Installation
Installations with inlet or discharge configurations that deviate from this standard may result in reduced fan performance. Restricted or unstable flow at the fan inlet can cause
Ducted Inlet Installations
Inlet Duct Turns - Installation of a duct turn or elbow
too close to the fan inlet |
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reduces fan performance |
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because air is loaded |
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unevenly into the fan |
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wheel. To achieve full fan |
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performance, there should |
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be at least three fan wheel |
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diameter between the turn | POOR |
or elbow and the fan inlet. |
Three fan wheel diameters |
Turning |
Vanes |
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Inlet Spin - Inlet spin is a frequent cause of reduced fan performance. The change in fan performance is a function of the intensity of spin and not easily defined. The best solution is proper duct design and airflow patterns. Turning vanes reduce the effects of inlet spin.
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Ducted Outlet Installations
Discharge Duct Turns - Duct turns located near the fan discharge should always be in the direction of the fan rotation.
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fan discharge. To achieve cataloged |
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fan performance there |
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three equivalent |
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GOOD
Non-Ducted Installations
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 one fan wheel diameter between parallel fan units and a minimum of
One fan | One fan |
wheel | wheel |
diameter | diameter |
Single Fan Installation
3/4 to |
| 3/4 to |
one fan | One fan | one fan |
wheel | diameter | wheel |
diameter |
| diameter |
Parallel Fan Installation
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.
4Model