Partners: Elevate, Illinois Institute of Technology
Initially funded by the U.S. Department of Housing and Urban Development, this study investigated the health impacts of installing mechanical ventilation systems in the homes of income eligible customers.
The Breathe Easy study began in December 2016. It was initially funded by the U.S. Department of Housing and Urban Development (HUD) in partnership with Elevate and Illinois Institute of Technology. The goal of the study was to investigate the ability of three distinct approaches to mechanical ventilation to improve indoor air quality in the homes of income eligible customers. In 2018, ComEd joined as a partner and co-funder of the study. With ComEd’s support, an evaluation of the ventilation systems on the building energy use and life cycle costs was layered into the study, as well as impact testing of the replacement of permanent split capacitor air handler motors with electrically commutated motors (ECM). ECMs are significantly more energy efficient and allow for variable run speeds.
The project team:
- Obtained participant asthma symptom data through IRB-approved health surveys
- Collected and analyzed data on indoor air quality and environmental conditions
- Collected data and evaluated the impacts of each ventilation system type on each home’s energy use
- Gathered the actuals costs of installation
This gathered information was used to develop a holistic understanding of the costs and benefits of the ventilation systems.
A total of 40 homes with 51 participants were retained until the end of the two-year-long study. The participating homes were low- and moderate-income, single- and multi-family residences with at least one asthmatic adult resident. Participants were divided into three groups to receive one of three different types of ventilation system upgrades. All systems were designed to provide minimum flow rates specified by ASHRAE Standard 62.2.
Results and Outcomes
The study team completed one year of pre-intervention data collection before installing the ventilation systems in participants’ homes. Researchers installed either continuous exhaust-only ventilation systems, intermittent central-fan-integrated-supply (CFIS) ventilation systems with automatic fan-cycler timers integrated into the existing air handling units (i.e., with the air handler operating 20 minutes out of every 60 minutes to meet 62.2 requirements) or continuous balanced supply and exhaust ventilation systems with energy recovery ventilator (ERV) units. The results showed a small improvement in asthma control across the entire population after the installation of each of the three ventilation types. However, only the impact of the CFIS ventilation systems was statistically significant. Adding these ventilation systems typically increased the energy used in the home as well as the customer’s bills.
Following the installation of the ventilation systems, the study team replaced the existing permanent split capacitor motors of the air handling units with ECMs in 16 of the 40 participating homes. Results indicated that the ECM updates mitigated the additional energy used by the CFIS ventilation systems. The study concluded that installing CFIS ventilation systems with ECMs could lead to increased air quality and a reduction in asthma impacts with a negligible change in energy costs.