Section 1: Product Overview

The T35 Axial Flow Ventilation Fan represents the standard of general-purpose axial ventilation technology as applied to industrial and commercial building environments. The designation T35 places this fan in a well-established series of axial ventilation fans developed and standardized for the Chinese market, with the T indicating ventilation application and the 35 referring to the specific aerodynamic design series of the impeller blade profile. This series has been widely deployed across Chinese industrial and commercial construction for decades and remains the reference standard for general building ventilation fan specifications in this market segment.

The fundamental operating principle of the axial fan — moving air parallel to the axis of the impeller rotation — makes it inherently suited to applications requiring the movement of large volumes of air against relatively low system resistance. When airflow volumes are the primary performance requirement and static pressure demands are moderate, the axial configuration delivers this performance more efficiently and with lower noise than centrifugal alternatives of equivalent airflow capacity.

The T35 Axial Flow Ventilation Fan builds on this axial efficiency foundation with an impeller design specifically developed to maximize full-pressure efficiency across a wide operating range. The wide-blade, large-chord, space-twisted blade profile that characterizes the T35 series was developed through aerodynamic optimization to reduce flow separation losses, minimize blade tip vortex generation, and broaden the high-efficiency operating zone to cover the range of actual system conditions encountered in building ventilation applications.

Dezhou Pengkai Air Conditioning Equipment Co., Ltd. is a comprehensive HVAC manufacturer based in Dezhou, Shandong Province, integrating research and development, production, sales, installation, and after-sales service. We supply axial ventilation fan products to HVAC engineering contractors, industrial facility operators, building developers, and equipment distributors across Southeast Asia and global markets.

Section 2: Product Structure and Key Components

Impeller Assembly The impeller is the defining structural element of the T35 Axial Flow Ventilation Fan and the primary determinant of its performance characteristics. T35 series impeller blades are fabricated from steel plate using pressing processes that form the wide-chord, space-twisted aerodynamic profile characteristic of this series. Blades are riveted directly to the hub, creating a robust and permanent connection that maintains blade angle consistency throughout the service life of the unit. The blade angle is set at the factory according to the specified operating point for the selected machine number, with blade angle options typically ranging from 15 to 35 degrees to allow performance matching to different system resistance conditions.

Cylindrical Casing The fan casing is a cylindrical tube fabricated from steel plate by welding, providing a rigid structural housing for the impeller and motor assembly. The internal diameter of the casing is matched to the impeller tip diameter with a controlled clearance that balances minimizing tip leakage — which reduces efficiency — against practical manufacturing and assembly tolerances. Inlet and outlet flanges are provided at both ends of the casing for connection to ductwork or to wall and ceiling mounting frames.

Direct-Drive Motor The motor in the T35 Axial Flow Ventilation Fan is mounted axially within the airflow stream, with the impeller mounted directly on the motor shaft. This direct-drive configuration eliminates all belt, pulley, and coupling transmission components, achieving the highest possible mechanical efficiency between motor input power and fan shaft power. The motor is positioned in the center of the airflow path and is cooled by the airflow passing over its external surface, eliminating the need for a separate motor cooling system. Motor specifications cover single-phase 220V/50Hz and three-phase 380V/50Hz supply, with four-pole motors running at approximately 1450 rpm and six-pole motors running at approximately 960 rpm as the standard speed options for most machine numbers.

Support Frame The motor is connected to the casing by a structural support frame, typically a spider or cross-arm arrangement, that holds the motor centered within the airflow path while allowing air to pass around the frame members with minimal obstruction. The frame is dimensioned to provide adequate structural rigidity for the weight and operational loads of the motor while minimizing the flow blockage area that would reduce fan efficiency.

Optional Rain Cap For outdoor installations or installations where the fan outlet faces exposed outdoor conditions, a rain cap is available as an optional accessory. The rain cap mounts over the outdoor face of the fan casing and allows air discharge while preventing rain and snow entry into the fan and connected ductwork system.

Section 3: Technical Specifications

Representative Performance Data — Selected Machine Numbers:

Complete performance data tables for all machine numbers and blade angles are available upon request. Please contact our sales team with your airflow volume and static pressure requirements for model selection guidance.

Section 4: Aerodynamic Design — The T35 Blade Profile Advantage

The performance advantage of the T35 Axial Flow Ventilation Fan over older axial fan series such as the T30 originates in the aerodynamic design of its blade profile. Understanding this design advantage clarifies why the T35 series delivers higher efficiency and lower noise for the same airflow output compared to earlier designs.

Wide Chord and Large Blade Area The T35 blade profile uses a wider chord — the distance from the leading edge to the trailing edge of the blade — compared to narrower blade designs used in older fan series. The larger blade area allows the required lift force to be generated at a lower angle of attack, reducing the tendency for flow to separate from the blade surface at the operating point. Flow separation is a major source of both efficiency loss and aerodynamic noise in fan impellers, so reducing separation tendency directly improves both the efficiency and acoustic performance of the fan.

