1. P.1 Book E3 Section 1.5 Energy Efficiency Labelling Scheme Standby mode Hong Kong Energy Efficiency Labelling Scheme Saving energy Check-point 11 1.5Energy Efficiency Labelling Scheme

2. P.2 Book E3 Section 1.5 Energy Efficiency Labelling Scheme Standby mode In standby mode, appliances still consume energy.  >10% of the total residential consumption  1% of the world’s CO 2 emission Standby power accounts for Will you still switch appliances to standby mode instead of shutting them down?

3. P.3 Book E3 Section 1.5 Energy Efficiency Labelling Scheme 1 Hong Kong Energy Efficiency Labelling Scheme The Hong Kong Energy Efficiency Labelling Scheme (EELS) Promotes public awareness on energy-saving Helps select energy efficient products (e.g. compact fluorescent lamps, air-conditioners) Shows the energy performance of electrical products Two types: ‘Recognition Type’ & ‘Grading Type’

4. P.4 Book E3 Section 1.5 Energy Efficiency Labelling Scheme The ‘Recognition Type’ shows that the product has met the minimum efficiency specified in the scheme. 1 Hong Kong Energy Efficiency Labelling Scheme ‘Recognition Type’

5. P.5 Book E3 Section 1.5 Energy Efficiency Labelling Scheme The ‘Grading Type’ classifies the product’s energy performance into five grades (1 to 5). 1 Hong Kong Energy Efficiency Labelling Scheme ‘Grading Type’

6. P.6 Book E3 Section 1.5 Energy Efficiency Labelling Scheme The ‘Grading Type’ classifies the product’s energy performance into five grades (1 to 5). 1 Hong Kong Energy Efficiency Labelling Scheme ‘Grading Type’

7. P.7 Book E3 Section 1.5 Energy Efficiency Labelling Scheme Grade 1 : most efficient Grade 3 : about average Grade 5 : least efficient 1 Hong Kong Energy Efficiency Labelling Scheme ‘Grading Type’ Products are graded by calculating their energy eifficiency index (I  ): I  = actual energy consumption of the product average energy consumption of the products in the same category  100%

8. P.8 Book E3 Section 1.5 Energy Efficiency Labelling Scheme I  < 100%  energy efficiency greater than the average in that category (i.e. more efficient) E.g. For refrigerators: Example 10 Energy efficiency index 1 Hong Kong Energy Efficiency Labelling Scheme ‘Grading Type’

9. P.9 Book E3 Section 1.5 Energy Efficiency Labelling Scheme Example 10 Energy efficiency index (a)Refrigerator A consumes 742 kW h of energy per year. The average annual energy consumption for this kind of refrigerator is 823 kW h. Find the grading of refrigerator A. I  = actual energy consumption average energy consumption  100% = 742 823  100% = 90.2% ∴ Refrigerator A should be rated as grade 3. Table

10. P.10 Book E3 Section 1.5 Energy Efficiency Labelling Scheme Example 10 Energy efficiency index (b)Refrigerator B : same type as A, rated as grade 1 Find the min. percentage difference in annual energy consumption between A and B. ∵ I  of B  63% ∴ Min. difference corresponds to the indices of 63% and 90.2%. (i.e. If the annual energy consumption of B is 63 units, that of A will be 90.2 units.) Table

11. P.11 Book E3 Section 1.5 Energy Efficiency Labelling Scheme Example 10 Energy efficiency index = 90.2 – 63 90.2  100% = 30.2% Min. percentage difference ∴ Annual energy consumption of B is at least 30.2% less than A. (b)Refrigerator B : same type as A, rated as grade 1 Find the min. percentage difference in annual energy consumption between A and B.

12. P.12 Book E3 Section 1.5 Energy Efficiency Labelling Scheme a Making decisions based on energy labels Payback time Example 11

13. P.13 Book E3 Section 1.5 Energy Efficiency Labelling Scheme Example 11 Payback time Two labels are affixed on air-conditioners X and Y : Cost of electricity = $0.90 per kW h How many years will it take to payback the difference in price between X and Y with the savings on electricity? Air-conditioner X Price: $3400 Air-conditioner Y Price: $4000

14. P.14 Book E3 Section 1.5 Energy Efficiency Labelling Scheme Example 11 Payback time Energy saved per year = 1100 – 900 = 200 kW h Electricity cost saved per year = 200  0.90 = $180 Time to pay back = 3.33 years 4000 – 3400 180 = Air-conditioner X Price: $3400 Air-conditioner Y Price: $4000

15. P.15 Book E3 Section 1.5 Energy Efficiency Labelling Scheme 1 Saving energy a Pressure cookers ∵ Boiling point of water increases with pressure ∴ The water and food inside the vessel can reach temperature >100  C  Shorter cooking time  Less energy is needed A pressure cooker consists of a sealed vessel. During cooking, high pressure is built up inside the sealed vessel.

16. P.16 Book E3 Section 1.5 Energy Efficiency Labelling Scheme A vacuum cooker consists of a conducting inner pot and a vacuum insulated outer pot. Food in the inner pot is first cooked as usual. The inner pot is then put into the outer pot to keep the food hot without inputting energy.  Cook without a fire 1 Saving energy b Vacuum cookers

17. P.17 Book E3 Section 1.5 Energy Efficiency Labelling Scheme Reverse cycle air-conditioner (RCAC) Can act as a cooler and a heater The compressor pumps the refrigerant in the opposite direction.  Evaporator becomes condenser  RCAC acts as a heater (and vice versa). More efficient than a fan heater or oil radiator (save up to 1/3 of the energy) Safer (cannot cause burns or be knocked over) 1 Saving energy c Reverse cycle air-conditioners

18. P.18 Book E3 Section 1.5 Energy Efficiency Labelling Scheme Save energy in using lights: Replace incandescent lamps with CFLs.  More efficient Add dimmers to incandescent lamps to control the brightness.  The lamps can be turned dimmer when full brightness is not necessary.  Save energy 1 Saving energy d Lighting

19. P.19 Book E3 Section 1.5 Energy Efficiency Labelling Scheme For other electrical appliances, a plug-in timer can be used. It can set many different periods of operation for electrical appliances.  The device can be switched on and off automatically. Electrical appliances with built-in timers can switch on and off at appropriate times to reduce wastage. 1 Saving energy e Built-in timers and plug-in timers

20. P.20 Book E3 Section 1.5 Energy Efficiency Labelling Scheme Check-point 11 – Q1 A washing machine consumes 1.4 kW h of energy for a complete washing process. Average energy consumption in the same category is 1.3 kW h. Energy efficiency index I  (%)Energy efficiency grade I   80 1 80 < I   95 2 95 < I   110 3 110 < I   125 4 125 < I  5

21. P.21 Book E3 Section 1.5 Energy Efficiency Labelling Scheme Check-point 11 – Q1 Find the energy efficiency grade of this washing machine. =  100% 1.4 1.3 = 108% ∴ The washing machine should be rated as grade 3. I  (%)Grade I   80 1 80 < I   95 2 95 < I   110 3 110 < I   125 4 125 < I  5 actual energy consumption average energy consumption  100% = Energy efficiency index I 

22. P.22 Book E3 Section 1.5 Energy Efficiency Labelling Scheme Check-point 11 – Q2 (a)Switch off lamps when they are not in use. (b)Add dimmers to control the brightness of lamps. (c)Use compact fluorescent lamps instead of incandescent lamps. (d)Use lamps with Grade 5 labels. Can the following ways of using lamps save energy? Yes No

23. P.23 Book E3 Section 1.5 Energy Efficiency Labelling Scheme The End