Retrotec DucTester 341 - Manual (Page 37)

Page 37 of 83
©Retrotec Inc. 2014
Figure 26: Total Duct Leakage under pressurization - DucTester and tubing setup.
8.2 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”.
8.2.1. 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.
8. Complete the previous Total Duct
Leakage test.
9. Ensure all doors and windows are closed
and exhaust fans are still off (except any
doors/windows required to vent the
unconditioned space).
10. Connect the Blower Door as displayed in
Figure 28 (depressurization) or Figure 29
(pressurization).
11. 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).
12. Set the DucTester to 25 Pa (or -25 Pa) by pressing [Set Pressure] [25] [Set] on the DucTester
gauge.
13. Repeat step 5 on the Blower Door gauge.
Figure 27: Connecting the red tubes of 2 gauges
together with a T-connector