Heat energy is transferred from homes by conduction through the walls, floor, roof and windows. It is also transferred from homes by convection. For example, cold air can enter the house through gaps in doors and windows, and convection currents can transfer heat energy in the loft to the roof tiles.
Convection is the heat transfer due to the movement of a fluid, such as a gas or liquid, and carries heat energy away from the source of heat. When a substance is heated, it causes its particles to vibrate more. The more vibration, the more space they will take up and the less dense they will become.
