Retrotec DucTester 341 - Manual (Page 25)

Page 25 of 83
©Retrotec Inc. 2014
6.4 Seal all supply registers
Preparing for a duct leakage test requires preparing both the duct system and the building. The
following setup procedures are recommended by Retrotec. If the test is being conducted according to a
specific program guideline, you may be required to set up the duct system and building differently than
what is described below.
6.4.1. Before beginning the duct leakage test
1. Adjust the HVAC system controls to ensure that the air handler does not turn on during the test.
1. Remove all filters inside the ductwork including any filter that is behind the return grill (that the
DucTester will be connected to).
2. Seal off all remaining supply and return registers using Grill Mask. A roll is provided with all
DucTester systems.
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.
3. 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.
4. Turn off all exhaust fans, dryers, and room conditioners.
5. Turn off vented combustion appliances, if there is a possibility that the area containing the appliance
will become depressurized during the testing procedure.
6. 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 8.1). 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.
Figure 12: Turn off the
air handler Figure 11: Remove
all air filters Figure 10: Seal all supply and return registers with
Grill Mask
Optional
Vent Cap
register sealing
system.
Optional
Duc-Bloc
register sealing
system.