1. Home Insulation & U-Values
Noadswood Science, 2011

2. Home Insulation & U-Values
Friday, September 29, 2017
Home Insulation & U-Values
To describe the effectiveness of insulation methods and to understand what an U-Value is

3. Energy Bills
Which of the following houses would you expect to have the highest energy bills?
The house on the right has the highest energy bills as it is wasting the most to the surroundings (as shown by the thermal image)

4. Reducing heat loss
Reducing a homes heat loss saves a huge amount of energy and money – although this can be expensive initially the gains long time outweigh the initial offset…
Loft insulation
Double glazing
Cavity wall insulation
Draft excluders
Underlay and thick carpets
Insulation of pipes

5. Payback time (years) = cost of insulation (£)
Which method is best?
Which insulation method is best and how can you decide this?
Insulation cost / savings ratio is worked out using payback time – the amount of time it takes you to get your money back in savings…
Payback time (years) = cost of insulation (£)
savings per year in fuel costs (£)

6. Low-e Glass & Argon Gas Cavity
U-Values
The effectiveness of insulation is measured using u-values – the lower the u-value the more effective the insulating material…
Double Glazing
U-Value
Standard
2.8
Low-e Glass
1.8
Low-e Glass & Argon Gas Cavity
1.5
In this example the best double glazing is the low-e glass with argon gas cavity as it has the lowest u-value

7. Questions How can energy transfer be prevented from your house?
What is a solar heating panel?
How does it work?
Complete the summary questions

8. U-Values The thicker the insulation the lower the u-value…
Look at the table below – plot the results on a suitable graph…
Insulation Thickness
U-Value
60mm
0.46
70mm
0.41
80mm
0.37
90mm
0.34
100mm
0.30
110mm
0.26
120mm
0.23

9. Payback Time
Work out the payback time for the following (remember payback time (years) = cost of insulation (£) ÷ savings per year in fuel costs (£)
Method of insulation
Cost (£)
Savings per year (£)
Payback time (years)
Cavity wall insulation
£350
£100
3.5 years
Lost insulation
£150
1 year
Double glazing
£5000
£200
25 years
Insulation of hot water tank
£60
£15
4 years
Draught-proofing
£50
3.4 years

10. U-Values
The data is continuous – requiring a line graph…

11. Energy
Green loans – money saving over time…