ENERGY BENCHMARKS FOR VENTILATION SYSTEMS IN AIR-CONDITIONED OFFICES

Indoor environmental quality (IEQ), subjective satisfaction of occupants and energy conservation ofbuildings are usually determined separately. Since the energy crisis in 1973, engineers haveendeavored to implement energy conservation in buildings. Unfortunately, the effort resulted in energysavings without the fundamental delivery of indoor satisfaction in many cases. It is worthwhile todetermine a balance strategy between the potential energy saving and occupants satisfaction inworkplaces. Ventilation system is characterized to be one of the most significant components in annualenergy consumption. This study, which based on field measurement and questionnaire survey in 38sample offices, with acceptable temperatures and CO2 concentrations were used to examine theenergy consumption of annual thermal and ventilation system in Hong Kong. An energy benchmarkingmodel that related the major acceptable indoor parameters to building thermal energy consumptionwas established. The results showed that the energy consumed by a ventilation system would correlateclosely with the occupant generated carbon dioxide (CO2) concentration maintaining in the space, butits correlation with the air temperature set point would be less significant. The energy benchmarkingmodel would be useful for evaluating energy performance and promoting sustainability in buildingswithout any comfort penalty to the occupants.