Building Hong Kong: Environmental Considerations

8. Design For Building Environmental Performance

lo r \ % Design For Building Environmental [ Performance Daniel Wai-tin Chan, John Burnett and Phillip Jones 1 INTRODUCTION Building Services Engineering At Stake Almost ever y summe r whe n w e pas s b y th e campu s o f Th e Hon g Kon g Polytechnic University , we ar e amuse d b y a slogan o n the wall o f the larg e staircase stac k whic h say s 'Betwee n Eleve n an d Three , Sli p Unde r a Tree' . Indeed, there is no place to hide from potentia l exposur e in the city of today. When we are enjoying the sunshine outdoors, we are warned that a high dose of ultra violet radiation (du e to the depletion o f the ozone layer) may induc e skin cance r o r ey e cataracts . I t i s n o safe r bac k indoors , hidin g withi n th e building fabric that is the 'weather modifier! We are then exposed to the potential ill effect s o f the sic k building syndrom e an d building-relate d illness . In th e first, buildin g service s engineer s ar e accuse d o f pollutin g th e outdoo r 152 I D.W.T . Chan, J. Burnett an d P. Jones environment by venting chlorofluorocarbon (CFC) , an ozone depletion agent , and excessiv e carbon dioxid e (fro m excessiv e energy consumption), a global warming gas, into the atmosphere. Building services engineers are responsible for the design, installation, operation and maintenance of the services systems that contribute to global environmental problems, and which are often unabl e to sustai n acceptabl e indoo r environmenta l conditions . With th e increasin g awareness o f environmenta l problems , bot h indoor s an d outdoors , buildin g developers an d end-user s hav e a highe r expectatio n o f the performanc e o f building services systems. This chapter reviews the conventional notion of the purposes o f building services systems in a building, and discusses innovativ e and more systematic approaches to improving on their performance . A Brief Moment I n Histor y In the 1960 s when Hong Kong started to develop its flourishing economy , airconditioned offices becam e the expected standard. Energy was cheap and was not a n issue to take into accoun t seriously . Indoor ai r might be cool or eve n cold, but it was also fresh. There was a notion that air-conditioned space had to b e cooled . Occupant s pu t o n jackets i n over-coole d spaces . Air was fres h because w e were generou s t o pum p i n sufficien t outdoo r air . The building s were loos e t o ai r infiltratio n an d th e architect s too k littl e car e t o control . Architects and interior designers used lighting of high intensities to highlight the interior and features o f the building. The oi l embarg o i n 197 3 triggere d a deman d fo r energ y conservation . Suddenly, the quantity of fresh air introduced into buildings was reduced to a barely acceptable level (2.5l/s/person) without considering it might jeopardize the indoo r ai r quality . Building s becam e tighte r t o reduc e ai r infiltration . Lighting levels were lowered without the compensation of using natural lighting. The demand in the 1970 s was for energy buildings. The over-responsive cut-back in the quest for reducing energy use induced many complaint s abou t th e indoo r environmen t a s manifes t i n al l kind s o f sickness. These complaints formed a category of its own when the World Health Organisation (WHO) described it as the 'Sick Building Syndrome' (WHO, 1983). However, Hong Kong did not then take note of the occurrence. Instead, building automation technolog y an d energ y management system s foun d a market i n Hong Kong. The general deman d wa s fo r th e so-calle d 'intelligen t building ' with the objectiv e o f better environmenta l contro l through distribute d direc t digital contro l systems . Unfortunately , withou t effectiv e training , technica l Design For Building Environmental...