Greenheck On-site testing and Adjusting Pressure Relief Doors (469133) User Manual
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The design elements of your particular HVAC installation may create velocity pressures that will affect the
operation of this Pressure Relief Door. These elements include:
• size, speed, and design of the fan
• proximity of the pressure relief door to the fan or damper
• configuration of the ductwork
• airflow dynamics at the location of the pressure relief door
Because of these variables, it is imperative that this door be tested in place, and the latch adjusted as
needed.
To adjust the pressure setting of the magnetic latch to a higher pressure, loosen the set screw and move the
latch away from the hinges. Conversely, to adjust the pressure setting of the latch to a lower pressure, move it
closer to the hinges.
In some cases, it may be necessary to remove the slotted latch-mounting bracket, reverse it end-for-end, and
re-mount it onto the door frame in order to extend the range of the adjustable magnet.
Although the magnet is sized for a predetermined pressure range, the door is usable outside of this range
by replacing the magnet with one having more or fewer magnetic bars. If such a magnet is needed for your
application, contact A.J. Manufacturing.
The box below shows the approximate relationship between latch distance and air pressure for different door
sizes:
Document Number 469133
Installation Instructions for On-Site Testing
and Adjustment of Pressure Relief Door
Door Size (in inches) Magnet size
Distance to equal
approximately 1 inch wg
10 x 10
1-bar
1/2 inch
10 x 10
2-bar
3/8 inch
12 x 12
1-bar
1/2 inch
12 x 12
3-bar
1/4 inch
18 x 18
5-bar
3/8 inch
18 x 18
10-bar
3/16 inch
24 x 24
5-bar
1/2 inch
24 x 24
10-bar
1/4 inch
®
469133• PRAD VRAD Adj. Rev. 2, October 2012
Copyright 2012 © Greenheck Fan Corporation
As a result of our commitment to continuous improvement, Greenheck reserves the right to change
specifications without notice.
Specific Greenheck product warranties are located on greenheck.com within the product area tabs and in
the Library under Warranties.
®
Phone: (715) 359-6171 • Fax: (715) 355-2399 • E-mail: [email protected] • Website: www.greenheck.com
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