reducing energy loss

• What is the purpose of thermal insulation and lubrication?

  To reduce energy loss
• How can you suggest reducing energy loss in an exam question?

  By understanding the principles discussed
• What do most people prefer for their homes?

  A warm environment
• Why do we need to reduce heat energy escaping from homes?

  To maintain warmth inside
• What is convection?

  Heat transfer through liquids and gases
• How do foam seals help in a house?

  They prevent air from escaping
• What is conduction?

  Heat loss through solids
• How do thick walls help in reducing heat loss?

  They are made from low thermal conductivity materials
• What are cavity walls?

  Two layers of bricks with an air gap
• Why is air a poor conductor of heat?

  It does not transfer heat well
• What is the problem with air gaps in cavity walls?

  They allow convection to occur
• How is insulating foam used in cavity walls?

  It fills the gap with isolated air bubbles
• What is the difference between single and double glazing?

  Single has one pane, double has two
• How does double glazing reduce heat loss?

  It has an air gap that reduces conduction
• What is friction?

  Resistance when moving over a solid
• Why is reducing friction important?

  It increases the efficiency of energy transfer
• How can oil help in reducing friction?

  By acting as a lubricant
• How does streamlining vehicles help with energy efficiency?

  It reduces air resistance
• What is the benefit of reducing air resistance in vehicles?

  It allows them to use less fuel
• What are the main methods to reduce unwanted energy transfers?

  • Thermal insulation
  • Lubrication
• What adaptations do buildings have to reduce heat loss?

  • Sealed structures to prevent convection
  • Thick walls with low thermal conductivity
  • Cavity walls with insulating foam
  • Double glazing to reduce conduction
• What are the effects of friction on energy transfer?

  • Reduces efficiency of energy transfer
  • Causes objects to heat up
• How does lubrication affect mechanical systems?

  • Reduces friction
  • Increases efficiency of energy transfer
• What is the role of streamlining in vehicles?

  • Reduces air resistance
  • Improves fuel efficiency