2. Keeping Homes Warm 24 June 201624 June 201624 June 2016 © 2006 James Ferguson © Teachable and James Ferguson. Some rights reserved. http://teachable.net/res.asp?r=5707

3. Index BACK 1.Thermograph Thermograph 2.Energy Loss for a House Energy Loss for a HouseEnergy Loss for a House 3.Saving Energy Saving EnergySaving Energy 4.Way of Saving Energy Way of Saving EnergyWay of Saving Energy 5.Payback Time Payback TimePayback Time 6.Conduction Conduction 7.Convection Convection 8.Radiation Radiation 9.Energy Efficiency Energy EfficiencyEnergy Efficiency 10.Energy Efficiency Calculations Energy Efficiency CalculationsEnergy Efficiency Calculations Objectives Can-Do Tasks Can-Do Tasks Links & Resources Links & Resources © Teachable and James Ferguson. Some rights reserved. http://teachable.net/res.asp?r=5707

4. Objectives Interpret data and calculate cost savings of different energy-saving strategies. Interpret data and calculate cost savings of different energy-saving strategies. Explain in the context of the home: Conduction Convection Radiation (absorption and emission) Explain in the context of the home: Conduction Convection Radiation (absorption and emission) State and use the equation for energy efficiency. State and use the equation for energy efficiency. © Teachable and James Ferguson. Some rights reserved. http://teachable.net/res.asp?r=5707

5. Thermographs Thermographs are pictures which represent temperature using colours. White is the hottest Blue is the coldest Increasing temperature HOT COLD © Teachable and James Ferguson. Some rights reserved. http://teachable.net/res.asp?r=5707

6. Energy Loss from a House Roof 25% 25% Walls 35% 35% Floor 15% 15% Doors Windows10% © Teachable and James Ferguson. Some rights reserved. http://teachable.net/res.asp?r=5707

7. Saving Energy Insulating your home saves energy and money! £ £ £ £ £ £££££ Loft insulation Hot water tank jacket Cavity wall insulation Double glazing Thick curtains Draught-proofing © Teachable and James Ferguson. Some rights reserved. http://teachable.net/res.asp?r=5707

8. Ways of Saving Energy 1.Loft insulation Fibreglass ‘wool’ laid across the loft floor 2.Hot water tank jacket Lagging such as fibreglass wool 3.Cavity wall insulation Two layers of bricks with a gap between them containing insulating foam 4.Thick curtains 5.Draught-proofing Strips of foam and plastic around doors and windows 6.Double glazing Two layers of glass with an air gap between © Teachable and James Ferguson. Some rights reserved. http://teachable.net/res.asp?r=5707

9. Payback Time annual saving initial cost payback time =InsulationCost Annual saving Payback time Loft insulation £250£100 Tank jacket £60£20 Cavity wall insulation £600£150 Thick curtains £220£20 Draught-proofing£75£25 Double glazing £3,000£60 2.5 yrs 3 yrs 4yrs 11yrs 3yrs 50 yrs © Teachable and James Ferguson. Some rights reserved. http://teachable.net/res.asp?r=5707

10. Conduction Mainly occurs in solids. It is the process by which vibrating particles pass on kinetic energy to neighbouring particles.  Loft insulation  Hot water tank jacket  Cavity wall insulation  Double glazing All reduce heat loss by conduction. © Teachable and James Ferguson. Some rights reserved. http://teachable.net/res.asp?r=5707

11. Convection Occurs in liquids and gases (fluids). It is the process by which particles with more energy move from hot places to cooler places and take their heat energy with them.  Cavity wall insulation  Draught-proofing  Thick curtains All reduce heat loss by convection. © Teachable and James Ferguson. Some rights reserved. http://teachable.net/res.asp?r=5707

12. Radiation Occurs only in transparent substances. It is the process by which heat energy is transmitted as infrared waves. These travel in straight lines at the speed of light and can travel in a vacuum.  Thick curtains  Foil coating on main forms of insulation All reduce heat loss by radiation. © Teachable and James Ferguson. Some rights reserved. http://teachable.net/res.asp?r=5707

13. Energy Efficiency total energy input useful energy output efficiency = All appliances waste some energy. The efficiency of an appliance is a measure of how much energy it wastes. ENERGY INPUT USEFUL ENERGY OUTPUT WASTED ENERGY © Teachable and James Ferguson. Some rights reserved. http://teachable.net/res.asp?r=5707

14. Energy Efficiency Calculations useful output efficiency X total input 1.A kettle uses 200,000J of energy to boil 2l of water. It loses 12,000J to the room as heat. What is its efficiency? Step 1 Write equation total energy input useful energy output efficiency = Step 2 Substitute in the figures 200,000 188,000 efficiency = 0.94 efficiency = Step 3 Calculate answer 0.94 X 100 = 94% © Teachable and James Ferguson. Some rights reserved. http://teachable.net/res.asp?r=5707

15. 1.Copy and complete the table below: 4 marks P1 Keeping Homes Warm ENERGY FOR THE HOME  Homework  30mins approx Payback Time and Energy Efficiency InsulationCostAnnualSavingPayback Time (Yrs) Loft Insulation £400£80 Double Glazing £2,000£50 Cavity Wall Insulation £600£60 Draught Excluder £40£20 5yrs 40yrs 10yrs 2yrs Double Glazing a.Which type of insulation costs the most? b.Which type of insulation is the most effective? c.Which type is the most “cost effective”? d.Which type pays for itself after 40 years? Loft Insulation Draught Excluder Double Glazing 4 marks © 2006 James Ferguson © Teachable and James Ferguson. Some rights reserved. http://teachable.net/res.asp?r=5707

16. useful output efficiency X total input 2.An ordinary light bulb is 8% efficient. If it uses 1,000J of electrical energy how much energy is wasted as heat? 1 mark 1 mark Total 3 marks P1 Keeping Homes Warm ENERGY FOR THE HOME  Homework  30mins approx Payback Time and Energy Efficiency useful output energy =efficiency total input energy X useful output energy =0.08 X 1,000 useful output energy =80J waste energy = 1,000 - 80 waste energy = 920J © 2006 James Ferguson © Teachable and James Ferguson. Some rights reserved. http://teachable.net/res.asp?r=5707

17. useful output efficiency X total input 3.A gas boiler wastes 260J for every 1,000J of energy it is supplied with. What is the efficiency of this appliance? 1 mark 1 mark Total 4 marks P1 Keeping Homes Warm ENERGY FOR THE HOME  Homework  30mins approx Payback Time and Energy Efficiency efficiency = total input energy useful output energy efficiency = 1,000 740 efficiency = 0.74 efficiency = 0.74 X 100 = 74% 1 mark 1 mark How could the waste energy be reduced? Insulate the boiler and hot water tank, lag the pipes and service the boiler 1 mark 1 mark © 2006 James Ferguson © Teachable and James Ferguson. Some rights reserved. http://teachable.net/res.asp?r=5707