Before Production
Confirm Four Items Together
Rotation and outlet angle should never be treated as isolated labels. The viewing reference, discharge position and real installation layout must be checked at the same time.
01
Viewing Side
Define the reference side first. For QIYUE FAN orders, the motor / drive-side reference should be stated explicitly on the drawing.
02
Rotation
Confirm clockwise or counterclockwise from the defined viewing side. Do not infer rotation from an unclear product photo.
03
Outlet Angle
Confirm the discharge position together with the rotation-specific drawing and the angle convention used for the project.
04
Site Layout
Check duct direction, foundation, motor position, belt cover and maintenance access.
Installation Basics
Why Rotation Direction and Outlet Angle Matter
Industrial centrifugal fans connect to ducts, dust collectors, boilers, scrubbers, furnaces and exhaust stacks. The casing outlet must face the correct direction so the fan matches the actual process layout.
01
Duct Connection
The discharge outlet must align with the downstream duct direction.
02
Motor Position
Motor, belt cover and base layout must fit the available service space.
03
Foundation Design
Anchor holes and base orientation should match the final fan arrangement.
Rotation Direction
What Is Centrifugal Fan Rotation Direction?
For QIYUE FAN orders, define the motor / drive-side viewing reference first. When viewed from that defined side, clockwise rotation is commonly described as right-hand rotation and counterclockwise rotation as left-hand rotation in Chinese centrifugal-fan practice. If the project uses another standard, keep the project convention and mark the viewing side explicitly.
Right-Hand Rotation
CW from Defined Drive / Motor Side
When viewed from the defined drive / motor side, the impeller rotates clockwise. In common Chinese centrifugal-fan terminology, this is described as right-hand rotation.
Left-Hand Rotation
CCW from Defined Drive / Motor Side
When viewed from the defined drive / motor side, the impeller rotates counterclockwise. In common Chinese centrifugal-fan terminology, this is described as left-hand rotation.
Important: "Clockwise," "counterclockwise," "left-hand" and "right-hand" are meaningful only when the viewing side is defined. Never use an unclear product photo as the final production reference.
How to Determine Fan Rotation
How to Determine Centrifugal Fan Rotation Direction
Use the same reference side for every check. The safest method is to compare the motor-side view, impeller rotation, discharge position and approved general arrangement drawing.
01
Define the Viewing Side
State motor side, drive side or another project-defined reference directly on the drawing or RFQ.
02
Identify CW or CCW
Record clockwise or counterclockwise from that side.
03
Check Discharge
Match the outlet angle with the rotation-specific layout.
04
Confirm Drawing
Approve shaft, motor, base, duct and service clearances together.
If a customer drawing uses another standard or viewing convention, keep the original standard and mark the reference direction clearly instead of converting it by assumption.
Outlet Angle & Discharge Convention
Do Not Read the Outlet Angle Without the Convention
The degree number is not enough by itself. Chinese fan-series catalogs and international project standards can use different discharge-position conventions. For a new fan or replacement project, confirm the viewing side, rotation, degree convention and physical duct direction on the same approved GA drawing.
Chinese Series / Manufacturer Catalogs
Left / Right + Model-Specific Outlet Angle
Many Chinese centrifugal-fan series identify right-hand or left-hand rotation from the motor side and list available outlet angles such as 0°, 45°, 90°, 135°, 180° and 225°. The available angles and their physical orientation must be confirmed from the drawing for that fan series.
ANSI / AMCA 99 Style
Drive-Side Rotation + Standard Discharge Names
Under ANSI/AMCA 99, rotation and angular reference are determined from the drive side. Standard examples include 360° Up Blast, 90° Top Horizontal, 180° Down Blast and 270° Bottom Horizontal, with intermediate positions also defined.
| What Is Written on RFQ / Drawing |
What QIYUE FAN Should Confirm |
Production Rule |
| Right / Left + 0° / 45° / 90° etc. |
Fan series, viewing side, physical outlet direction and available casing positions |
Use the series-specific approved drawing |
| CW / CCW + AMCA discharge designation |
Drive-side view and the exact AMCA discharge position |
Keep the project standard; do not convert by assumption |
| Photo only / angle unknown |
Reference side, shaft / motor position, outlet direction, floor orientation and duct route |
Create and approve a marked GA drawing before production |
Important for replacement projects: Never convert an existing fan from one angle convention to another using the degree number alone. Match the actual physical outlet, shaft / motor side and site duct direction first.
