Fu Hong Society Kwai Hing Vocational Development Centre Stage 1: Conduct preliminary IAQ assessment at the               vocational development centre Stage 2:  Ceiling mounted installation of 2 units of               IQAir HealthPro 250 & 1 unit of IQAir Cleanzone 5100                air purification systems to improve the indoor air quality               in the centre Stage 3: Kwai Hing Vocational Development Centre attained              Excellent Class under the Indoor Air Quality (IAQ)              Certification Scheme in Hong Kong