Retrotec DucTester 341 - Manual (Page 42)

Page 42 of 83
©Retrotec Inc. 2014
8.4 Combined Total Duct Leakage and Duct Leakage to Outdoors
Method
This combined method measures both Total Duct Leakage and Duct Leakage to the Outdoors with 2 fans
and 2 gauges by setting the duct to house pressure to 0 Pa using the Blower Door gauge. This method is
good for repeat testing because both measurements can be made with no changes to the gauge or the
tubing between tests. Another advantage is that the @ Pressure function can still be used. Because you
pressurize the house first, there will not be the usual problem with blowing seals off registers when the
ducts are pressurized. If your standard requires 50 Pa, substitute 50 for 25.
1. Close all exterior doors and windows and shut off exhaust fans.
2. Connect the Blower Door and DucTester as shown in Figure 37.
3. To measure Total Duct Leakage
4. Press [Set Pressure] [25] [Set] on the DucTester gauge.
5. Press [@] to display the duct leakage result "@25Pa" on the DucTester gauge.
6. To measure Duct Leakage to Outdoors,
7. Turn off “@25Pa” on the Blower Door gauge by pressing [@].
8. Set the Blower Door gauge to 0 Pa by pressing [Set Pressure] [0] [Set] on the Blower Door gauge.
9. When 0 Pa +/– 1 is achieved on the Blower Door gauge, record the result from “Flow” on the
DucTester gauge which is Duct Leakage to Outdoors.
Figure 37: Combined Total Duct Leakage and Duct Leakage to Outdoors Method, under pressurization
8.5 If no Results are displayed (--)