When a duct system is placed under negative pressure for cleaning, return air leakage and supply air leakage are no longer governed by the same pressure conditions they experience during normal HVAC operation. That distinction is the key to diagnosing extraction...
When a duct-cleaning vacuum is running but debris is not moving effectively through the section being cleaned, the problem is not necessarily the vacuum itself. In many cases, the more useful question is where the vacuum is connected and what airflow path that...
The duct vacuum hose diameter can materially affect how much airflow resistance develops between a professional vacuum and the section of duct being cleaned. But diameter is only one part of the equation. A larger hose provides more cross-sectional area and, under...
A duct access opening should do more than create a way into the duct. It should provide enough working access for cleaning or inspection while preserving the duct’s physical condition, airflow function, insulation, and ability to be properly closed afterward....
