Passive removal of indoor ozone by green building materials
Ozone is a known pollutant harmful to human health and a strong oxidizer. The use of Zero Energy Air Purification (ZEAP) materials has proven to be a viable option to reduce indoor ozone concentrations during short-term experiments. The current study focuses on activated carbon mats, and three green building materials (perlite-based ceiling tile, recycled carpet, and painted gypsum wallboard. The effects of long-term exposure of these materials to real environments on ozone removal capability, primary emissions (in absence of ozone) of carbonyls and secondary emissions of carbonyls following the use of ozone were studied. A field study was completed over a six-month period and laboratory testing was intermittently conducted on material samples. The results show sustained ozone removal capability for all materials except carpet. Carbonyl emissions are low for activated carbon in all field locations. Painted gypsum wallboard and perlite-based ceiling tile have similar overall emissions over the six-month period, but distributed differently in time, while carpet has large initial emission rates that decline rapidly but remain high compared to the other materials. This study confirms that activated carbon mats are a viable ZEAP material and that perlite-based ceiling tile could also be considered as such as it balances good ozone removal capability and low by- product emissions.