RACA Journal April 2026 RACA_Apr_2026 | Page 20

VENTILATION AND FILTRATION feature

COMFORT VERSUS HEALTH: THE EVOLVING PARADIGMS OF IAQ

Compiled by Eamonn Ryan

Smart EC fan technology optimises IAQ, efficiency and sustainability.

Indoor air quality( IAQ) has never been a static concept. From humanity’ s first encounter with fire to today’ s debates over ventilation standards, IAQ has reflected a persistent tension between comfort – what occupants can smell or tolerate – and health, what actually harms them over time. As Max Sherman argues in‘ IAQ Paradigms – The Next Generation’, the field is now at the threshold of another major paradigm shift, one that reframes ventilation not around odours or compliance, but around quantifiable harm.

LESSONS FROM THE PANDEMIC The COVID-19 pandemic reinforced the importance of ventilation and filtration in public health. ASHRAE’ s work during this period informed Guideline 42, integrating more research on outdoor air management, demand-controlled ventilation( DCV), and filtration for infectious aerosol control. The guideline helps practitioners apply lessons learned – such as verifying outside air rates, monitoring damper performance, and ensuring that DCV systems are correctly used and maintained.

Guideline 42 addresses several real-world operational challenges that extend beyond simply meeting design standards:

• Humidity control: Proper humidity management prevents mould growth, protects materials, and enhances comfort – particularly in humid or tropical regions.

• Building operation: Maintaining appropriate ventilation and pressurisation during periods of low occupancy prevents deterioration of air quality and costly remediation.

• Demand-controlled ventilation: The guideline clarifies the role of CO₂ sensors in DCV systems. While CO₂ is a useful indicator of occupancy, it is not the sole measure of IAQ. Effective systems integrate multiple sensor inputs to optimise airflow and maintain air quality.

Ultimately, Guideline 42 complements Standard 62.1 by translating IAQ science into practical, actionable measures. It offers a living framework that will evolve as new research and technologies emerge, particularly in the areas of filtration, sensor integration and advanced control systems.

For designers, building operators and facility managers, it represents a roadmap for achieving cleaner, healthier, and more resilient indoor air – an increasingly vital goal in every ventilation and filtration strategy.

ADVANCED FAN TECHNOLOGY AND THE FUTURE OF IAQ

By Francois Schoombie, technical and operational director, ebm-papst

Most ventilation systems are static in control philosophy or are not speed-controlled at all. EC technology makes integration into Building Management Systems( BMS) and speed control easy, thereby ensuring accurate Indoor Air Quality( IAQ), with actual operating parameters and ventilation rates fed back to the BMS or control system.

Francois Schoombie, technical and operational director, ebm-papst.

© RACA Journal

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