On-line hourly VOC monitoring in a low energy building: impact of building material emissions, outdoor sources and ventilation on ambient concentrations

摘要

While typical averaged pollutant levels for standard residential buildings are well reported in the literature, there is still a lack of time resolved concentration data. VOCs have been monitored both indoor and outdoor during two 15-day-campaigns into a French secondary school classroom. 61 hydrocarbons (C2-C12) and 25 oxygenated species (C2-C9) have been hourly measured by TD-GC-MS/FID, 10-min concentration profiles of 15 VOCs (from 33 to 181 uma) have been monitored by PTR-ToF-MS as well as formaldehyde have been measured by a portable analyser. Methanol, formaldehyde, toluene, acetone and acrolein are the main quantified species; their hourly concentrations vary in a large range from 1 to 37 ppb. Their concentration profiles are clearly indexed on the room ventilation rate; concentration declining when ventilation is turn on. Besides, other non correlated species such as benzene, xylenes or light hydrocarbons follow a different time profile and are correlated to outdoor pollution episodes.