An analysis of electricity end-use in air-conditioned office buildings in Hong Kong

There has been a growing interest in the electrical end-use patterns in air-conditioned commercial buildings in Hong Kong. A total of four high-rise fully air-conditioned office buildings were selected as case studies. The total building electrical load was broken down into four major electricity end-users, namely heating, ventilation and air-conditioning (HVAC), lighting, small power and lift/escalator. The hourly load profiles of these electricity end-users were monitored during the hot summer months of July and August. It was found that HVAC was the single largest electricity end-user, accounting for 30–60% of the total building electrical demand during office hours. Electric lighting was second with 20–35% and small power third with 15–25%. Lift/escalator accounted for a few percentage of the total building load. An analysis of the peak load revealed that chiller load was a major component. It was found that chiller load shifting using thermal chilled store could reduce the peak building load by about 20%.