Duct leakage testing
We pressurize sections of ductwork and measure how much air escapes, so leaks are found and sealed before the ceilings close.
When you need it
- The specification requires leakage testing of medium- or high-pressure ductwork.
- Ductwork is installed and needs testing before the ceiling or insulation goes in.
- A fan is moving its rated airflow but the rooms aren’t getting it.
- You need documentation for energy code compliance or LEED.
What we do
Plan the test sections
We work with you to divide the ductwork into testable sections and agree on the test pressure and allowable leakage for each.
Seal and pressurize
We cap the openings of each section and pressurize it with a calibrated test rig.
Measure and locate
We measure leakage at the test pressure and, if a section fails, help find the leaks so they can be sealed.
Retest and report
Failed sections are retested after repair, and every result is documented section by section.
What you receive
- Leakage measured for each section, with test pressure and duct surface area
- Pass or fail against the allowable leakage
- Retest results for any sections that were repaired
- Marked-up drawings showing what was tested
Questions
Why test before the ceiling closes?
Leaks are cheap to seal while the ductwork is exposed. Once the ceiling is in, finding and fixing them costs far more.
How much leakage is allowed?
It depends on the duct pressure class and the specification. The engineer sets an allowable rate, usually based on SMACNA leakage classes, and we test against it.
Do you test ductwork in houses?
Yes. Leaky ducts in unheated spaces are a common cause of cold rooms and high heating bills in homes.
Further reading
- Duct design methods: equal friction, static regain and more
A practical comparison of the main duct sizing methods used in commercial HVAC, with typical design values and guidance on choosing the right method for a project.
- Duct sealing classes and SMACNA leakage standards
Understand SMACNA duct seal classes and leakage classes, how allowable leakage is calculated, and how to specify and verify duct sealing on commercial projects.
- Air balancing procedures and instruments
Learn the instruments used to measure airflow and pressure, and the step-by-step procedure for balancing constant volume and VAV air systems.
- Duct leakage testing procedures
Learn how ductwork is pressure tested for leakage, how allowable leakage is calculated from SMACNA leakage classes, and how to plan testing so it does not delay construction.
Related services
Also in testing, adjusting and balancing: Air balancing (TAB), Water balancing (hydronic), Control system verification, Residential air balancing.
Get a quote for duct leakage testing
Tell us about the building and what you need. We’ll be in touch within one hour.