Troubleshooting center
Testing & Diagnosis
What is actually measured, how duct leakage testing works, and what the numbers mean.
Each guide answers the question first, then explains the likely causes in order — duct leakage only where the evidence actually supports it, and a licensed HVAC contractor where it doesn’t.
3 guides in this category
How Is Duct Leakage Tested?
The equipment and steps behind a duct pressurisation test, and what each reading measures.
Read the answerWhat Is a Duct Leakage Test?
What the test actually measures, how it differs from a general inspection, and what it does not tell you.
Read the answerWhat a Duct Leakage Number Means
How to read a CFM25 result — relative to what, judged against what, and what it can't tell you alone.
Read the answer
Find out what your duct system is actually doing.
Schedule a duct leakage evaluation and get measured numbers for your home — not a guess.