Pulse is a portable compressed air based system which is used to measure the air leakage of a building or enclosure at a near-ambient pressure level (4Pa).
A concept originally pioneered by the University of Nottingham, the system releases a small burst of air which generates a flow rate through the gaps and cracks in the building. The change of internal pressure of the building due to this flow is seen as a ‘pulse’ and its representation is characteristic of the building’s leakage.
Pulse dynamically measures building air leakage directly at low pressure. Crucially, this provides an air change rate measurement that is representative of normal inhabited conditions, helping to improve understanding of energy performance and true building ventilation needs.
Further advantages of taking measurements in a dynamic way is that the duration of the measurement phase of the test can be implemented in a matter of seconds. It also makes the test less susceptible to wind disruption, especially as no external pressure tappings or envelope penetrations are required for the test to run.
The test itself takes less than 20 seconds for 3 air releases, with charging of the vessel between tests taking approximately 10 minutes depending on the compressor used. At the same time, the tester can measure the building dimensions, prepare the building and ensure the correct system set-up.
Occupants may remain in the building for the duration of the testing but may not open doors or windows. The test does not penetrate the envelope and will not change the temperature of the building.
Simple to operate
The Pulse unit is simply wheeled and placed into the centre of a building and can be operated using single button operation.
Accurate and repeatable
The Pulse test is able to provide highly repeatable results at low pressures found in infiltration whilst the system also minimises the impact of changes in background pressure due to wind and buoyancy.
The test process causes no change to the building fabric during testing and does not force leakage paths which would not otherwise be there in a typical as-inhabited state.
Large building tests
Multiple standard Pulse test units can be linked and used simultaneously in large buildings to achieve the required pressure rise with a uniform pressure distribution.