Identifying Effects of Weatherization & Ventilation on Indoor Air Quality & Residential Occupant Health

Housing and health have been linked since the early days of modern public health. Florence Nightingale famously said “the connection between health and the dwellings of the population is one of the most important that exists.” Ventilation can reduce the concentration of contaminants in indoor air; however, it also removes heated (or air-conditioned) air. Efforts to increase residential energy efficiency due to rising energy costs and global climate change can alter the method and rate of ventilation in a home, impacting indoor air quality. This research was conducted as part of the larger Health and Environmental Aspects Linked to Housing Ventilation (HEALTH-V) study. In conjunction with the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE), the HEALTH-V study utilized a randomized control trial design in which participants’ homes were assigned to be weatherized in accordance with one of two common ventilation standards, ASHRAE 62-1989 and ASHRAE 62.2-2010. In this thesis, we investigated the effect of weatherization in accordance with the randomized ventilation standard on three indoor air contaminants—formaldehyde, total volatile organic compounds (TVOCs), and radon; and on selected health outcomes from the health interview. We found that weatherization and ventilation did have a significant effect on formaldehyde concentrations and some health indicators, including general health. We also found that in certain instances, the indoor air quality and health outcomes of participants whose homes were weatherized according to the ASHRAE 62.2-2010 standard had greater improvements relative to participants whose homes were weatherized according to the ASHRAE 62-1989 standard. We can conclude from this study that ventilation does have a significant effect on occupant health and indoor air quality, and that the ASHRAE 62.2-2010 standard appears to have significant health benefits for occupants when compared with the ASHRAE 62-1989 standard. The Society (ASHRAE) should continue to examine health studies to refine their standards to the existing body of research on health effects of ventilation and housing. Nationally, weatherization programs should incorporate a ventilation standard to ensure the weatherization assistance program continues to create a healthy environment for the inhabitants of weatherized homes.