Indoor Air Quality (IAQ) improvements using biofiltration in a highly efficient residential home

Abstract

Americans spend the majority of their time indoors where levels of pollutants may run two to five times-and occasionally more than 100 times-higher than outdoor levels [1]. Many of these pollutants can cause adverse health reactions in building occupants, which can contribute to lower worker productivity and increased sick leave. Traditional methods of indoor pollutant control in sealed buildings involve the use of outdoor ventilation. Outdoor ventilation requires the intake of outdoor air, which must be heated or cooled to meet indoor temperature and humidity requirements. This represents between 10-20% of the total energy consumption of a building [2]. Even though past research has touched on incorporating actual biofiltration into building systems, there is little to no research on the incorporation of biofilters into energy-efficient residential dwellings. One of the first applications of biofiltration for energy-efficient homes was conceived close to 30 years ago [3]. Figure 1 shows an example of a particular design that could be piloted in a building system. Biofiltration research has gone through numerous stages over the past 30 years, including: focusing on plant research to determine which plants are the most efficient at filtering contaminants; refinements to the construction of biofiltration systems; and the air quality impact that biowalls have on buildings [4-15]. While significant time and effort has been spent on identifying the best plant combinations to filter the air in biofiltration systems, little effort has been made on analyzing the potential energy savings of these systems. If it is also shown that a particular biowall system has the potential to significantly reduce the energy consumption in residential and commercial buildings, which jointly represents more than 60% of the electric energy consumption in the United States [1], their subsequent installation in buildings will have more validity and merit. The purpose of this paper is to elucidate a novel application to be piloted using biofiltration as a means to manage indoor air quality in buildings, as well as to potentially reduce overall energy consumption.