Indoor air depolluting material: Combining sorption testing and modeling to predict product's service life in real conditions

Abstract

Indoor air quality is an important performance aspect in assuring a healthy and sustainable habitat. Building materials, occupant and related activity are some of the identified major indoor sources of formaldehyde, a high priority pollutant for indoor environmental health. Sorption materials embedded in gypsum wall and ceiling boards have been developed as an effective solution on the market to reduce the formaldehyde concentration levels indoors. A question often raised is the service life of the solution through time. This paper presents a methodology that combines sorption testing in small and full-scale chambers with mathematical modeling to provide a lifetime estimation on an industrial board in the frame of a collaborative work involving a material supplier (Saint-Gobain), university researchers (Syracuse University) and an independent testing and certification body (UL). This novel methodology is a combination of short- term & long-term performance assessments at chamber and room level using Certification laboratory reports or internal small-scale chamber sorption testing with CLIMPAQ tools to feed an analytical predictive model allowing extrapolation of service life. The predictive model accounted for the sorption characteristics of the Activ’Air® plasterboard with no additional finishing obtained from the small-scale chamber testing, the convective mass transfer resistance over the material surfaces and typical indoor formaldehyde pollution load condition, and was validated with full-scale experiments under ventilation conditions typical of ventilated spaces in residential and commercial buildings. Results show that the plasterboard tested is effective in removing formaldehyde over 50 years under realistic ventilation and standard average pollution load conditions.