Home ventilation, IAQ, and asthma
Cost-effective approaches to upgrading residential mechanical ventilation systems to control indoor pollutants of both indoor and outdoor origin and improve asthma-related health outcomes
PI: Illinois Institute of Technology
Co-PI: Elevate Energy
The goal of this study is to investigate the effectiveness of three common approaches to upgrading residential mechanical ventilation systems in existing homes for reducing indoor pollutants of both indoor and outdoor origin, maintaining adequate environmental conditions and ventilation rates, and improving asthma-related health outcomes. The three types of ventilation systems to be investigated include: (1) continuous exhaust-only ventilation systems (single-point or multi-point as needed to meet ASHRAE Standard 62.2); (2) intermittent central-fan-integrated-supply (CFIS) ventilation systems with ERV/HRV units and automatic fan-cycler timers integrated into the existing air handling units; and (3) continuous balanced supply and exhaust ventilation systems with ERV/HRV.
The study is utilizing a crossover design with (i) four weeklong periods of indoor environmental data collection for approximately one year before the installation of mechanical ventilation systems, followed by (ii) four weeklong periods of IAQ and indoor environmental data collection for approximately one year after the installation of mechanical ventilation systems. The Elevate Energy team is administering standardized retrospective asthma outcome questionnaires to residents every month throughout the duration of the study, providing at total of 24 months of asthma outcome data collected over the course of two years.
Forty-five (45) low-income single-family and multi-family homes with at least one adult asthmatic resident in Chicago, IL were targeted for participation in the study, with a total of 47 homes being successfully recruited in 2017. The study homes are being divided into three test groups based on the ventilation system upgrades that they will receive; these are randomized to the extent possible, but also subject to other practical constraints as determined by the project team in consultation with the homeowners and contractors who will be installing the systems (e.g., existing system setup limitations, electrical access, etc.).
Results from the proposed research are expected to identify practical and effective commercially available systems that can (1) effectively dilute indoor generated pollutants, (2) minimize the infiltration of outdoor pollutants, (3) maintain adequate environmental conditions and ventilation rates, (4) reduce the prevalence of asthma-related health symptoms, and (5) achieve low life cycle costs for purchasing, installation, operation, and maintenance. The study will provide the first known data in the U.S. on asthma symptom outcomes and associations with different types of ventilation systems that are hypothesized to have highly varying impacts on indoor pollutant concentrations of both indoor and outdoor origin, environmental conditions, and ventilation rates. Results are expected to provide much needed guidance to homeowners, contractors, builders, and agencies such as HUD on the advantages and disadvantages of different types of residential mechanical ventilation systems.
This project is funded by the U.S. Department of Housing and Urban Development (HUD) through their Healthy Homes Technical Studies program (ILHHU0031-16).