MEPX
Chapter 6 of 10All chapters
  1. 1The simple machines
  2. 2Levers and gears
  3. 3Engines
  4. 4Hydraulics and pneumatics
  5. 5Getting power where it is needed
  6. 6Household machines
  7. 7Electric motors and generators
  8. 8Efficiency and losses
  9. 9Why machines fail
  10. 10Working out an unfamiliar machine

Chapter 6 of 10

Household machines

What is happening inside.

Heat pumps

A fridge, an air conditioner and a heat pump are the same machine. A fluid evaporates where you want cooling, absorbing heat, then condenses elsewhere and releases it.

  • The warm coils at the back of a fridge are where the heat is being dumped.
  • A heat pump can deliver several units of heat per unit of electricity, because it moves rather than makes heat.

Motors and pumps

Washing machines, vacuum cleaners and fans are motors driving a drum, an impeller or a blade. Most repairs are bearings, belts, filters and seals rather than the motor itself.