Effects of indoor plants on the physical environment with respect to distance and green coverage ratio

Abstract

Few studies have conducted experiments in daily living environments to examine the effects of indoor plants on objective aspects of the physical environment. This study examined the effects of plant distance and green coverage ratio on the objective physical environment and subjective psychological perceptions, along with the correlation between the objective physical environment and subjective psychological perceptions regarding indoor plants. A randomized control trial of plant distance and green coverage ratio was conducted in a room located in the basement of a university building in Taiwan. Aspects of the objective physical environment were measured using air quality detectors. Subjective psychological perceptions were evaluated based on the questionnaire responses of 60 undergraduates. The results revealed that (1) regardless of number of plants, the closer the plant, the higher the CO2 level; (2) more indoor plants resulted in higher CO2 and humidity and lower PM2.5, PM10, and temperature; and (3) the lower the levels of fine and suspended particles in the air were, the stronger were the feelings of preference, naturalness of the environment, and pleasure in participants. Indoor plants that can regulate indoor air quality and microclimates without consuming energy warrant greater attention and wider application.