Why Ventilation Alone Isn’t Enough: The Role of Source Control in Indoor Air Quality
Every year on November 8, professionals across the world celebrate World Ventil8 Day, recognizing the vital role that ventilation plays in supporting health, comfort, and productivity in the built environment.
But ventilation alone cannot ensure healthy indoor air. Even the best systems cannot perform as intended if the air they move carries dust, debris, or microbial contamination. To achieve truly effective indoor air quality, ventilation must work hand in hand with source control, the process of removing pollutants at their origin.
What Is Source Control?
Source control is one of the most effective strategies for improving indoor air quality. By identifying and removing contaminants at their source, Facility Managers prevent pollutants from entering the air stream and circulating through occupied spaces.
In HVAC systems, that means addressing the buildup of dust, debris, and biological growth inside ductwork, coils, and fans. Over time, this buildup restricts airflow, reduces system efficiency, and allows contaminants to spread throughout the building. Cleaning those systems according to ACR, The NADCA Standard is a critical step toward maintaining clean, balanced, and efficient ventilation.
Ventilation Performance Depends on Clean Systems
Properly designed ventilation systems are only as effective as the condition of the components that deliver the air. When ducts or coils are dirty, the system must work harder to maintain airflow, and ventilation rates can fall below design levels.
NADCA’s peer-reviewed Energy Study quantified the impact of professional HVAC system cleaning. Results showed that cleaning can:
- Reduce fan energy consumption by 41–60 percent
- Improve supply airflow by 10–46 percent
These results demonstrate that clean systems not only enhance indoor air quality but also improve energy performance and occupant comfort, key priorities for Facility Managers.
The Role of ACR, The NADCA Standard
To ensure that HVAC cleaning and inspection meet measurable performance criteria, NADCA developed ACR, The NADCA Standard. Now in its 2025 Edition, ACR provides detailed guidance on assessment, cleaning methods, and verification of cleanliness in HVAC systems.
Following ACR, The NADCA Standard gives Facility Managers confidence that their systems have been properly cleaned and documented. It also provides a consistent framework for maintaining ventilation performance across multiple facilities or campuses.
Effective indoor air quality management rests on three pillars: source control, ventilation, and filtration. Each plays a critical role, but source control is the foundation.
By removing contaminants before they can enter the occupied space or clog filters, Facility Managers can:
- Reduce airborne particulate and microbial load
- Extend equipment life and improve reliability
- Support compliance with IAQ and energy standards
- Ensure ventilation systems continue to perform as designed
When combined with proper ventilation and filtration, source control creates a comprehensive, sustainable approach to healthy indoor environments.
Take Action This World Ventil8 Day
World Ventil8 Day is a reminder that clean air begins inside the systems that deliver it. As awareness of indoor air quality continues to grow, Facility Managers have an opportunity to lead by example.
This month, take a moment to look beyond airflow rates and design intent. Make sure your ventilation systems are clean, balanced, and verified to perform as intended. Find a trusted NADCA-certified professional at nadca.com and be confident your systems are delivering the clean air your building occupants deserve.
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