Balancing Clean Air, Energy Efficiency, and Occupant Health
How GDI Ainsworth’s tracer particle testing helped CBRE and Infrastructure Ontario optimize indoor air quality at the Orillia Courthouse.
Project Details
Location
Ontario, Canada
Number of Buildings
Multiple government facilities within a 260-acre campus
System Implemented
Tracer particle testing using ASHRAE Standard 241-2023 methodology to measure clean airflow delivery, air change rates, and ventilation effectiveness
Project Goal
Validate and optimize indoor air quality to support occupant health, ASHRAE 241 compliance, and energy efficiency
Impact at a Glance
Conducted 17 clean airflow tests using accredited tracer aerosol decay methodology
Identified 97% average excess VECAi, highlighting significant over-ventilation opportunities
Enabled fast, data-driven recommendations to reduce HVAC energy use while maintaining occupant health
Supported compliance with ASHRAE Standard 241 – Control of Infectious Aerosols
Challenge
The COVID-19 pandemic underscored the critical role of indoor air quality in occupant health, safety, and well-being. For large, government-managed facilities like the Orillia Courthouse, balancing clean airflow with energy efficiency posed a challenge. Without precise measurement, buildings risked either under-ventilation—compromising health—or over-ventilation—driving unnecessary energy use and emissions.
Methodology
Deployed accredited technicians to conduct tracer aerosol decay testing
Applied ASHRAE Standard 241-2023 normative methodology
Measured clean airflow delivery within the breathing zone
Calculated clean air delivery metrics (ECAi, VECAi) and effective air change rates (eACH)
Identified zones with excess or insufficient clean airflow
Analyzed results onsite to enable immediate recommendations
Solution
Performed run-fast, accurate clean airflow rate testing across occupied spaces and conducted 17 tracer particle tests to assess ventilation effectiveness
Quantified clean air delivery and air change rates at the zone level
Identified over-ventilated areas suitable for airflow reduction
Flagged under-ventilated spaces requiring adjustment for compliance and wellness
Enabled optimization of ventilation based on current occupancy levels
Supported energy savings, decarbonization goals, and occupant health simultaneously
The Ripple Effect
Reduced HVAC energy consumption by addressing over-ventilated areas
Improved confidence in indoor air quality performance for occupants and operators
Enabled data-driven decision-making aligned with evolving IAQ standards
Established a scalable approach to managing infectious aerosol risk and wildfire smoke exposure
