Centrifugal Fan Discharge describes how to position the fan outlet (what direction it should point). This is a basic and important determination for your industrial fan application, assuming you want the air that is pulled into the fan to have somewhere to go when it leaves. Specifying the correct fan discharge helps to ensure smooth fan installation and system setup.
Duct, Duct, Direction
To determine the direction of your centrifugal fan discharge, review your system’s design and the space around your fan installation site, and identify:
- Where do you want the air to go when it leaves the fan?
- What is the layout of your existing and/or planned ductwork?
- What fan rotation do you need – clockwise (CW) or counterclockwise (CCW)?
Once you have the lay of the land, you have several options for specifying your fan discharge position. Start by looking at your fan from the drive (motor) side. From there, the positions are specified by a combination of fan rotation, outlet location (top or bottom), and the outlet angled position. Here are the standard designations for the outlet location/angle:
- 360-degree Up Blast – the discharge is headed straight up
- 45-degree Top Angular Up
- 90-degree Top Horizontal
- 135-degree Top Angular Down
- 180-degree Down Blast – the fan outlet is headed straight down
- 225-degree Bottom Angular Down
- 270-degree Bottom Horizontal
- 315-degree Bottom Angular Up
Demonstration Video: Determining Centrifugal Fan Discharge Position
Senior Application Engineer Chet White recently shared how to determine centrifugal fan discharge position on AirPro’s YouTube Channel. You can watch the 1½ minute video here.
Related Content: Do You Need an Inlet Box?
While you’re looking at your ventilation system surrounding the fan application, consider the other side of the fan, or the inlet. To help determine if you need an inlet box, check out Chet’s Inlet Box Video or Read the Inlet Box Blog.