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

Contact Information Centre

This guide provides a detailed procedure for testing domestic ventilation systems. It has been updated to reflect the revised guidance for Part F of the Building Regulations, which came into effect in England and Wales in 2022.

Download a sample preview

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

Product details

  • Published: September 2022
  • Publisher: BSRIA
  • Authors: Alan Gilbert & Chris Knights
  • ISBN-13: 978-0-86022-794-6

Common customer questions & answers

QQuestion Should kitchen extract hoods be tested with the filters in place?
AAnswer Yes. This is so that the test result is representative of how the extract hood will perform in real life.
QQuestion If multiple speeds are available on a kitchen extract hood, which should be used for the test?
AAnswer The extract hood should be tested on the highest speed testing.