Home Insulation & U-Values

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

2. 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. 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. Payback Time • Work out the payback time for the following (remember payback time (years) = cost of insulation (£) ÷ savings per year in fuel costs (£)

7. U-Values • The effectiveness of insulation is measured using u-values – the lower the u-value the more effective the insulating material… • In this example the best double glazing is the low-e glass with argon gas cavity as it has the lowest u-value

8. U-Values • The thicker the insulation the lower the u-value… • Look at the table below – plot the results on a suitable graph…

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

10. Energy • Green loans – money saving over time…