ISO 16890-2:2022

Overview

ISO 16890-2:2022 - "Air filters for general ventilation - Part 2: Measurement of fractional efficiency and air flow resistance" defines the laboratory test methods, equipment and procedures used to measure the fractional efficiency (particle-size dependent removal) and air flow resistance of particulate air filters for general ventilation. It is intended to be used together with ISO 16890‑1, ISO 16890‑3 and ISO 16890‑4. The procedure applies to test rigs with a nominal face area of 610 mm × 610 mm (24" × 24") and air flow rates from 0.25 m3/s to 1.5 m3/s. The standard covers filters with ePM1 ≤ 99% and ePM10 > 20% and is not applicable to portable room‑air cleaners.

Key topics and technical requirements

• Aerosol generation: Requirements for liquid (DEHS) and solid (KCl) test aerosols, their properties and generation methods.
• Test rig and sampling: Design, dimensions, air supply, mixing, upstream/downstream sampling and isolation for a 610×610 mm test section.
• Particle counting: Use of optical particle counters (OPC) including sizing ranges, calibration, zero-count and overload handling; single and dual-OPC test sequences.
• Air flow & resistance measurement: Procedures for measuring volumetric flow rates and filter pressure drop (resistance to air flow).
• Qualification & maintenance: Rig and instrument qualification tests (leakage, velocity uniformity, aerosol uniformity), routine checks and documentation.
• Data reduction & calculations: Correlation ratio, penetration and fractional efficiency calculations, background correction, quality requirements and reporting rules.
• Scope limits: Statistical validity requirements impose a minimum ePM10 ~20% for filters to be tested with this procedure.

Applications

• Product testing and development: Characterize filter performance (fractional efficiency vs particle size) and pressure drop for design optimization.
• Certification & quality control: Laboratory conformance testing for labeling filters under the ISO 16890 framework (ePM10/ePM2.5/ePM1 metrics).
• HVAC specification & procurement: Provide objective, comparable performance data for selecting filters in commercial and institutional ventilation systems.
• Indoor air quality (IAQ) research: Generate standardized aerosol filtration data for modeling particle penetration and system performance.

Who uses this standard

• Filter manufacturers and R&D labs
• Independent test laboratories and certification bodies
• HVAC engineers, building owners and facility managers
• IAQ consultants and researchers

Related standards

• ISO 16890‑1 - General principles and definitions (use together with ISO 16890‑2)
• ISO 16890‑3 and ISO 16890‑4 - Additional test procedures referenced by Part 2

Keywords: ISO 16890-2, air filters, fractional efficiency, air flow resistance, general ventilation, DEHS, KCl, optical particle counter, ePM1, ePM10, test rig.