Removal performance of formaldehyde by ceiling tiles as sorptive passive panels

In this study a ceiling tile (CT) was selected as a sorptive passive panel, and the effect of environmental conditions on its formaldehyde removal efficiency was evaluated. Experiments were performed in a 0.4 m3 chamber with the air flow rate of 0.2 m3 h−1, the air exchange rate of the 0.5 h−1, and the loading ratio of 0.23m2m-3. The range of temperature humidity levels varied between 21 °C ± 2 °C–26 °C ± 2 °C, and 30% ± 5%–75% ± 5%, respectively, to simulate the indoor conditions for Canadian homes during most months of the year. Results demonstrated formaldehyde removal efficiency between 40% and 75% depending on the applied environmental conditions. GC/MS and HPLC trace analyses revealed that only very low concentrations of by-products were formed. The by-product formation increased slightly when exposing the ceiling tile to relatively high relative humidity (RH = 75%) and temperature (T = 26 °C). Given a loading factor of only 0.23 m2 m−3in our test chamber, which in most scenarios underestimates the loading factor in real settings, our findings suggest that ceiling tiles used as passive removal panels have the potential to lower formaldehyde concentrations under the Health Canada's guideline for residential settings under real-life conditions.