Insulation & energy transfer Flashcards
Describe the concept of insulation.
Insulation refers to preventing the movement of hear energy in or out of an object.
Explain how a solar water heater works.
Heat energy from the sun is used to heat up water flowing through black tubes or another substance that then heats the water.
What do ‘insulating materials’ do in a house?
Prevent heat loss in winter (keep house warm) or heat gain in summer (keep house cool).
What kinds of surfaces absorb heat most effectively?
Black, dull surfaces.
What is ‘wasted energy’?
Energy that escapes to the surroundings and does no useful work.
Describe ‘energy efficiency’.
A measure of how much input energy is converted into useful work.
How much chemical potential energy from coal is converted into useful electrical energy in a coal-fired power station?
Only about a third.
