Domestic Ventilation Systems - a guide to measuring airflow rates (BG 46/2022)

With the improvements in dwelling airtightness over the past few years, and increased use of systems such as Mechanical Ventilation with Heat Recovery (MVHR), getting the ventilation right in dwellings has become more critical. In 2010, a requirement for mechanical ventilation air flow rate testing in dwellings was written into the England & Wales Building Regulations. A new Approved Document F Volume 1, providing guidance on meeting Building Regulations requirements for ventilation in England, was published in 2021 and came into effect on 15th June 2022. A version for use in Wales, providing the same guidance, was published in 2022 and will come into effect on 23rd November 2022. This third edition takes into account the revised guidance and also provides more detailed information about equipment calibration.

The first edition of this BSRIA guide was published in 2013, describing the conditional and unconditional methods of airflow measurement. The second edition, published in 2015, also describes a third method, the minimum benchmark method.

Contents include:

• Types of ventilation systems
• Performance requirements
• Design and installation
• Airflow measurement – conditional, unconditional and minimum benchmark methods
• Testing and commissioning
• Correct calibration of instrumentation for airflow measurement

The test work to support the methodology recommended in this guide was undertaken independently by BSRIA. Read report