Noadswood Science, 2011

 To describe the effectiveness of insulation methods and to understand what an U-Value is Tuesday, February 02, 2016

 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)

 Reducing a home’s 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

 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 (£)

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

 The effectiveness of insulation is measured using u-values – the lower the u-value the more effective the insulating material… Double GlazingU-Value Standard2.8 Low-e Glass1.8 Low-e Glass & Argon Gas Cavity1.5  In this example the best double glazing is the low-e glass with argon gas cavity as it has the lowest u-value

 The thicker the insulation the lower the u-value…  Look at the table below – plot the results on a suitable graph… Insulation ThicknessU-Value 60mm mm mm mm mm mm mm0.23

 The data is continuous – requiring a line graph…

 Green loans – money saving over time…