Effects of botanical air filtration on energy efficient homes

Brenton S Dunham, Purdue University

Abstract

The Biowall is a botanical air filter that is used to improve indoor air quality and potentially save energy in highly efficient residential buildings when compared to traditional mechanical ventilation systems. The central idea is to use the passive ability of plants to remove harmful contaminants from the air as it is recirculated back to the central HVAC system. A prototype Biowall was installed in Purdue's energy efficient home that was used in the 2011 Solar Decathlon Competition. This research evaluated a new and improved version of the Biowall in the Solar Decathlon house that has been permanently placed in the Chatham Square neighborhood of Lafayette, Indiana. Data acquisition systems were used to measure VOC, CO2, temperature, and relative humidity levels of the air before and after passing through the Biowall. This data was used to calibrate a mathematical model of the heat and mass transfer of air flowing through the Biowall and HVAC system. The model provides an accurate representation of Biowall performance over a range of operating conditions. The model suggests that the Biowall does not require extra dehumidification and thus uses the equivalent amount of energy to that of an energy recovery ventilator. The modeling results also show that by improving the irrigation system for the Biowall it has the potential to use 25% less energy than the ERV. Results from this research demonstrate that the Biowall, integrated into the central HVAC system of an energy efficient home, can improve indoor air quality. This combined with the potential to reduce energy consumption results in an appealing ventilation system that could be used in many applications in the future.

Degree

M.S.

Advisors

Hutzel, Purdue University.

Subject Area

Mechanical engineering

COinS