The Double Inlet Centrifugal Fan is designed for air-conditioning equipment, ventilation cabinets, machinery cooling systems, and other installations that need steady airflow in a compact space. Available in the 133FLJ2/3/4/5 and 146FLJ4/5 series, this double inlet centrifugal fan combines a pure copper motor, a durable bearing structure, and an efficient centrifugal air path to support reliable air movement in industrial and commercial environments.

Unlike a simple single-side air intake design, a double inlet centrifugal fan draws air through both sides of the impeller and directs it through the outlet path. This construction helps create a balanced airflow pattern while making practical use of limited installation space. It is suitable for equipment manufacturers, maintenance teams, HVAC integrators, and buyers sourcing replacement fans for air-conditioning or ventilation systems.

A double inlet centrifugal fan is commonly used when a system needs concentrated airflow and efficient air delivery through a defined outlet direction. Air enters from both sides of the fan wheel, passes through the centrifugal impeller, and is guided toward the discharge outlet. This layout is widely used in air-conditioning units, ventilation assemblies, electronic equipment cooling systems, and enclosed machinery where airflow must be directed to a specific area.

The 133FLJ and 146FLJ series are built around a compact motor-and-impeller assembly. The fan body is designed for practical installation in equipment housings and ventilation compartments. Its centrifugal operating principle helps move air through ducts, heat exchangers, cabinet openings, and other restricted airflow paths where axial fans may not be the preferred configuration.

The motor uses copper windings and environmentally considered materials. Copper windings are commonly selected in fan motors for their electrical conductivity and thermal stability. Combined with the outer rotor motor design, the assembly supports fast rotation and a compact overall structure. For buyers, the important selection factors remain the confirmed model, mounting dimensions, voltage, power rating, airflow requirement, and available equipment space.

Pure Copper Motor Construction: The fan uses a pure copper winding motor designed for stable electrical operation. The outer rotor permanent-magnet brushless motor structure supports compact assembly, responsive rotation, and practical heat dissipation during normal operating use.

Double Inlet Airflow Design: This double inlet centrifugal fan draws air from both sides of the impeller. The airflow is then directed through the outlet for equipment ventilation, air-conditioning circulation, or cabinet cooling. This structure is useful where airflow needs to be collected and delivered in a controlled direction.

High-Density Bearing Assembly: The motor is equipped with a precision bearing structure. The close fit between bearing components helps support smooth rotation during extended use. Proper bearing design also contributes to lower mechanical friction, reduced vibration, and a more controlled operating sound level.

Efficient Centrifugal Ventilation: The centrifugal impeller is designed to move air through the fan housing and toward the intended outlet. This makes the fan suitable for applications involving heat exchangers, ventilation channels, equipment compartments, and other installations with airflow resistance.

Multiple Model Options: The 133FLJ2/3/4/5 and 146FLJ4/5 series provide different model choices for equipment matching. Buyers can compare technical parameters and CAD drawings to select a configuration that aligns with their installation opening, fan wheel size, required airflow, and electrical system.

Practical Material and Housing Design: The fan is made with durable materials intended for industrial and commercial equipment environments. Its compact structure can help equipment builders integrate a centrifugal ventilation component into air-conditioning units, cabinets, and machinery housings.

Because exact electrical and airflow values can vary by model, buyers should confirm the selected version against the corresponding technical parameter sheet before purchase.

Before ordering, please verify the required model number, voltage, rated power, airflow, noise level, mounting hole distance, overall dimensions, and impeller diameter. This helps ensure the selected double inlet centrifugal fan fits the intended equipment and airflow system.

The Double Inlet Centrifugal Fan can be considered for a range of ventilation and equipment cooling applications.

Air-conditioning equipment: Supports air circulation inside indoor units, packaged systems, and related HVAC assemblies.

Server rooms and electrical cabinets: Helps move air through cabinet spaces where electronic components generate heat.

Hotel kitchens and commercial ventilation: Can be integrated into ventilation equipment that requires directed airflow.

Large office areas: Supports air movement in commercial ventilation and air-conditioning systems.

Tunnels and infrastructure projects: Suitable for equipment ventilation systems where a centrifugal airflow component is required.

Agricultural and livestock buildings: Can support ventilation equipment used in barns, sheds, and controlled-environment facilities.

Chemical and industrial facilities: May be used in equipment cooling and enclosure ventilation, subject to application-specific environmental requirements.

For corrosive, humid, high-temperature, or dust-heavy environments, the final fan selection should be confirmed according to actual operating conditions and required protection level.

For equipment manufacturers and maintenance buyers, choosing a suitable double inlet centrifugal fan is not only about airflow. It is also about dimensional compatibility, documentation, sourcing continuity, and the ability to match the fan to an existing system.

This product series is supported by multiple model options, technical parameter references, and CAD dimensional drawings. These resources can help engineering teams review mounting openings, fan wheel diameter, installation spacing, and equipment layout before production or replacement work begins.

Factory-direct supply can simplify communication for customers who need larger quantities or model-specific purchasing support. Available stock helps buyers plan replacement orders and production schedules, while product images and technical documents make it easier to verify the required configuration before shipment.

When comparing a double inlet centrifugal fan with another airflow solution, the key question is how the air must move through the equipment. Centrifugal fans are typically selected when the system needs directional discharge through a housing, heat exchanger, or constrained airflow path. Selection should balance the required airflow against available installation space, electrical requirements, mounting geometry, and the resistance created by the surrounding system.

Technical drawings are important during this process. Checking the overall dimensions, mounting-hole distance, fan-wheel diameter, and discharge direction before ordering can reduce fitment issues during production or maintenance. The final choice should be based on the applicable model data rather than product type alone.

Q1: What is the difference between a double inlet centrifugal fan and an axial fan?
A double inlet centrifugal fan draws air through both sides of the fan wheel and redirects the airflow through an outlet. It is often used where airflow needs to pass through a housing, duct, heat exchanger, or equipment compartment. An axial fan moves air generally parallel to its shaft and is used in different installation conditions.

Q2: Which information is needed before selecting a fan model?
Please confirm the required model series, voltage, power, airflow, noise requirement, mounting hole distance, overall dimensions, and impeller diameter. CAD drawings and technical parameter sheets are useful for confirming installation compatibility.

Q3: Can this fan be used in air-conditioning equipment?
Yes. The series is intended for air-conditioning and ventilation-related equipment applications. The final model should be selected according to the specific airflow path, space limitation, electrical configuration, and operating environment.

Q4: Are technical drawings available?
Multi-specification CAD dimensional drawings are available for model selection and installation planning. They can help engineering teams check the fan body dimensions, mounting holes, and fan wheel diameter.