Ventilation and IAQ in Homes Receiving Energy Efficiency Retrofits

Abstract

Residential energy efficiency programs in the United States have become increasingly aware of the need to consider the indoor air quality impacts of the energy-based measures that are implemented. This has resulted in a shift from referencing outdated ventilation standards to incorporating ASHRAE Standard 62.2. Because this shift has resulted in substantial concern from program implementers regarding the cost of increased ventilation requirements, research on any benefits of this change is warranted. This presentation provides preliminary data from such a study. This study, which is still underway, implements the older ventilation standard in half of the homes and the current standard in the other half. In all homes, building air leakage reductions are measured before and after retrofit, along with indoor concentrations of a number of common contaminants, including carbon monoxide, carbon dioxide, formaldehyde, total VOCs, radon, and humidity. Existing ventilation is characterized, and additional ventilation to meet the applicable ventilation standard is documented. In addition, health surveys are administered to the occupants before retrofit and a minimum of 6 months after retrofit. This presentation will discuss changes in contaminant concentrations from before to after retrofit, corrected for outdoor weather factors. These changes will be evaluated separately by which of the two ventilation standards was used. Additionally, the total ventilation rates for the two groups will be presented, and the contaminant concentrations will be analyzed based on total ventilation rate, including natural and mechanical sources. Results of the health surveys will not be presented because at this time the sample size of fully completed houses is too small to draw any preliminary conclusions. Because the study is still underway the data presented should not be considered as representing the final conclusions of the study.