Overview
SIST EN ISO 12569:2018 (ISO 12569:2017) specifies accepted methods to determine the specific airflow rate (ventilation rate) in a building space using the tracer gas dilution method. It applies to single‑zone spaces where conditions for tracer gas uniformity, exhaust concentration measurement, an effective mixed zone and limited ventilation fluctuation are met. The standard is published by ISO and adopted as a European standard (EN ISO 12569:2017) and as SIST EN ISO 12569:2018.
Key topics and technical requirements
- Measurement methods: ISO 12569 defines three tracer gas techniques:
- Concentration decay method (two‑point, multi‑point, step‑down exhaust, pulse variants)
- Continuous dose method (average inverse concentration, average concentration, stationary concentration)
- Constant concentration method
- Applicability conditions: Measurements are valid when tracer concentration uniformity, effective mixed zone behavior and controlled ventilation fluctuations are satisfied (see standard and its Table 1 for specific conditions).
- Instrumentation and sampling:
- Tracer gas dosing devices, sampling systems and gas analysers are covered.
- Requirements on analyser resolution, drift, accuracy and calibration are included.
- Procedures and calculations:
- Step‑by‑step procedures for each method and associated calculations.
- Guidance on ancillary measurements (temperature, outdoor conditions, HVAC schedule).
- Accuracy and uncertainty:
- Statements on measurement accuracy, calibration, tracer dosing and sampling effects.
- Normative annexes provide confidence intervals, simultaneous estimation of ventilation rate Q and effective mixed zone volume V_emz (Annex B), and error propagation methods.
- Informative annexes: Practical considerations for large spaces, temperature effects and strategies to minimize estimation error.
Practical applications and users
ISO 12569 is used where reliable quantification of ventilation or specific airflow rate is required:
- Building energy performance assessments and thermal performance testing
- HVAC commissioning and ventilation system verification
- Indoor air quality investigations and contaminant dilution studies
- Airtightness and building envelope diagnostics (complementary to airflow pressurization methods)
- Research laboratories and field testing services
Typical users:
- HVAC engineers, energy assessors and commissioning agents
- Test laboratories and accredited field measurement teams
- Building consultants, facilities managers and researchers
Related standards and references
- Adopted as EN ISO 12569:2017 and published nationally as SIST EN ISO 12569:2018.
- Prepared by ISO/TC 163 in collaboration with CEN/TC 89; supersedes earlier editions (EN ISO 12569:2012).
- Use alongside standards for indoor air quality, ventilation design and test‑equipment calibration for comprehensive compliance.
