SE-14-C028 -- Multizone Particulate, Formaldehyde and VOC Measurements in Two Lab Houses Under Operation of Different Whole-Building Ventilation Systems PDF

This study focused on the in-situ impacts of various whole-building dilution ventilation systems, including the impacts of differing sources of outside air and the levels of particle, formaldehyde, and other volatile organic compound (VOC) contaminants in two interior zones. The project involved testing two single-family homes in Tyler, TX that were constructed as lab homes at the University of Texas at Tyler. Exhaust ventilation testing showed higher concentrations of particulates, formaldehyde and Top 20 VOCs compared to testing under the supply and balanced ventilation systems. The central-fan-integrated supply (CFIS) ventilation system showed an 85% and 73% reduction in 0.3 to 2.0 micron particles for House 1 and House 2, respectively. This was attributable to ventilation air filtration and recirculation air filtration by operation of the central air distribution system. The CFIS and Energy Recovery Ventilator (ERV) systems showed a significant reduction in formaldehyde concentration over the Baseline, and a large 60-70% reduction in formaldehyde concentration over Exhaust. Total VOC (TVOC) measurements showed that the CFIS and ERV ventilation systems reduced TVOC by 47% and 57%, respectively, compared to the Exhaust system as averaged between the two houses. Compared to the Baseline tests, in which no ventilation was operated, the Exhaust system increased TVOC by 37% in the House 1 Main zone, and increased TVOC by 18% in the House 2 Master zone. These particulate and TVOC results highlight that the unknown source of outside air and air entry path for the Exhaust ventilation system can cause indoor air to be more contaminated depending on what contaminants are picked up as the air comes through the building enclosure. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering that air.