4.3.Insulation

Unit 4 - Refrigerants

4.3.Insulation
Materials that retard or prohibit the flow of sound or heat or Electricity are called insulators or insulating materials. The heat and electricity are the main sources of power in large number of important operations, so a safe handling of these sources may be impracticable without the use of insulators.

Insulation is the name given to any material that helps the transfer of heat by any one or combination of three different modes of heat transfer. If an ideal insulation existed, it would be comparatively easy to refrigerate a space and keep it refrigerated. However there is no perfect insulation material. Insulation is not a positive barrier to heat flow but serves to retard the flow of heat. In all refrigeration systems, the surrounding are at the high temperature and the heat intends to travel from the surroundings to the refrigerated space which is kept at low temperature.

The important functions of the insulating materials are as follows,
  • It reduces the heat transfer
  • It prevents water vapour condensation on cold surfaces.
  • It adds strength to the walls and ceiling.
  • It gives smooth and better surface finish.
  • It can absorb vibration and sound.
The important characteristics of good thermal insulation,
  • It should not be affected by moisture.
  • It should be strong to prevent the heat.
  • It should have low factor of heat transmissions.
  • It should be used easily.
Last modified: Monday, 29 August 2011, 7:20 AM