Heat Transfer Flashcards
What is conduction
Conduction happens in solids as the heat energy causes more particles to collide. They vibrate more vigorously
What type of material is the best conducter
Metal
What do metals have that make them better at conducting
Free electrons (delocalised) that can make the energy move more quickly from the hot side to the cold
What is convection
The heat energy makes the particles move quicker and move further apart. Making them less dense. The dense liquid or gas will rise which forms convection current
Where does convection occur
In liquids and gassed
What does radiation emit in
Infrared waves
What direction do radiation waves travel in
All directions.
What surface absorbs radiation the best
Black
Which surface is poor emitters and absorbers
Shiny
What is the equation for payback time
Installation cost divided by annual savings
What type of insulation reduces heat loss
Conduction
What material acts as an insulator in the loft
Fibreglass wool
What reduces heat loss due to conduction
Double glazed windows
What reduces convection currents
Stopping draughts
What else reduces heat loss in a house
Floor insulation
