Indoor Particle Characterization in Forty Commercial Building Offices in Singapore
ZURAIMI SULTAN, Jiayu Li, Jovan Pantelic, Stefano Schiavon,
UC Berkeley Abstract Number: 25
Working Group: Indoor Aerosols
AbstractLittle research has been conducted to study how office buildings protect occupants from exposure to particles of indoor and outdoor sources. Our research reports a cross-sectional empirical study involving weekly measurements of size-resolved indoor and outdoor particle concentrations in forty commercial building offices in Singapore. Indoor particle concentration was found to vary according to outdoor levels, particle-size, indoor particle removal rates, indoor particle of outdoor proportion (IPOP) and particle source strength. Indoor particle concentrations were significantly lower than outdoors, which indicates that the buildings have good indoor particle removal rates via filtration and ventilation, low indoor sources and low outdoor particle penetration through the ventilation system and building façade. Indeed, through generalized linear modelling analyses, indoor particle removal rate was found to be dependent on air distribution, use of supply air filters and paper utilisation. We found also lower IPOP for ultrafine than for fine particles via regression analyses of indoor and outdoor concentrations for each particle size. Daytime IPOP was significantly associated with air distribution and supply air filters while night time IPOP was lower in buildings with steel and glass facades. Lastly, regular daily cleaning was associated with lower particle source strengths. The contribution of outdoor sources was mainly seen for ultrafine and fine particles but less pronounced for coarse particles. We summarise that low indoor particle levels observed in Singapore office buildings is due to the effects of low indoor source contribution, low indoor particle of outdoor proportion and relatively high indoor particle removal rates.