Duct Leakage Information
If the Digital TrueFlow® Grid is reading low air flow (cfm), and no other diagnostic causes are found, a potential cause is duct leakage between the Digital TrueFlow Grid location and the equipment blower.
The following action items listed below should be considered:
1 Move TrueFlow Grid to the cabinet filter slot
If filter grille workflow was selected, and filter slot is available, repeat test using TrueFlow Grid in filter slot.
2 Duct Leakage Screening Tool (measureQuick App)
If return ductwork is located outside of the conditioned space and there is a significant delta temperature between indoors and outdoors, this is a good opportunity for a duct leakage screening test which can be found under “Perform Quick Test” inside the measureQuick app.
3 Visual Inspection for Duct Leakage
Often duct leakage can be found visually. Inspect for duct leakage between the Digital TrueFlow Grid point of installation and the equipment blower. If duct leakage is found, seal leakage and retest system with Digital TrueFlow Grid.
4 Total Duct Leakage Test with A Minneapolis DuctBlaster®
In some cases, it is not possible to find duct leakage through visual inspection. The Minneapolis DuctBlaster is designed to measure duct leakage on a residential HVAC system. User will need to follow the process provided in the product’s quick guide, which includes sealing off registers and connecting the DuctBlaster to either pressurize or depressurize the duct system (typically 25 Pascals or 0.1 inH2O) to determine leakage rate (cfm or CFM/100 Sq Ft).
Watch Minneapolis DuctBlaster® video tutorial here:
