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Chapter 8
INSTALLATION: Diffusion via HVAC System
Injector Tube Installation
The injector tube is installed directly into the AHU or ductwork. Its orientation can be adjusted relative to
airflow.
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For installations into the negative/suction side of the AHU fan, orient the tube with the elbow pointed
upwards, so that any plume condensation will drip back down the tube.
•
For installations after the supply fan, such as in a supply duct, it is necessary to configure and orient
the Injector Tube to obtain a good aspiration of the output into the air stream. The injector tube
should be pointed in the direction of the airflow and inclined approximately 45o upward. Turbulence
in the airflow can prevent even aspiration of the plume. It is best to place the tube in a straight
section of duct, and far away from any turns, branches, or cross-section changes as practical, and not
immediately after the supply fan.
1. At the insertion point, drill a hole using a ½” drill bit.
2. Insert the Injector Tube through the hole.
3. Find an orientation of the injector Tube that appears to produce a good draw of air into the end of the
barb.
4. Fasten the flange using the three #10 sheet metal screws.
5. Turn the appliance on and verify that a plume is produced.
6. Before attaching the Injector hose to the injector, verify that the plume can flow easily through the
injector. This can be done by placing the end of the hose ½ inch away from the injector and verifying
that the plume is being drawn in (a flashlight will make the plume easier to see). If the plume does not
rise into the hose, adjust the orientation of the Injector Tube until aspiration is achieved.
7. Attach the Injector hose onto the hose barb of the Injector Tube.
For Cartridge Installation – See “
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