Evaluation of foamed nickel photocatalytic filters for an air cleaner on removal of formaldehyde in the indoor environment

Abstract

Foamed nickel photocatalytic filters based on zinc oxide and fitted to standard air cleaner are assessed under the same indoor air quality conditions in a real test site setting with UV light applied via a suitable lamp. Environmental parameters determined using a chamber test are input to the mass balance model and airflow analysis software (CONTAM) to simulate the change of HCHO concentration with time at the real test site. The mass balance model is validated by mean absolute percentage error (MAPE). Results of the environmental control chamber test for ZnO filters at 60 min interval show the highest removal efficiency for HCHO are under no UV light irradiation. It also shows that regardless of whether the UV lamp is on or off, the highest removal efficiency for HCHO is under high humidity and low concentration. The removal efficiency of HCHO with application of UV light is not significantly affected by low humidity and low concentration. Clean air delivery rates (CADR) of the air cleaner are consistent with HCHO removal efficiency, i.e., higher CADR brings higher removal efficiency. The results show the removal efficiency of HCHO by TiO2 photocatalytic filters is higher than that obtained with ZnO photocatalytic filters under UV light irradiation. For the real test site, the MAPEs of the simulations are 13.52 ~ 38.80% for changes of HCHO concentrations in 20 min interval with mass balance model and CONTAM. The MAPEs of HCHO for CONTAM simulations is 5.38%, which shows the CONTAM has good.