Retrotec DucTester 200 Series Residential Applications - Manual (Page 36)

Page 36 of 91
©Retrotec Inc. 2015
Figure 34: Total Duct Leakage under pressurization - DucTester and tubing setup.
5.2 Duct Leakage to Outdoors with 2 gauges and 2 fans
A Duct Leakage to Outdoors Test neutralizes the duct leakage to the house (or conditioned spaces) by
pressurizing the house to the same pressure as the ducts. The measured duct leakage thus only reflects
the leaks to outdoors.
If a green, self-referencing, pressure port is available on the Blower Door fan, use the green pressure
tube to connect it to the Blower Door gauge, and ensure the Device chosen on the gauge is “Retrotec
3000SR”.
5.2.1. Method #1: Set both duct and house to -25 Pa (or 25 Pa)
Method 1 allows the [@Pressure] extrapolation function to be used, increasing accuracy and allowing
the test to be carried out with a single setting for the DucTester and Blower Door gauge. No changes
need to be made on the DucTester gauge from the Total Duct Leakage Test, which is convenient if you
have to carry out both tests.
1. Complete the previous Total Duct Leakage test.
2. Ensure all doors and windows are closed and exhaust
fans are still off (except any doors/windows required to
vent the unconditioned space).
3. Connect the Blower Door as displayed in Figure 36
(depressurization) or Figure 37 (pressurization).
4. Connect the red ports together with one red tube, and
run the end outdoors as shown in Figure 36. This makes
the duct and house pressure measurements use the
same reference (outdoors).
5. Set the DucTester to 25 Pa (or -25 Pa) by pressing [Set
Pressure] [25] [Enter] on the DucTester gauge.
6. Repeat step 5 on the Blower Door gauge.
Figure 35: Connecting the red tubes of 2 gauges
together with a T-connector