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Chapter 9
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.
• 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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