Indoor air-pollutant reduction performance of photocatalytic ventilation system in apartments

In apartments and buildings, dilution ventilation systems are traditionally used to improve the air quality and reduce dust and pollution. However, this is not feasible without various filter systems if the outdoor air is not clean. Korea's atmosphere contains ultrafine dust and various gaseous pollutants. Therefore, the use of air cleaners or ventilation systems with dust collection and activated carbon filters to improve indoor air quality has recently increased. However, traditional dust collection and activated carbon filters exhibit limited performance in removing gaseous pollutants in homes. Photocatalysts remove gaseous pollutants; therefore, a model combining a titanium dioxide (TiO2) photocatalytic reactor and mechanical ventilation system, which is mostly applied in new apartments in Korea, was proposed. The performance of indoor pollutant removal was assessed through mock-up tests, and it was verified that formaldehyde (HCHO) could be reduced by at least 35.48% (with 1ACH (air change per hour) over 150 min) and toluene (C7H8) by at least 39.95% (with 1ACH over 300 min). Thus, it is anticipated that if the photocatalytic ventilation system is applied to apartments, it will provide enhanced performance in the removal of various indoor pollutants.