Return Air & Ductwork Installation - Friedrich VERT-I-PAK VHA09K Installation & Operation Manual

Indoor Return Air Grille and Ductwork Installation
VPRG4/R Return Air Grille with Access Panel
A field-supplied (25" x 20") can be mounted inside
the hinged access door. The door can be installed
with the grille oriented at the top of the panel for
improved sound attenuation.
Note: All Vert-I-Pak units are shipped with a 20" x 14" filter installed. If a different filter holder or location is to be used, the
filter on the chassis MUST be removed.
Ductwork
The supply duct system should be designed using a recognized method such as the equal fraction or velocity reduction method,
using the appropriate duct calculator(s) for the type(s) of duct being used in the system. The duct system should be designed
for a maximum friction rate of 0.3" with the VHA09 & VHA12, and 0.4" with the VHA18 & VHA24 water column taking into con-
sideration all fittings, registers and/or diffusers.
Note: Do not operate the unit without a supply duct attached. The return air to the Vert-I-Pak unit MUST NOT be ducted and all
units must have a free return air configuration to perform properly.
Note: For retrofit jobs, additional clearance may be required for the field supplied 10" round to rectangule transition duct for
VHA09, VHA12 and VHA18.
Option 1 Option 2
Field Supplied Return Air Grille
A field supplied return air grille divorced from the
access panel must have a minimum 250 square
inches of free area.
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