Brochure

7
How to find the damper torque
Torque Requirements
Opposed Blade Dampers with Parallel Blade Dampers with
No Seals Low Leakage Seals No Seals Low Leakage Seals
Maximum Pressures of 2 in. wg or
Maximum Velocities of 1500 fpm
3 in-lb/ft
2
5 in-lb/ft
2
4 in-lb/ft
2
7 in-lb/ft
2
Maximum Pressures of 3 in. wg or
Maximum Velocities of 2500 fpm
4.5 in-lb/ft
2
7.5 in-lb/ft
2
6 in-lb/ft
2
10.5 in-lb/ft
2
Maximum Pressures of 4 in. wg or
Maximum Velocities of 3000 fpm
6 in-lb/ft
2
10 in-lb/ft
2
8 in-lb/ft
2
14 in-lb/ft
2
Torque Formula:
Damper Area (Ft
2
) =
36 (In)
*
36 (in)
=
1,296 (In
2
)
= 9 Ft
2
Torque Factor
( )
= 10.5
( )
Required Torque (LbIn) = Damper Area (Ft
2
)
*
Torque Factor
*
Torque Factor
( )
9
*
10.5 = 94.5 LbIn
Lbln
Ft
2
Lbln
Ft
2
Lbln
Ft
2
In
2
Ft
2
144
( )
In
2
Ft
2
144
( )
Step 1:
Go to the manufacturer’s website and search the damper
part number. In some cases, a QR code will be located on the
damper itself. Scan the QR code with your phone's camera
and it will direct you to the specific damper's sections.
Step 2:
Once you’re on the manufacturer’s website, find the
Torque Requirement Table containing the torque factor
information needed.
Step 3:
Using your check list of information and the chart provided,
you find that the torque factor is 10.5 in-lb./ft squared. Now,
multiply that torque factor by square feet, check all the units
and find the torque that is needed for this application which
is just under 94.5 lb.-in.
Torque Vector Table
Torque Factor (Lb. In/Ft²)
Air Velocity (Ft/Min) < 1200 < 2500 < 3000
Damper Blade Style
Opposed Blade No Seals 3 4.5 6
Opposed Blade with Seals 6 7.5 10
Parallel Blade No Seals 4 6 8
Parallel Blade with Seals 8.5 10.5 14
EXAMPLE:
To find the required torque for an outside air damper, inspect the damper. In this example, it has a manufacturer label
on it with product specifications that provides all the critical information needed on your check list.