Space-Twisted Blade Geometry Axial fan impeller blades rotate through air that moves at different velocities relative to the blade at different radial positions — air at the blade tip moves much faster relative to the blade than air near the hub. A flat blade cannot maintain an efficient angle of attack across this velocity gradient simultaneously at all radial positions. The space-twisted blade geometry of the Low Noise Industrial Axial Fan varies the blade pitch angle progressively from hub to tip, maintaining an efficient angle of attack at each radial position across the full blade span. This spanwise optimization is the primary reason for the T35 series efficiency advantage over older flat-blade designs.

Inclined Blade Setting The blade attachment geometry uses an inclined setting that further reduces tip vortex generation and the associated noise and efficiency losses at the blade tip clearance. Together with the space-twisted profile, this design produces the broad high-efficiency operating zone that allows the T35 series to maintain near-peak efficiency across a practical range of system resistance conditions, rather than falling off rapidly from a narrow peak as simpler blade designs typically do.

Section 5: How It Works — Operating Principle

Axial Airflow Generation When the motor starts and the impeller rotates, the twisted blade profile generates lift forces perpendicular to the blade surface at each spanwise position. The axial component of these distributed lift forces across the full blade span drives air in the direction parallel to the fan axis, creating the through-flow that characterizes axial fan operation. The net result is a continuous column of moving air passing through the cylindrical casing from the inlet face to the outlet face.

Pressure Development As air accelerates through the rotating impeller, it gains both velocity energy and static pressure energy. The ratio of static to total pressure rise depends on the blade angle setting and operating point. At the design blade angle and system resistance, the T35 Axial Flow Ventilation Fan operates at peak efficiency, delivering the maximum ratio of useful airflow power output to motor input power.

Flow Uniformity The space-twisted blade geometry and cylindrical casing combine to produce relatively uniform velocity distribution across the outlet face of the fan. This uniformity is beneficial for applications where the fan discharges into a duct system, as non-uniform inlet velocity to ductwork fittings increases pressure losses in the connected system.

Motor Cooling The motor positioned within the airflow path is continuously cooled by the air flowing over its external surface. This cooling effect allows the motor to operate at lower winding temperatures than would be the case in still air, contributing to motor longevity and sustained performance over long operating periods.

Section 6: Manufacturing Process and Quality Control

Dezhou Pengkai Air Conditioning Equipment Co., Ltd. applies rigorous quality management throughout Large Airflow Duct Ventilation Fan production:

Steel Incoming Inspection Steel plate for blades and casings is inspected for dimensional compliance and surface quality on receipt. Material certification documents are retained for each production batch.

Blade Pressing and Profile Verification Blade blanks are cut and formed using precision pressing tooling that produces the specified space-twisted aerodynamic profile. Blade profile geometry is verified against the design template to ensure the aerodynamic characteristics that produce the T35 performance standard are achieved consistently across production runs.

Hub Assembly and Blade Riveting Blades are mounted to the impeller hub at the specified blade angle and riveted to produce a permanent, rigid connection. Blade angle consistency across all blades in the impeller is verified after assembly, as blade angle variation between blades increases vibration and noise.

Dynamic Balancing Each assembled impeller undergoes dynamic balancing to the grade required for smooth low-vibration operation. Correction weights are added at the specified correction planes as needed to achieve the balance standard. Dynamic balancing is essential for long bearing life and acceptable noise performance.

Casing Fabrication Casing cylinders are formed and welded from steel plate, with inlet and outlet flanges welded to the cylinder ends. Internal diameter dimensional accuracy is verified to ensure the tip clearance between the impeller and casing meets the specification.

Motor Installation and Electrical Verification Motors are installed in the support frame, connected to terminal blocks, and verified for correct insulation resistance and rated current draw before dispatch.

Final Running Test Every completed T35 Axial Flow Ventilation Fan undergoes a running test to verify smooth operation, correct rotation direction, acceptable vibration, and normal current draw before dispatch.

Section 7: Product Features and Advantages

Near-90% Peak Full-Pressure Efficiency The aerodynamically optimized T35 blade profile achieves peak full-pressure efficiency approaching 90 percent, significantly reducing operating energy costs compared to older fan series and alternative designs at equivalent airflow output.

Broad High-Efficiency Operating Zone The space-twisted blade geometry maintains high efficiency across a wide range of system resistance conditions, making the T35 Axial Flow Ventilation Fan tolerant of variation in actual system resistance from design values — an important practical advantage in real building ventilation systems where duct cleanliness, filter loading, and damper positions vary over time.

Low Rotational Speed for Quiet Operation Four-pole and six-pole motor options running at 1450 rpm and 960 rpm respectively allow the Low Noise Industrial Axial Fan to achieve the required airflow at lower tip speeds than higher-speed alternatives, directly reducing aerodynamic noise generation. The 960 rpm option is particularly recommended for noise-sensitive applications such as office buildings, schools, hospitals, and residential buildings.

