Retrotec DucTester 200 Series Residential Applications - Manual (Page 41)

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©Retrotec Inc. 2015
5.4 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 45.
3. To measure Total Duct Leakage
4. Press [Set Pressure] [25] [Enter] on the DucTester gauge.
5. Press [@ Pressure] 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 [@ Pressure].
8. Set the Blower Door gauge to 0 Pa by pressing [Set Pressure] [0] [Enter] 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 45: Combined Total Duct Leakage and Duct Leakage to Outdoors Method, under pressurization
5.5 If no Results are displayed (TOO LOW or ---)
If the target pressure has been reached, but “TOO LOW” or “---“ appears as a flow reading, the fan is
running too slowly to measure flow. Perform the following to get a duct leakage result:
1. Add the next smaller Range Ring.
2. Change [Range Config] on the gauge to match the Range Ring installed on the fan.