Overview
EN ISO 9972:2015 (ISO 9972:2015) specifies the fan pressurization method for determining the air permeability (air leakage) of buildings or parts of buildings in the field. The standard defines the use of mechanical pressurization or depressurization to measure resulting air flow rates across a range of indoor–outdoor static pressure differences. It applies primarily to single‑zone buildings (and many multi‑zone buildings treated as single‑zone by opening internal doors or equalizing adjacent zone pressures) and explicitly does not address permeability of individual building components.
Key topics and technical requirements
- Scope and applicability: Field measurement of building envelope air leakage using fan pressurization; single‑zone focus; exclusion of individual component testing.
- Apparatus: Requirements for air‑moving equipment (blower/pressurization fans), pressure‑measuring devices, air‑flow measurement systems and temperature sensors.
- Measurement procedure: Preparation of the measured extent (closing/setting HVAC, intentional openings), preliminary checks, sequence of pressure differences, zero‑flow checks and environmental condition considerations (temperature and wind).
- Data processing and results: Calculation of air leakage rates, reference values (internal volume, envelope area, net floor area), derived quantities such as air change rate at a reference pressure, specific leakage rates, effective leakage area.
- Reporting and uncertainty: Test report contents and estimation of overall measurement uncertainty, including guidance in informative annexes.
- Standards maintenance and status: Developed by ISO/TC 163 in collaboration with CEN/TC 89; this edition supersedes EN 13829:2000.
Applications and who uses it
EN ISO 9972:2015 is used by:
- Energy assessors and building inspectors for compliance with airtightness specifications and building regulations.
- Architects, façade and envelope consultants to verify design air‑tightness performance.
- HVAC engineers and retrofit contractors to evaluate the effectiveness of sealing and retrofit measures.
- Research organizations and certification bodies comparing relative air permeability across buildings or monitoring improvements.
Practical uses include: contractual airtightness verification, benchmarking building stock, measuring leakage reduction after retrofit work, and providing inputs to infiltration and heating‑load calculations (note: the method characterizes leakage-actual infiltration rates require separate estimation/calculation).
Related standards
- EN 13829:2000 - superseded by EN ISO 9972:2015.
- Prepared under ISO/TC 163 and endorsed by CEN/TC 89; national bodies adopt the standard for regulatory and compliance purposes.
Keywords: EN ISO 9972:2015, ISO 9972:2015, fan pressurization method, air permeability, building air leakage, blower door, air-tightness testing, building envelope.