Assessment of the Air Cleaning Performance and Humidity and Temperature Control by Five Evergreen Woody Plants

Abstract

Indoor air quality (IAQ) directly affects human health. The increase in PM and CO2 concentration indoors caused an increase in the prevalence of sick building syndrome (SBS) symptoms. Plants could contribute to reducing particulate matter (PM) and CO2. This study identifies the most efficient evergreen plant species for improving indoor air quality by assessing the ability of five different indigenous Korean evergreen plant species to reduce PM and CO2 and regulate humidity and temperature under indoor environmental conditions in acrylic chambers. The clean air delivery rates (CADR) were calculated to evaluate the efficacy of plants in reducing PM and CO2. We assessed the performance of removing the five study plants on PM1 (~0.68–3.01 m3/h/leaf area), PM2.5 (~0.73–3.08 m3/h/leaf area), PM10 (~0.67–3.04 m3/h/leaf area), and CO2 (~0.48–1.04 m3/h/leaf area). The species Ilex pedunculosa, Pittosporum tobira, and Gardenia jasminoides were the most effective at reducing PM. The CADR of CO2 also differed among the five plant species and corresponded to their photosynthetic rate. Viburnum odoratissimum var. awabuki, which had the high photosynthetic rate, was most effective at reducing CO2. By contrast, PM reduction was correlated with plant leaf structure. Plants with a high leaf density can accumulate more PM. The plants were also able to control temperature and humidity. The average temperature of the control chamber was higher, and the humidity was lower than that of the plant chambers. In this study, the five evergreen species effectively reduced air pollutants and can be used to improve IAQ.