Retrotec DucTester 200 Series Residential Applications - Manual (Page 29)

Page 29 of 91
©Retrotec Inc. 2015
While it would be ideal to seal between the register and the wall using Grill Mask, caution must be
used to prevent pulling paint off the wall.
4. Seal combustion air and ventilation inlets directly connected to the duct system. This can be done by
sealing the opening on the outside of the building, but can also be done by removing the inlet from
the duct work and taping off the opening.
5. Turn off all exhaust fans, dryers, and room conditioners.
6. Turn off vented combustion appliances, if there is a possibility that the area containing the appliance
will become depressurized during the testing procedure.
7. Open all interior doors leading to rooms containing a supply or return register (and open an exterior
door or window for a Total Duct Leakage test – see section 5.1). When ducts run through an
unconditioned space, that space must
also be opened to the outdoors, to relieve any pressure that
may build up in that space during the test.
3.10 Install Range Ring on fan
Each Retrotec DucTester includes three Range Configurations to
maximize accuracy and versatility: Low, Mid, and Open. The
selected Range Configuration will determine the range of air flow
that the DucTester can measure. While it is easy to change the
Range Configuration when pressurizing, it is better to make your
best guess at the correct Range Configuration when testing in the
depressurization direction since the Flex Duct must be removed to
change Range Configurations. Do NOT try to forcefully attach the
Range Rings to the exhaust; they must always go on the inlet of
the fan, where the Velcro holds them in place.
Remove a Range Ring for leakier ducts or add a Range Ring for
tighter ducts. Testing should always be done at the highest
possible fan speed, which means using the most restrictive Range
Configuration possible (the one with the smallest hole possible).
Higher fan speeds lead to the highest degree of accuracy. If the
fan is running too slowly “TOO LOW” or “-----“ will appear on the gauge display indicating you must
change to a more restrictive range.
Generally, the “Mid” range will work for most duct systems.
Figure 27: Turn off the
air handler Figure 26: Remove
all air filters Figure 25: Seal all supply and return registers with
Grill Mask
Open
Mid
Low
Figure 28: Range Plates for the Model 200.