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1. Loft insulation, cavity wall insulation, hot
water tank jacket, draught-proofing and curtains
are good heat insulators. They
reduce heat transfer by convection because they have trapped
air in them and air is a good heat insulator.
2. The
advantages of saving energy at home are:
a) It saves money.
b) Burning less fossil fuels causes less pollution (less damage to the
environment).
c) Reserves of fossil fuels are not use up too quickly.
3. Payback
time (years) = Cost of installation / Annual saving
4.
|
Type of insulation |
Cost
(£) |
Annual
saving (£) |
Payback
time |
|
Double glazing |
5000 |
50 |
50
years! |
|
Loft insulation |
300 |
60 |
5
years |
|
Cavity wall insulation |
600 |
100 |
6
years |
|
Draught-proofing |
50 |
50 |
1
year |
a) The type of heat insulation that pays for itself quickly is draught-proofing.
b) Double glazing is not a very cost effective method of heat insulation in a house as it has the
longest payback time.
c) The most effective method of heat insulation is cavity wall insulation
because it saves the most
money each year.
d) How Science Works
The type of
insulation is a categoric
variable.
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