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33.
Close all doors and windows and shut off any
exhaust fans in the building.
34.
Keep the blue port on the gauge open to the
house, run the red tube from the gauge to the
outdoors, and run the yellow and green tubes
to the DucTester. Manually adjust the Blower
Door speed (with the Speed Control Knob on
the Blower Door fan) to change the building
pressure until 25 Pa appears for Duct Pressure
(Channel A) of the gauge.
35.
Connect the blue tube from the duct register to the gauge.
36.
Manually adjust the DucTester speed (with the Speed
Control Knob on the DucTester) to reach 25 Pa in the ducts. Wait 60 seconds.
37.
With the DucTester still running, disconnect the blue tube from the gauge and re-adjust the Blower
Door speed to again set the building pressure to 25 Pa.
38.
Connect the blue tube to the gauge and re-adjust the DucTester fan speed to achieve 25 Pa.
39.
Record duct leakage, “Flow” on the gauge, when you’re confident the building and duct pressures
have both been stabilized at 25Pa.
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 t
he 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 o
n the Blower Door gauge, record the result from “Flow” on the
DucTester gauge which is Duct Leakage to Outdoors.
Figure 36: 1 Gauge Duct Leakage to Outdoors under
pressurization, setting the duct pressure
Summary of Contents for DucTester 300
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