the other as buckets of water are handballed to a fire. Each particle take the heat and passes it on.

Insulation is the opposite of conduction. While in the process of conducting heat the material also resists some of the transfer of this heat. A perfect conductor is one that transfers all the heat put in one end and delivers it all without loss out the other end. A perfect Insulator is one that will not transfer any heat energy. No material (at least under normal conditions) is a perfect conductor or a perfect insulator. Materials are described as Conductors if they conduct heat better than most other materials and Insulators if they conduct heat worse than most other materials.

Some times we want to have materials that allow heat to move quickly (like when we are heating a room or cooking), other times we try to keep heat where it is, like in our houses or in our water tank. So we have to know how to measure the effectiveness of each type.

Qualitative comparison of rates of conduction through solids.

bring in samples of materials you think might keep in the heat.

Simple experiments.

what effect does

Calorimeter, a set sized box, thermometer,

Fill the Calorimeter with hot water, monitor the temperature over time while surrounded by the material of your choice.

Check out your materials with the following factors in consideration

  • wet/dry insulation,
  • thickness
  • volume of heat
  • difference in temperature

Other method could be to put in cold ice water, and to examine the material again, and examining the materials using the same factors.

U-values: use in domestic situations.

With the increasing cost of fuel insulation is becoming more important

U Values are a measure of the insulation of a body, more here ...

http://www.sei.ie/Schools/Secondary_Schools/Subjects/Physics/Unit_6_-_Heat_Transfer/U-Values/