High-Performance Plug Fans for HVAC Systems&Data Centers

A unique type of backward curved centrifugal fan with simple structure, high hydrostatic efficiency and small size.
Plug fan, also named plenum fan, is a kind of casingless backward curved centrifugal fan. It has no traditional casing, consisting only of a centrifugal impeller and a motor behind it. The compact structure and small volume make it can be directly “inserted” or “embedded” into the equipment box for use, such as air conditioning units, air purification equipment, etc. It’s very convenient to install and disassemble.
 
The plug fan’s streamlined design delivers multiple advantages. Its bladeless structure eliminates noise from impeller-volute friction at the source. The flexible inlet/outlet configuration accommodates diverse air conditioning unit requirements. Furthermore, this design prevents belt wear and tear, significantly extending service life.

Features of Plug Fan

Saving Space

Saving Space

Unlike traditional centrifugal fans and chassis fans, the plug fan’s compact design allows it to be directly integrated into the system’s static pressure box, saving up to 26% of space.
High Efficiency

High Efficiency

The plug fan adopts reverse impeller, which reduces the resistance of air flow, improves the energy conversion efficiency, and enables the fan to achieve high static pressure efficiency.
High Adaptability

High Adaptability

Plug fan can be equipped with insulation plates and shaft seals, which can not only be used in clean air-conditioning boxes, but also adapt to high temperature or polluted environments.
Easy Maintenance

Easy Maintenance

When the plug fan needs maintenance, you can quickly pull out the entire fan module from the equipment housing without having to remove large amounts of piping or equipment around it.
Low-noise Operation

Low-noise Operation

The plug fan removes volute, eliminating this major source of noise at its root. Moreover, its backward-flow impeller allows for more stable and uniform airflow, reducing aerodynamic noise.
Energy Conservation

Energy Conservation

The plug fan is generally connected directly to the motor, which greatly eliminates the energy loss of the belt and maintenance costs. The average efficiency of its EC motor is more than 90%.
√ Wheel Diameters: 8 to 66 inches
 Airflow Capacities: 500 to 440,000 CFM
 Max. Temperature Tolerance: up to 2,200°F
 Max. Pressure Resistance: 12 inches w.g. (2,980 Pa)
 Drive Types: belt drive or direct drive
 Motor Power Ratings: 0.25 HP to over 15 HP
 Mounting Direction: horizontal or vertical
 Optional Materials: steel, aluminum, stainless steel 316, etc.
 
Note: The above data represents the conventional configuration. For more OEM requirements, please contact us immediately for exclusive customized solutions and quotations.

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Plug Fan vs Centrifugal Fan

Plug Fan vs Centrifugal Fan

Plug fan is a special type of centrifugal fan with backward-tilted blades and no volute. When choosing between plug fan and conventional centrifugal fan, you might be wondering: “Which one should I pick?” Then keep reading to find out.

The plug fan has compact structure and requires less installation space. The absence of volute allows you to freely determine the airflow direction and is easy to clean. It is often used in static pressure boxes and modular AHUs.

The inlet and outlet direction of centrifugal fan is fixed, it needs more space to install, maintenance is a little more complex than plug fan. However, its static pressure capacity is higher, suitable for industrial ventilation, HVAC system, exhaust system, etc.

Why Choose Longwell Plug Fan?

Longwell plug fan uses EC motor, which saves more than 35% energy compared to traditional AC fans and greatly reduces electricity costs. Its belt-free design avoids transmission wear and tear, improving service life. The ball bearings we use can last up to 100,000 hours without frequent replacement.

From motor winding and impeller dynamics optimization to complete unit assembly, Longwell integrates a vertical supply chain to ensure that each fan is dynamically balanced, efficiency verified and 100% performance tested to ensure high quality and performance.

Longwell produces more than a million turbines per year and can deliver them quickly. Even for large orders, we can deliver them within 3-5 weeks.

