ISO 15957:2015

Overview

ISO 15957:2015 - Test dusts for evaluating air cleaning equipment - defines the properties and generation requirements of load test dusts used in laboratory testing of HVAC filters and air cleaning equipment. The standard specifies four designated test dust categories (L1, L2, L3, L4) by composition, particle size distribution, median diameter and density, and describes particle analysis and production methods. Note: ISO 15957 covers dusts for loading filters in performance and aging tests; it does not cover test dusts used exclusively for determining filter efficiency.

Key topics and technical requirements

• Test dust categories (L1–L4): Defined by component mixtures and reference materials.
  • L1: Mixture (Arizona desert sand ~72%, carbon ~23%, milled cotton linters ~5%) - aligns with ANSI/ASHRAE 52.2 materials.
  • L2: Arizona test dust (ISO 12103-1, A2).
  • L3: Sintered KANTO loam (narrow size distribution; detailed undersize table provided).
  • L4: Arizona sand (~93.5%) plus milled cotton linters (~6.5%) - aligns with ANSI/AHRI 680.
• Chemical composition: Mass-fraction ranges for oxides (SiO2, Al2O3, Fe2O3, etc.), carbon black and organic linters are specified per dust type.
• Particle size distribution and analysis:
  • L1, L2, L4: Arizona sand component conforms to ISO 12103-1, A2.
  • L3: Particle sizing by laser diffraction per SAP14-12 Test Powders 3 specification (undersize percentiles from ~0.89 μm to ~4.2 μm).
• Production methods:
  • L1/L4: Manufactured mixtures following ANSI/ASHRAE 52.2 or AHRI 680 procedures.
  • L2: Collected Arizona sand, jet-milled and classified.
  • L3: Sintered, jet-milled KANTO loam.
• Properties and behavior: The standard notes differences in re-suspension, pressure-drop increase and loading behavior among dust types - important for reproducible laboratory loading.
• Scope limitations: ISO 15957 specifies dust properties and generation requirements but does not regulate manufacture or field use.

Applications and users

ISO 15957:2015 is intended for:

• Test laboratories performing load and aging tests on HVAC filters and air cleaning devices.
• Filter and air cleaner manufacturers validating product durability and pressure-drop characteristics under standardized dust loading.
• HVAC engineers, facility managers and researchers estimating life-cycle cost (LCC), energy impact and aging effects.
• Standards bodies and conformity assessment organizations harmonizing test methods.

Practical uses include reproducible filter loading for durability tests, comparative lab studies of pressure-drop evolution, and inputs to LCC/LCA studies.

Related standards

• ISO 12103-1 (Arizona test dust, A2)
• ISO/TS 21220 (particulate filter performance)
• ANSI/ASHRAE Standard 52.2 (test dust and procedures)
• ANSI/AHRI 680 (test dust mixture L4 reference)
• SAP14-12 (particle sizing for L3)

Keywords: ISO 15957:2015, test dusts, HVAC filter testing, air cleaning equipment, load test dust, particle size distribution, Arizona test dust, L1 L2 L3 L4.