Impact of ventilation on indoor air quality: Singular behaviour of formaldehyde

Combined with material emission, ventilation has a direct impact on volatile organic compound (VOC) concentrations in indoor environments. In this work, the impact of ventilation on various VOC emission rates relative to wood particleboard is assessed experimentally in a 128 L chamber. Ventilation characteristics have been varied (i) between 2.5 and 5.5 h-1 for the air exchange rate and (ii) between 0 and 1.8 m.s-1 for the air velocity in the vicinity of wood particleboards. Based on the results, the air velocity over the surface of the material is found to have no impact on emission of the eight VOCs monitored. However, our experimental work separate out the reduction of VOC concentration by dilution and the potential emission rate increment when air exchange rate is increased. For most VOC, increasing air exchange rate only induces a concentration reduction by dilution. But, formaldehyde exhibits a singular emission behaviour: the decrease in formaldehyde concentration with increasing air exchange rate is limited compared to other VOCs and the formaldehyde emission rate is observed to increase as a function of the air exchange rate. The input of new air thus appears to promote formaldehyde emission from the solid material. Given these results, IAQ prevention strategies have to take into account the specific behaviour of formaldehyde. Copyright © 2019, AIDIC Servizi S.r.l.