The Effect of Photocatalytic Air Cleaning on Perceived Air Quality

An experiment was carried out to determine the effect of photocatalytic air cleaning on perceivedair quality. Thirty-eight subjects assessed the air quality in a low-polluting, 108 m3 office, with pollution sources either present or absent behind a partition. The pollution sources were carpet, linoleum and chipboard. The office was ventilated with outdoor air at 0.6, 2.5, and 6 h-1. The air temperature was 22C and the relative humidity 40%. For each condition in the office, sensory assessments were carried out with a photocatalytic air purifier, having 7 catalyst sections, turned on or off. With pollution sources present, the percentage dissatisfied with the air quality was reduced from 77% to 21% at 0.6 h-1, and from 32% to 6% at 2.5 h-1, when the air purifier was in operation. With pollution sources absent, turning the air purifier on at 0.6 h-1 reduced the percentage dissatisfied from 23% to 7%. With an airflow of 250 L/s through the air purifier, the calculated clean air delivery rates were approximately 4 h-1. The results imply that photocatalytic air cleaning can be a useful method for improving the air quality indoors.