Retrotec Commercial 441 and 451 DucTester - Manual (Page 45)

Page 45 of 56
©Retrotec Inc. 2015
Step 6 – Measure Leakage Factor in CFM/100 sq ft
□ [Set Speed] to 1% then
Jog up to the Test
Pressure.
WARNING: To prevent over-pressurizing, slowly increase fan speed
using Set Speed. Jog the speed up 1% at a time until a CFM value
appears on the display. Continue to increase fan speed up to but do
not exceed the Pressure Class. If you do not reach the Pressure
Class, results will still be calculated at for that Pressure Class.
□ Tap “@” on the display
and “CFM/100 sq ft @
2.0000” will appear
Measure the Leakage Factor, F by tapping “@” on the display and
CFM/100 square foot @ the Pressure Class will appear. In our
example we set the Default pressure to 2 in WC.
□ Leakage Factor is
displayed
□ Passes if value is lower
than that specified
The Leakage Factor, F is displayed as:
If this Leakage Factor is lower than or equal to the value specified,
the duct is in compliance. If it fails, measure Leakage Class per
section below.
Step 7 – Test Passes
Complete test reports Complete test reports and, if required, obtain witness’s signature.
Remove temporary seals. Remove temporary blanks and seals.
If ducts fail, measure the Leakage Class
This is an option if you fail the test or the specification calls for this result.
Look up the Leakage Class
If this Leakage Class calculated is lower than or equal to the value
specified, the duct is in compliance. See Figure 19 Leakage Class
lookup table.
If it fails, additional sealing is
needed.