J. ENVIRONMENTAL SYSTEMS, Vol. 28(4) 271-277, 2000-2001 ON MANAGING INDOOR AIR QUALITY IN HONG KONG W. K. CHOW The Hong Kong Polytechnic University ABSTRACT The local government of Hong Kong is going to implement new codes for controlling indoor air quality with the aim to provide a better environment. Different views were collected from the public on what should be done to give a good built environment. A wide area of application was proposed for the building management team to follow. However, the part on spaces with mechanical ventilation and air-conditioning (MVAC) system is not adequate. In this article, key aspects of indoor air quality for spaces with MVAC systems are discussed. Items that should be included in the new code are also outlined. INTRODUCTION Buildings should be designed with adequate ventilation for comfort, health, and satisfaction of building occupants. When natural ventilation cannot be provided satisfactorily, as in most non-residential buildings in Hong Kong, Mechanical Ventilation and Air-Conditioning (MVAC) systems are installed [1]. The primary objective of installing an MVAC system is to provide occupants with a healthy and comfortable indoor environment for carrying out their activities [2]; or to provide the required indoor environmental control for manufacturing (e.g., textile mills, electronic factories), product storage, or other development processes. However, surveyed results on local MVAC systems [3, 4] illustrated that the MVAC system is installed essentially to satisfy the thermal comfort requirement. This is typical for those office buildings with high rental price, however, it is only one of the purposes of providing those systems. A “gap” was found between the design and the preference on MVAC systems. Macroscopic numbers such as the number of air changes per hour, N ACH , were specified in designing those systems. 271 Ó 2001, Baywood Publishing Co., Inc.