reducing unwanted energy transfers

• Every person, animal and device transfers energy
• Much of that energy is supplied by electricity, which must be generated from other energy stores
• Some of these energy stores are renewable but most are non-renewable
• Unwanted energy transfers


  Energy transfers that are not useful, such as friction, electrical resistance, and unwanted sound energy
• Waste energy is energy that has been shifted into the environment and raises the temperature of the surroundings
• It is very difficult, if not impossible, to retrieve this waste energy from each individual air particle
• Dissipated energy


  The spreading out and transfer of energy stores into less useful forms, such as thermal energy causing the surroundings to heat up
• It is impossible to completely prevent unwanted energy transfer, the best that can be done is to reduce them
• Ways to reduce unwanted energy transfers

  1. Lubrication

  2. Thermal insulation
• Lubrication


  Reducing the friction between two surfaces to reduce unwanted energy transfer as heat
• Thermal insulation


  Reducing energy loss through windows, doors, walls and roofs to prevent unwanted energy transfer as heat
• Thermal conductivity


  A measure of how quickly heat will transfer through a material
• The lower the thermal conductivity of a material, the slower heat passes through the material