Longwell Plug Fan Selection Chart

Plug Fan Drawing
ModelD1D2D3t1t2
RLM E-2801899032382114.8
RLM E-3152159036090126.65
RLM E-355241.590406100.5142.05
RLM E-400271110456113.5160
RLM E-450304110512127.8180.5
RLM E-500337110570142200
RLM E-560337.4140640160225.63
RLM E-630424.6140720180253.3
RLM E-710478170810202284.1
RLM E-800539.2170912229321
RLM E-9006061901023255359
RLM E-10006742201120285.91401

Catalogs & Brochures for Axial Fan

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What Our Customers Say

Common Applications of Plug Fan

Air Handling Units (AHUs) & Central HVAC Systems

Air Handling Units (AHUs) & Central HVAC Systems

Plug fans are ideal for central air systems in large buildings like commercial offices, hospitals, and schools. Because they can be integrated directly into the AHU without a housing, they offer a very compact design and flexible discharge direction. This high-efficiency, energy-saving solution provides the necessary power to move air throughout the entire system.
Data Center Cooling

Data Center Cooling

Data centers require constant, efficient heat removal, making high-efficiency EC plug fans the go-to choice. Often, multiple fans are arranged in a “fan wall” for redundancy and improved performance. This setup not only cuts down on persistent low-frequency noise but also guarantees stable operation in these precision-controlled environments.
Industrial Ventilation

Industrial Ventilation

Longwell plug fans can be integrated into a variety of industrial systems, including fume hoods, dust collection systems, and ductwork. They provide comprehensive ventilation for factory workshops, commercial kitchens, printing facilities, and other similar spaces. By effectively removing airborne dust and hot air, they help create a healthier working environment.
Pharmaceutical Industry

Pharmaceutical Industry

The compact, easy-to-seal design of plug fans is perfect for environments that require strict cleanliness standards, such as those meeting ISO Class 5. Their modular construction simplifies routine inspections, cleaning, and filter replacements. Plus, they offer remarkable energy savings compared to traditional AC motors.
Vehicle Ventilation

Vehicle Ventilation

Ventilation systems in subways, high-speed trains, and other vehicles demand fans that are small, lightweight, and highly reliable. Plug fans are a great choice because their rugged design can withstand the impacts of vehicle movement, ensuring long-term stable performance. Their low operating noise also helps improve passenger comfort.

High-Temperature Applications

Built with heat-resistant materials and specialized cooling features, plug fans can handle gases up to 650°C. This makes them perfect for high-temperature environments like ovens, dryers, and kilns. With optional explosion-proof and corrosion-resistant features, they deliver exceptional safety and durability, making them an ideal fit for drying systems in the paper industry.

FAQs of Longwell Axial Fan

1. How Much Energy can We Save Using a Plug Fan?
Thanks to its efficient backward-flowing centrifugal impeller and direct-drive design, a plug fan eliminates the energy losses associated with belt drives. Its EC motor is inherently highly efficient, and variable frequency speed regulation precisely matches airflow requirements to avoid over-output. This results in overall energy savings of typically 30%-50%.
Of course! A key advantage of a plug fan is its compact design. It lacks a bulky volute and can be installed directly into the equipment enclosure, significantly saving space inside the equipment and freeing up space for other components.

√ Beltless design: This eliminates the tedious task of regular belt replacement, tensioning, and lubricating bearings, as well as the efficiency losses caused by belt slippage.

√ Modular design: When the fan needs cleaning, inspection, or replacement, the entire fan module can be easily removed from the side of the unit, significantly reducing downtime.

√ Easy to Clean: The simple structure makes cleaning the impeller and interior of the housing easier, facilitating the maintenance of high cleanroom standards.

When selecting a plug fan, consider the following factors:
 

√ Airflow and Static Pressure Requirements: Based on the system’s required airflow and the required resistance, review the fan’s performance curve (P-Q curve) to ensure the operating point is within the high-efficiency range.

√ Installation Space Constraints: Confirm the size of the equipment’s static pressure box to ensure sufficient space for smooth airflow into the fan to avoid performance loss.

√ Environment and Media Characteristics: Does your application involve high temperatures, corrosive gases, or explosive environments? It’s best to select the appropriate material, ingress protection rating, and certification based on the environmental requirements.

Don’t worry; plug fans generally perform better in terms of noise control. They lack a volute, eliminating noise generated by interaction with the impeller. They are ideal for use in offices, hospitals, laboratories, and other locations with strict acoustic requirements.

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