Indoor air quality in mechanically ventilated residential dwellings/low-rise buildings: A review of existing information

Mechanical ventilation has become a mandatory requirement in multiple European standards addressing indoor air quality (IAQ) and ventilation in residential dwellings (single family houses and low-rise apartment buildings). This article presents the state of the art study through a review of the existing literature, to establish a link between ventilation rate and key indoor air pollutants. Design characteristics of a mechanical ventilation system such as supply/exhaust air flow, system and design of supply and exhaust outlets were considered. The performance of various ventilation solutions was assessed by comparing reported ventilation rates, concentrations of CO2 and total volatile organic compounds (TVOC) to minimum requirements defined by the latest version of the European Standard EN 15251:2007. Based on the literature review of these parameters, the authors noted that whenever the whole-house ventilation rate was reported below 0.5h-1 or 14 l/s·person in bedrooms, the concentrations of the pollutants elevated above minimum threshold limits (CO2>1350 ppm; TVOC > 3000 μg/m3) defined by the standard. Insufficient or non-existent supply of air was related to significantly higher pollutant concentrations. The authors additionally noted that the literature frequently reported the role of improper maintenance and use on deterioration of IAQ in residential dwellings. The summarized data and comments may provide useful information for future guidelines related to ventilation strategies designed for high IAQ in residential dwellings.