ASHRAE’s Indoor Air Quality Procedure (IAQP) provides building owners and design teams with a powerful alternative to prescriptive ventilation rates. Rather than relying on fixed outdoor air requirements, IAQP allows ventilation strategies to be based on verified contaminant control and demonstrated indoor air quality outcomes. Central to this approach is the selection of air cleaning equipment that can reliably, measurably, and defensibly remove contaminants of concern.
Choosing the right air cleaning technology for IAQP is less about brand or buzzwords and more about performance validation, documentation, and long-term reliability.
Start with Verified Removal Efficiency Data
Regardless of technology type, IAQP relies on measured contaminant removal, not theoretical performance. ASHRAE Standard 62.1-2022 explicitly requires that air cleaning devices used in performance-based ventilation be supported by manufacturer-provided removal efficiencies tested for Table 6-5 Design Compounds.
When evaluating air cleaning equipment, manufacturers should be able to clearly document:
- The test method used
- Removal efficiency by contaminant shown in percentages
- Airflow used for testing
If this data is unavailable or based on non-standardized testing, the technology may be difficult, or impossible, to defensibly apply within an IAQP framework.
Understand Technology Differences and Performance Implications
Air cleaning technologies vary significantly in how they remove contaminants and how consistently they perform over time.
Mechanical filtration systems, such as Certified HEPA, MERV rated filters, and molecular adsorbent media, physically remove particles and gaseous contaminants from the airstream. Their performance is well understood, repeatable, and easily quantified through standardized testing.
Other technologies, including electronic air cleaners and ionization-based devices, often rely on indirect mechanisms to reduce airborne contaminants. A recent independent study on ionization technologies highlights the importance of carefully evaluating claimed equivalent clean airflow rates and understanding how performance can vary based on operating conditions, space configuration, and contaminant type. While such technologies may offer benefits in specific applications, the study reinforces the need for transparent, standardized testing when applying any air cleaning method within IAQP.
(Reference: “Contextualizing Equivalent Clean Airflow Rates for Airborne Pathogens of Ionizers and Other Electronic Indoor Air Cleaners”)
The key takeaway is not that one technology is universally right or wrong, but that performance claims must be independently validated and directly applicable to IAQP calculations.
Align Air Cleaning with System-Level Strategy
Air cleaning equipment should not be evaluated in isolation. Its placement within the HVAC system, interaction with outdoor air strategies, and compatibility with controls and monitoring systems all influence IAQP success. Centralized, in-duct air cleaning solutions allow contaminants to be addressed at the system level supporting whole-building IAQ control.
Equally important are maintenance and operational impacts. Installation complexity, system downtime, and disruption to normal building activities should be carefully considered. Technologies that require installation at multiple points of use, frequent access to occupied spaces, or specialized servicing can increase labor costs and complicate long-term IAQP execution.
Ongoing maintenance requirements also matter. Filter replacement intervals, pressure drop impacts, and ease of access all affect system performance and operating cost over time.
Choose Transparency Over Promises
Ultimately, the most important factor in selecting air cleaning equipment for IAQP is transparency. Manufacturers should clearly explain how their technology works, provide current standard-compliant test data, and support engineers and building owners with the documentation needed for design, approval, and ongoing verification.
In performance-based ventilation, confidence comes from measured results, not assumptions. Selecting air cleaning equipment with proven, standardized performance helps ensure IAQP delivers on its promise: cleaner air, smarter ventilation, and energy-efficient buildings designed for real-world conditions.
