P7.2.4 - Walls and insulation Flashcards
1
Q
What does the rate at which heat energy is transferred through a wall depend upon?
A
- Temperature difference between the 2 sides of the wall
- Area of walls
- Thickness of the walls
- Material of the walls
2
Q
The greater the temperature between the 2 sides of the wall…
A
the greater the rate of heat energy transfer
3
Q
The greater the area of the walls…
A
the greater the rate of heat energy transfer
4
Q
The thicker the wall…
A
the slower the rate of heat energy transfer
5
Q
The lower the thermal conductivity of the wall…
A
the lower the rate of heat energy transfer
6
Q
What is thermal conductivity?
A
A property of a material that measures the rate of energy transfer through a material
7
Q
What does thermal conductivity tell?
A
It tells you how quickly energy is transferred through a wall with:
- an area of 1m
- a thickness of 1m
- a temperature difference across it of 1C
8
Q
Suggest 2 reasons why a homeowner would want to insulate the walls of his house.
A
To reduce heat loss, such that…
- Heating does need to be switched on as much, saving energy
- Not as many fossil fuels need to be burnt for energy, leading to less global warming
