What is this image showing us and why should we care? Learning Objectives By the end of this lesson you should... Explain what a “u-value” is and apply the idea to insulating homes and other buildings. Design an experiment to determine the U-values of different insulators to find the most effective. Explain how insulation methods in the home prevent heat loss. What is this image showing us and why should we care?
Thermograms & Heat Loss Learning Objectives By the end of this lesson you should... Explain what a “u-value” is and apply the idea to insulating homes and other buildings. Design an experiment to determine the U-values of different insulators to find the most effective. Explain how insulation methods in the home prevent heat loss. Thermograms & Heat Loss Thermogram image – Green = Cool Red = Warm White = Hot Notice there are heat “losses” at all points – even through the walls.
Learning Objectives By the end of this lesson you should be able to… Explain what a “u-value” is and apply the idea to insulating homes and other buildings. Design an experiment to determine the U-values of different insulators to find the most effective. Explain how insulation methods in the home prevent heat loss.
Moving Energy Thermal energy always flows from _____ to ______. Learning Objectives By the end of this lesson you should... Explain what a “u-value” is and apply the idea to insulating homes and other buildings. Design an experiment to determine the U-values of different insulators to find the most effective. Explain how insulation methods in the home prevent heat loss. Moving Energy Thermal energy always flows from _____ to ______. This will continue until any two objects are at the same _________ – this point is called thermal equilibrium This unwanted flow of energy can be reduced by insulation. Without effective insulation this flow of energy from the warm inside of our houses to the colder outside would mean that the price paid for heating would be huge.
Learning Objectives By the end of this lesson you should... Explain what a “u-value” is and apply the idea to insulating homes and other buildings. Design an experiment to determine the U-values of different insulators to find the most effective. Explain how insulation methods in the home prevent heat loss. Insulating What methods do we use to prevent thermal energy “loss” from our homes?
Insulating Cavity Wall Insulation Loft Insulation Curtains and blinds Learning Objectives By the end of this lesson you should... Explain what a “u-value” is and apply the idea to insulating homes and other buildings. Design an experiment to determine the U-values of different insulators to find the most effective. Explain how insulation methods in the home prevent heat loss. Insulating Cavity Wall Insulation Loft Insulation Curtains and blinds Draft excluders Double glazing Reflectors on walls behind radiators Hot water jackets Many more! All will prevent energy loss but to a large extent their effectiveness will depend on what materials are used.
Learning Objectives By the end of this lesson you should... Explain what a “u-value” is and apply the idea to insulating homes and other buildings. Design an experiment to determine the U-values of different insulators to find the most effective. Explain how insulation methods in the home prevent heat loss. U-Values A U-value is a measure of how effective an insulator a material is. The lower the value, the better the insulator
Learning Objectives By the end of this lesson you should... Explain what a “u-value” is and apply the idea to insulating homes and other buildings. Design an experiment to determine the U-values of different insulators to find the most effective. Explain how insulation methods in the home prevent heat loss. U-Values The units are W/m2 Therefore a material with a U-value of 1 will allow 1J of energy, in 1 second, through 1 m2 of space.
Learning Objectives By the end of this lesson you should... Explain what a “u-value” is and apply the idea to insulating homes and other buildings. Design an experiment to determine the U-values of different insulators to find the most effective. Explain how insulation methods in the home prevent heat loss. Design an experiment which would allow you to calculate the U-values of different insulating materials
Material used for insulation Temperature in °C At the start After 5 minutes After 10 minutes After 15 minutes After 20 minutes No insulation Bubble wrap granules Newspaper Polystyrene Sawdust
Analysing Results 8. Plot cooling curve graphs for each material with: Learning Objectives By the end of this lesson you should... Explain what a “u-value” is and apply the idea to insulating homes and other buildings. Design an experiment to determine the U-values of different insulators to find the most effective. Explain how insulation methods in the home prevent heat loss. Analysing Results 8. Plot cooling curve graphs for each material with: ‘Temperature in °C’ on the y-axis ‘Time in minutes’ on the x-axis 9. Use your graphs to determine which material is the best insulator. Extension: If the U-value is rate of energy loss, per m2, can you calculate the U-value for the most insulating material? *hint you will need to calculate the surface area of the beaker
Can you complete the giant Tarzia? Learning Objectives By the end of this lesson you should... Explain what a “u-value” is and apply the idea to insulating homes and other buildings. Design an experiment to determine the U-values of different insulators to find the most effective. Explain how insulation methods in the home prevent heat loss. Can you complete the giant Tarzia?