Installation - Greenheck DFD Series Installation, Operation And Maintenance Manual

Installation

Installations with poor inlet or discharge configurations
may result in reduced fan performance.
Ducted Installations
Inlet Duct Turns – Installation of a duct turn or elbow
too close to the fan inlet reduces fan performance.
Restricted or unstable flow at the fan inlet can cause
pre-rotation of incoming air or uneven loading of the
fan wheel, yielding large system losses and increased
sound levels. To achieve full fan performance, there
should be at least one fan wheel diameter between the
turn or elbow and the fan inlet.
Good
1 Fan
Wheel
Dia.
Turning
Vanes
Discharge Duct Turns – Fan performance is reduced
when duct turns are made immediately off the fan
discharge. To achieve cataloged fan performance there
should be at least three equivalent duct diameters of
straight ductwork between the fan discharge and any
duct turns.
Poor
Non-Ducted Installation
Inlet Clearance
Installation of a fan with an open inlet too close to a
wall or bulkhead will cause
reduced fan performance.
It is desirable to have a
minimum of one fan wheel
diameter between the fan
inlet and the wall.
Free Discharge
Free or abrupt discharge
into a plenum results
in a reduction in fan
performance. The effect of
discharge static regain is not
realized, and performance is
reduced.
4 Mixed Flow
Poor
Length of
Straight Duct
Good
1 Fan
Wheel
Dia.
Duct Connections
It is highly recommended to use a flexible sleeve
connection instead of a rigid duct connection. This will
reduce vibration transmission through the ductwork.
Slip-Fit End Connection
Directly attach the flexible sleeve to the duct and fan.
No additional parts are required.
Flexible Sleeve
Fan
Flanged End Connection
Optional companion flanges are bolted to the fan to
provide a slip-fit connection for a flexible sleeve.
Flexible Sleeve
Fan
Companion Flange
Note: Flexible sleeve & attachment hardware not provided.
Duct
Duct