1. Arch6026 - Building Systems II (2000/2001) Energy and Environmental Systems for Green Buildings Lecture 05 - Energy Efficient Technologies

2. Contents zTechnological Principles zPassive Building Design zBuilding Services Systems zSolar Energy Systems

3. Technological Principles zTechno + logical ysensible and effective use of technologies zEco-tech ylow-tech: less technical devices, more natural means (require precise analyses) ylight-tech: build much lighter and more flexible (reduce consumption and demand) yhigh-tech: newest, advanced techniques (* see pictures of buildings in the world)

4. Technological Principles zEnergy requirements ycooling energy (e.g. space conditioning) yheating energy (e.g. hot water) yelectrical energy (e.g. lighting) zEfficiency approach yreduce energy use & demand yoptimise energy supply & systems ytotal energy (e.g. combined heat & power)

5. Passive Building Design zBasic concept yinternal conditions are modified as a result of the behaviour of building form and fabric, without or with little mechanical assistance zTechniques ynatural ventilation ythermal storage in building fabric ydaylighting and sun control

6. Passive Building Design zCooling is the key question in HK zPassive cooling methods ycomfort ventilation (daytime) ynight ventilative cooling yradiant cooling (e.g. using roof or radiators) ydirect evaporative cooling (e.g. cooling tower) yindirect evaporative cooling (e.g. roof ponds) ysoil or earth cooling

7. Promote wind effect by wing walls Venting a thermal mass wall Examples of passive cooling designs Thermal chimney

8. Planted roofSecond skin façade

9. Passive Building Design zDaylighting options ysidelighting (e.g. side wall windows) ytoplighting (e.g. roof skylights) ycourtyards and light wells yatrium and greenhouse yoptical systems to collect, transport and distribute daylight (to inner spaces) xe.g. light pipes, holographic system

10. Lighting controls and daylighting sensor Daylighting sensor

11. Building Services Systems zHVAC system ymost important energy consumer yenergy saving techniques x‘free’ cooling methods xheat recovery xdistrict cooling/heating xcombined heat & power (CHP) xdesiccant-based cooling

12. ‘Free’ cooling methods in HVAC system (a) Air-side economiser cycle - intake more outdoor air when its enthalpy (energy content) is lower than indoor air (b) ‘Free’ refrigeration - chiller bypass when the system can be cooled by ambient Enthalpy line

13. Waste heat recovery - heat pump + chiller

14. Centralised refrigeration plant District cooling system (Do you know what are its advantages?) Individual buildings

15. Combined heat & power (also for district heating) Electricity supply Heat supply

16. Desiccant-based cooling system

17. Building Services Systems zLighting system ycompact fluorescent lamp (CFL) yelectronic ballast zOther building services systems yelectrical services ylifts and escalators ybuilding management system ywater supply system

18. Solar Energy Systems zCommon technologies yactive solar (e.g. solar hot water) yphotovoltaics (for electricity) zAdvantages yclean and renewable (reduce fossil fuels) ydecentralised and local resources zMore info about ‘renewable energy’ will be discussed in the coming lectures

19. Solar hot water system

20. Photovoltaic (PV) panels

21. Architectural integration of PV modules

22. Solar energy systems in Hong Kong Solar heating for a swimming pool complex PV system for a weather radar station