Selecting a fan for an industrial ventilation system requires more than just selecting a fan type. Other characteristics such as airflow, operating temperature, drive placement and mounting, and those listed below should also be considered.
Common Industrial Ventilation Vent Fan Types
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Axial Fan
In an axial fan, the blades extend radially outward and the air is also repositioned parallel to the command of the fan impeller's axis of rotation. With the help of the vanes, the air is rotated from the circumference of the main indication. Air pressure is created aerodynamically when the fan blades are pushed out. DC axial fans are more suitable for low pressure applications due to their compact design. They are suitable for minor exhaust applications with volumes of air, dirt or smoke.
Industrial ventilation axial flow fan application:
- Air Conditioning and Refrigeration
- Fresh Air Supply and Airflow
- exhaust
- Unidirectional Airflow Applications
- Important considerations when selecting an application-focused industrial ventilation fan
Below are some standard aspects to consider when selecting or purchasing a fan for a specific industrial ventilation application.
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Centrifugal fan
These fans blow air or gas using centrifugal force and have rotating impellers. They have a rotating disk that creates centrifugal force by rotating the blades. They have wheels that capture the air and blades that push it according to the best instructions. Once the wheels trap air inside the manor, it is expelled by the blades at a 90 degree angle and out of the housing. The impeller squeezes air radially outward, then tangentially away from the blades. The blown air velocity is close to the tail velocity, causing a pressure rise. Therefore, these fans are suitable for high voltage applications. They are ruggedly designed to withstand extreme commercial environments, polluted air, humidity, and more.
Depending on the application, there are 2 most typical types of centrifugal blowers:
Pressure Fans: These are used to expel air under high pressure.
Positive displacement fans: These fans push and expel large volumes of air at reduced constant pressure.
Industrial Ventilation Fan Applications
Centrifugal blowers have different applications in different industries. Here are some applications of industrial ventilation blowers:
- network web server
- telecommunications system
- dirt collection mechanism
- Exhaust and Air Conditioning
- Filtration and Suction
Considerations when choosing a fan
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Capacity
Flow rate: The flow rate depends on the system requirements. Flow should be specified as ACFM or SCFM. Air temperature, fan height, humidity, and other air density factors need to be provided to the fan manufacturer.
Pressure Requirements: Fan Static Pressure (SP) or Fan Total Pressure (TP) based on system pressure requirements. A system pressure drop calculation should be done to determine SP and TP values.
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Airflow
Materials Handled: Particulate or moisture in the airflow requires careful selection of the proper fan impeller or blades, depending on the material being conveyed. Buildup or corrosion on fan impellers can lead to safety concerns, reduced performance and bearing failure due to imbalance.
Explosive or Flammable Materials: Always refer to National Fire Protection Association standards and other government regulations when handling explosive or flammable materials. If there is a risk of explosion or flammability, non-sparking wheel materials and special bearings and controls should be considered.
Corrosive applications: If used in corrosive applications, protective coatings or special materials such as stainless steel, fiberglass or plastic may be required.
Increased Airflow Temperature: The maximum airflow temperature needs to be known as temperature affects the strength of the fan material.
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Installation restrictions
- Inlet size and location
- Outlet size and location
- Fan Arrangement/Orientation
- Fan weight
- Easy fan maintenance
- available physical space
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Drive
Power supply: All industrial ventilation fans require a power supply. If an electric motor is used, a variable frequency drive (VFD) can be used to control the fan speed.
Direct Drive: Direct drive ensures consistent fan speeds while providing more compact components.
Belt Drive: The gear ratio allows the speed of the fan to be adjusted. If modifications are made to processes, hood design, equipment location, or air cleaning equipment, system capacity or pressure requirements may need to be changed. With belt driven fans, the motor can be located in various locations/arrangements.
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Noise
Noise: All fans produce "noise".
Sound Power and Sound Pressure: Noise levels are measured in units called decibels (db). Noise levels will vary depending on speed, interconnecting ductwork and point of operation. Sound pressure is a measurement affected by fan position and other environmental factors.
Noise Contributors:
The type of fan, flow rate, pressure, and fan efficiency all affect the noise produced by the fan.
The quietest fans are usually those with backward facing impeller designs.
Fan noise levels can increase with any type of fan if there is uneven airflow at the fan outlet or inlet.
A silencer or sound enclosure can be added to the fan to reduce noise.
To meet some of today's tough requirements, adding a silencer isn't enough. Many fan manufacturers now offer fans with integrated silencers. This virtually eliminates the noise transmitted through the fan housing. Another advantage of this design is that the silencer fan will be shorter and easier to handle than a standard fan with two silencers.
Also, fan speed can affect noise levels. If excessive noise is an issue, choose the lowest speed fan that meets the desired performance.
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Safety and Accessories
Guarding: In order to comply with government security requirements, guarding must be included. Hazard points to consider include inlets, outlets, shafts, drives, belts and cleanout doors.
Accessories: Accessories such as drain pipes, cleanout doors, split housings, inlet boxes and shaft seals are available to aid in the installation and maintenance of industrial ventilation dust collection systems.
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Flow control
Flow Rate: Proper control of flow rate provides several benefits, including reduced energy requirements.
Fan Accessories: Dampers, Variable Pitch Vanes, and Velocity Control (VFD) are the three main fan accessories that help manage flow rates in industrial ventilation systems.
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Motor selection
An important aspect is choosing a fan with a suitable motor. Does the application require Explosion Proof (XP) equipment? Or are there other mandatory requirements? If so, the fan must comply with local regulations, including covering and gas conditions or possible combustible dust. This can cause another problem if the fan will be running with a variable frequency drive (VFD). Many motor companies offer XP motors that are not UL rated to operate with a VFD.
Another potential pitfall about electric motors is the availability of replacement motors in the event of a catastrophic failure. Some manufacturers use non-standard mounts and shaft designs that require highly modified or special order replacement motors, resulting in long lead times.
Conclusion
If you are looking for a suitable ventilation fan to fit your ventilation system, or to start your business, please contact us for our latest product consultation, and our engineers will be eager to give you any help.
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