P1.1.4 Heating and Insulating Buildings

Specific Heat Capacity You will (hopefully) learn that: The greater the mass of an object the more energy is required to raise its temperature. The material it is made from affects the amount of energy required to heat it. Each material has its own ‘specific heat capacity’. Storage heaters rely on substances to store and transfer energy.

Specific Heat Capacity (little ‘c’) The specific heat capacity is the energy needed to raise the temperature of 1 kg by 1oC E = m x c x θ E = Energy transferred in Joules [J] m = mass in kilograms [kg] c = specific heat capacity [J/kg/oC] θ = change in temperature [oC]

Tasks Answer the questions on the A5 sheet, showing all your working out. DO NOT WRITE ON THE SHEET Look in the text book and answer the summary questions on page 39 in full sentences.

Big ‘U’ Objectives: To be able to describe the construction of a solar panel. To explain how, and why, houses are insulated and the method by which heat transfer is reduced. Recognise big ‘U’. To calculate ‘payback’ time.

Answers to questions a) 25% b)

Answers to questions White. i) Insulating the roof because it has the shortest payback period. Ignore comments such as ‘it is the cheapest’, unless the time taken to recoup installation costs is discussed. White. iii) Walls thicker / cavity insulation / insulated / made from insulating material floors thicker / made from insulating material e.g. polystyrene, wood draught prevention /closing windows /closing doors / stop (hot) air escaping using curtains /shutters windows that face Sun / fewer windows reducing temperature inside house iv) Insulation traps air air is a bad conductor / good insulator or convection reduced in trapped air

Practicals Aluminium block connected to a SEP energy meter Model house