P2.5 Heating and insulating buildings

Question 1

What does fibre glass do?

Answer 1

Fibreglass can reduce the rate of energy transfer through the roof - since it is a good insulator

Question 2

How do loft insulation reduce the rate of energy transfer?

Answer 2

Having great number of layers of insulation - the thicker the insulation will be - so less energy transfer by conduction

Question 3

What do cavity wall insulations do?

Answer 3

Reduce the rate of energy transfer

The cavity of an outer wall is the space between the 2 layers of brick that make up the wall

Question 4

How do cavity wall insulation reduce the rate of energy transfers?

Answer 4

It traps the air in small pockets - reducing the rate of energy transfer by conduction

Question 5

How do double - glazed windows reduce the rate of energy transfer?

Answer 5

They have two planes with dry air or a vacuum between the panes

The thicker the glass - the lower the thermal conductivity

Dry air good insulator and a vacuum prevents energy transfer by convection

Question 6

How do solar panels work?

Answer 6

Absorbs infrared radiation from the Sun and are used to generate electricity