ISO 16890-4:2022

Overview

ISO 16890-4:2022 - "Air filters for general ventilation - Part 4: Conditioning method to determine the minimum fractional test efficiency" defines a laboratory conditioning procedure used to obtain the minimum fractional test efficiency of particulate air filter elements. Intended as a companion to the ISO 16890 series, this standard specifies test-device and conditioning-cabinet requirements and the conditioning procedure (including use of isopropyl alcohol vapour) for a nominal 610 mm × 610 mm (24" × 24") test face area. It applies to general-ventilation filters with ePM1 ≤ 99% and ePM10 > 20% (when tested per ISO 16890 procedures) and excludes filters used in portable room‑air cleaners.

Key Topics and Requirements

• Purpose: Determine the minimum (conditioned) fractional efficiency and reveal dependence on electrostatic removal mechanisms.
• Test device and cabinet: Requirements and dimensional guidance for the test device and the conditioning cabinet are provided to ensure reproducible conditioning.
• Conditioning procedure: A controlled process (commonly using IPA - isopropyl alcohol - vapour) to neutralize or reduce electrostatic charge and then re-test fractional efficiency per ISO 16890-2.
• Scope limits: Designed for filters within stated ePM ranges and for a specified nominal face area (610×610 mm); lower ePM10 < 20% filters are excluded due to statistical validity concerns.
• Safety and materials: Specifies handling considerations for conditioning materials (IPA), references MSDS and health/safety recommendations.
• Test control and reporting: Defines repeat testing, qualification, and reporting requirements so conditioned and unconditioned efficiencies can be compared and averaged where required by the ISO 16890 series.

Practical Applications and Users

Who uses ISO 16890-4:2022:

• Filter manufacturers - to characterize how much initial efficiency depends on electrostatic charge and to support product datasheets.
• Independent test laboratories - to perform standardized conditioning and efficiency verification.
• HVAC designers and facility managers - to compare filter types based on more conservative (conditioned) performance for indoor air quality planning.
• Procurement and certification bodies - to ensure consistent, comparable filter performance claims.

Practical value:

• Reveals reduction in performance after electrostatic discharge, helping select filters that maintain efficiency in service.
• Enables fair comparisons across filters by providing a standardized minimum-efficiency measurement.
• Supports better-informed decisions for building ventilation, health-sensitive environments, and regulatory compliance.

Related Standards

• ISO 16890-1 - General principles and classification
• ISO 16890-2 - Measurement of fractional efficiency (used for pre- and post-conditioning tests)
• ISO 16890-3 - Test dust capacity and initial arrestance
• ISO 29461 - Related test methods where electrostatic mechanisms are relevant

Keywords: ISO 16890-4:2022, conditioning method, minimum fractional test efficiency, air filters, ePM, IPA vapour, electrostatic discharge, general ventilation.