Model-Specific Angle Availability
Available Outlet Angles Depend on the Fan Series
Do not promise every angle for every centrifugal fan. Small direct-drive fans, large boiler fans and belt-driven process fans can have different casing and adjustment limits. Confirm the exact series and size before fixing the discharge position.
COMMON CATALOG LABELS
0° / 45° / 90°
Frequently seen in Chinese centrifugal-fan series, but availability is model-specific.
ADDITIONAL POSITIONS
135° / 180° / 225°
Common on many industrial series; confirm the casing and size before ordering.
AMCA PROJECTS
270° / 315° / 360°
May appear in ANSI/AMCA discharge designations. Keep the specified project convention.
Common Mistakes
Common Mistakes Before Ordering
Only Confirming Model
The same fan model may use different rotation and outlet arrangements.
Unclear Viewing Direction
Left-hand and right-hand rotation must use the same defined reference side.
Ignoring Service Space
Motor, bearing, belt cover and access doors need sufficient clearance.
Not Checking Duct Layout
Outlet angle should match the real downstream duct direction at site.
Replacement Fan Confirmation
What to Photograph and Mark for a Replacement Fan
For an existing fan replacement, photos are useful only when the reference direction is clear. Combine photos with the nameplate, GA drawing or key dimensions whenever possible.
01
Drive / Motor-Side Photo
Take one square-on photo showing the casing, shaft / motor or pulley side and floor orientation.
02
Outlet + Duct Photo
Show where the outlet connects, including elbow direction, duct rise / drop and nearby obstructions.
03
Mark Rotation + Viewing Side
Add an arrow for impeller rotation and write the side from which CW / CCW is being judged.
04
Send Nameplate + GA Dimensions
Include model, speed, motor data, inlet / outlet size, shaft height, base holes and any existing general arrangement drawing.
Buyer Checklist
What Buyers Should Confirm with QIYUE FAN
For a new fan or replacement project, send the rotation information and installation data together.
Fan & Rotation
• Fan model or required airflow and pressure
• Rotation direction: CW / CCW or left-hand / right-hand
• Exact viewing side used for rotation judgment
• Outlet angle plus physical discharge direction
• Angle convention or customer standard, if specified
• Motor / pulley position and drive arrangement
Installation & Electrical
• Site duct layout or installation sketch
• Base and foundation orientation
• Inlet / outlet size and maintenance clearance
• Existing nameplate / GA drawing for replacement
• Fan quantity, voltage and frequency
• Operating temperature
Frequently Asked Questions
FAQ About Fan Rotation Direction and Outlet Angle
Is centrifugal fan rotation direction important?
Yes. The rotation must match the impeller, casing and specified discharge arrangement. An incorrect direction can prevent the fan from operating as designed.
How do I confirm clockwise or counterclockwise rotation?
Define the viewing side first. For QIYUE FAN orders this should be marked as motor side, drive side or another project-defined reference. Then record CW / CCW from that side on the approved production drawing.
What is the difference between left-hand and right-hand rotation?
In common Chinese centrifugal-fan terminology, clockwise from the defined motor / drive-side reference is described as right-hand rotation, while counterclockwise is left-hand rotation. If a project uses another convention, keep the project standard.
Can the outlet angle be customized?
Many centrifugal fan models can use different outlet positions, but the available angles depend on the fan series, size, rotation, drive arrangement and casing structure. The final position should be shown on the approved GA drawing.
Can I confirm the outlet angle after production?
It is not recommended. The outlet angle should be confirmed before production because a later change may require casing, base or duct modifications.
What should I send if I am not sure?
Send the fan model or duty point, a clearly defined viewing-side photo, rotation arrow if known, physical outlet direction, duct layout, motor / pulley position, nameplate and any existing GA drawing.
