Overview
EN ISO 16000-26:2012 - "Indoor air - Part 26: Sampling strategy for carbon dioxide (CO2)" (ISO 16000-26:2012) is a CEN-adopted part of the ISO 16000 series that specifies how to plan and document CO2 sampling and measurement strategies in indoor environments. The standard emphasizes careful measurement planning because sampling strategy directly affects the validity of results and any decisions on remedial action. Note: this part is not applicable to carbon monoxide (CO).
Key topics and technical requirements
- Measurement planning: define objectives, boundary conditions and decision criteria before sampling.
- Properties and occurrence of CO2: background on CO2 sources (occupant metabolism, combustion) and typical ambient levels (around 300 ppm) as context for indoor measurements.
- Measurement technique: guidance on selecting appropriate measuring devices and continuous vs. spot sampling approaches (see Annex C for examples).
- When and where to measure: criteria for choosing measurement locations, timing and representative sampling periods for occupied and unoccupied conditions.
- Measurement period and frequency: considerations for short-term screening versus longer-term monitoring to characterise ventilation and occupant exposure.
- Measurement uncertainty & reporting: requirements for estimating uncertainty and presenting results that are defensible for decision-making.
- Quality assurance: calibration, instrument checks and procedural controls to avoid misrepresentation or erroneous conclusions.
- Test report content: mandatory elements to document planning, methods, results and interpretations.
- Annexes: practical annexes include calculation of ventilation requirement (Annex A), relevant regulations (Annex B) and examples of instruments/techniques (Annex C).
Applications and who uses it
EN ISO 16000-26:2012 is used by professionals involved in indoor air quality (IAQ) assessment and ventilation evaluation:
- Environmental consultants and indoor air quality specialists
- HVAC and building services engineers assessing ventilation performance
- Facility managers and building owners evaluating occupant comfort and compliance
- Occupational health & safety officers in offices, schools, hospitals and public buildings
- Laboratory and field teams designing CO2 monitoring campaigns and validating remedial actions
Typical applications include diagnosing inadequate ventilation, validating ventilation upgrades, screening occupant exposure, and supporting IAQ compliance or certification projects.
Related standards
- ISO 16000-1 (general sampling strategy for indoor air) - closely linked and presupposed by Part 26.
- Other ISO 16000 parts covering VOCs, formaldehyde, NO2 and mould sampling strategies - useful for multi-pollutant IAQ programs.
Keywords: EN ISO 16000-26:2012, indoor air, CO2 sampling strategy, carbon dioxide monitoring, ventilation assessment, air quality monitoring, measurement uncertainty, quality assurance.