PISB Bio Wall Top. Photo taken by Sean Corbett.
The air in indoor environments is contaminated by chemicals emitted from the materials, activities, and even the occupants of the building. Many of these chemicals are VOCs, which can promote chronic health problems such as cancer and “sick building syndrome,” along with decreased productivity. Typically indoor air is diluted with fresh, outdoor air to reduce pollutant levels; this is a very costly process that requires heating or cooling the outdoor air to achieve a comfortable indoor temperature. And while adsorptive filters can perform a role similar to that of the biowall microbes, these filters simply trap the harmful chemicals, requiring frequent replacement and disposal.
The biowall technology has been shown to yield indoor air that approaches the quality of fresh air from the rural outdoors and can generate between 1600 and 3000 cubic feet of “outside air “per minute. This is enough fresh air to meet two thirds of the fresh air requirements of 300-600 people, depending on the operation of the biofilter and the ongoing activities in the space (Nedlaw). Thus, the biowall offers a sustainable approach to promoting a healthier indoor environment—one that is green in both a literal and environmental sense.