IAQ and Connectivity - Before and After Multifamily Weatherization

Indoor air quality (IAQ) implications are important to consider for most energy focused building retrofits. The standard solution of using mechanical ventilation to dilute indoor contaminants with outside air is successful in many applications, but applying it to large multifamily properties poses some unique challenges. The interconnected systems and large shared interfaces between units results in potential for incoming makeup air to originate from neighboring units, potentially conveying contaminants and nuisance odors. Additionally the logistical issues of retrofitting ventilation fans into individual units when buildings are located in densely populated areas, can make these retrofits costly or otherwise challenging, especially in tall buildings with brick, block, or concrete envelopes.

This session will discuss findings from a field-study of multifamily buildings where IAQ metrics were measured for 2-week both before and after weatherization, and a series of advanced diagnostic blower door tests were conducted on each unit to measure overall leakiness and connectivity to neighboring units. Absolute levels and changes in contaminant concentration and inter-unit connectivity are discussed.

Results from this study will guide policy decisions on how multifamily retrofit programs can best comply with health and safety related IAQ requirements while achieving their primary goal of energy savings.