PULSE – our improved system for measuring building air permeability

Author: Luke Smith 05/09/2016

Uncontrolled air leakage in buildings can account for as much as 30% of the total heat loss; an energy penalty that increases even further in premises that are cooled or continuously conditioned.

What’s more, buildings that are airtight but not adequately ventilated can present risks to the health of both the building structure and the occupants. However, despite its importance, techniques for both measuring and modelling air permeability are inaccurate and unreliable.

As building designers strive to achieve higher energy efficiency in a bid to comply with current and future, more stringent, Building Regulation targets, airtightness has become a major performance issue that cannot be ignored.

Our response was to work alongside The University of Nottingham, Elmhurst Energy, Absolute Air and Gas and others to develop a new and innovative airtightness testing system. The PULSE technique is a compressed, air­based alternative to the blower door fan method, which works by subjecting a building envelope to a known volume change and measuring the pressure response.

PULSE is fast, low skill, undisruptive and robust. It’s also highly accurate in measuring the airtightness of the building envelope under natural atmospheric conditions.

By using low pressure, it offers certain benefits over conventional tests:

  • Unobtrusive for occupants as the test is quiet and doesn’t disturb household objects.
  • Provides a more accurate measurement of fabric infiltration.
  • Reduces the time taken to set up and complete a test.
  • Carried out using a relatively small, lightweight composite pressure vessel, which is standalone and portable.

PULSE is now commercially available and has the potential to revolutionise the way air­tightness testing is undertaken. Our research shows that this new method will:

  • Dramatically improve the accuracy of how air permeability is measured.
  • Provide the opportunity for more buildings to be tested.
  • Allow for risks and improvements to be better understood.