When you build a duct system, if you want it to work correctly you run a tightness test. See how Corbett did on his home’s first of 5 duct systems for different purposes. Using a Retrotec Duc Tester 300 with DM-32 manometer, available at: https://trutechtools.com
Watch the whole episode, and the whole season: https://HomeDiagnosis.tv