Direct-Drive Simplicity The direct motor-shaft impeller drive eliminates belts, pulleys, and couplings, removing the maintenance requirements, mechanical losses, and failure modes associated with these transmission components. The only mechanical wear items in the direct-drive configuration are the motor bearings, which require only periodic lubrication in service.

Multiple Speed Options Two-pole (2900 rpm), four-pole (1450 rpm), and six-pole (960 rpm) motor options across the machine number range provide flexibility to match rotational speed, airflow output, noise level, and energy consumption to specific application requirements without requiring variable speed controllers.

Flexible Installation Configurations The cylindrical casing with inlet and outlet flanges supports wall mounting, column mounting, and inline duct installation configurations, allowing the Large Airflow Duct Ventilation Fan to be integrated into virtually any building ventilation system layout.

Wide Machine Number Range Machine numbers from No.2.8 to No.11.2 covering impeller diameters from 280mm to 1120mm provide airflow coverage from small individual room ventilation requirements to large industrial hall general ventilation, all within a consistent product platform with the same installation and maintenance approach.

Section 8: Application Scenarios

Industrial Workshops and Manufacturing Facilities Large factory production halls, assembly workshops, machining areas, and fabrication facilities require general ventilation fans capable of moving large air volumes to control heat buildup, dilute process fumes, and maintain acceptable working environment conditions. The T35 Axial Flow Ventilation Fan in larger machine numbers provides the high-volume airflow required for industrial hall ventilation at competitive energy cost.

Warehouses and Distribution Centers Large warehouse and distribution center buildings require ventilation to control temperature buildup under metal roofs during warm weather. Wall-mounted T35 fans in medium to large machine numbers, combined with appropriately positioned fresh air inlets, provide effective cross-ventilation for warehouse temperature management.

Office Buildings and Commercial Spaces Office buildings, retail spaces, and commercial facilities require ventilation that balances adequate air change rates with acceptably low noise levels. The Low Noise Industrial Axial Fan at 960 rpm speed in appropriate machine numbers delivers the required ventilation performance while maintaining sound levels compatible with occupied commercial environments.

Schools and Educational Buildings Classroom ventilation, gymnasium exhaust, workshop ventilation in vocational training facilities, and canteen exhaust in school buildings all represent applications for medium machine number T35 fans operating at low speed for quiet, reliable ventilation service.

Residential Buildings Stairwell ventilation, underground car park ventilation, and plant room ventilation in residential high-rise buildings require reliable, cost-effective axial fans for continuous or scheduled operation. The small and medium machine number range of the T35 Axial Flow Ventilation Fan serves these building service applications throughout the residential construction sector.

Cooling Towers and Heat Exchangers Forced-draft and induced-draft cooling tower applications, air-cooled condenser banks, and industrial heat exchanger cooling systems require large-volume low-pressure axial fans to move cooling air across heat transfer surfaces. Large machine number T35 fans are applied in this role in industrial cooling system installations.

Air Conditioning System Components As a component within air handling unit systems, fresh air handling systems, and return air systems, the Large Airflow Duct Ventilation Fan provides the primary air movement function in medium-scale ventilation system configurations where system static pressure requirements fall within the T35 performance range.

Agricultural and Greenhouse Facilities Greenhouse ventilation, poultry house ventilation, and agricultural storage facility air management applications require high-volume fans for temperature and humidity control. Medium machine number T35 fans provide the necessary air change rates for these applications in an economical product format.

Section 9: Customer Application Feedback

Our T35 axial ventilation fan products have been supplied to industrial, commercial, and institutional projects across Southeast Asia and international markets. The following reflects representative feedback:

"We specified Pengkai T35 fans for general ventilation in a large manufacturing facility. The selection of 960 rpm motors in the larger machine numbers gave us acceptable noise levels on the factory floor while delivering the required air change rates. Energy consumption has been consistent with the specification estimates, and we have had no motor or mechanical failures across the installation after 18 months of operation." — Industrial Facility Manager, Southeast Asia

"For a school building project, we needed ventilation fans that would operate quietly in classroom areas while providing effective air circulation. The Pengkai Low Noise Industrial Axial Fan at 960 rpm delivered the noise levels required by the design specification and passed the acoustic testing during commissioning. The supply and export documentation were complete and correctly prepared." — Building Services Consultant, Regional Project

"We have standardized on Pengkai T35 fans for warehouse ventilation projects across our portfolio. The consistent product quality, reliable after-sales support for replacement parts, and straightforward installation have made them our go-to specification for this application type." — HVAC Engineering Contractor

Section 10: Installation Guidelines

Pre-Installation Checks Verify that the machine number, blade angle, motor speed, power supply voltage, and dimensional specifications match the project design documents. Open the fan packaging and inspect the impeller, casing, motor, and accessories for transport damage. Rotate the impeller by hand to confirm it turns freely without contact with the casing or support frame.

Mounting Base and Support For floor-mounted installations, the fan must be mounted on a level, rigid concrete or steel base capable of supporting the fan weight and operational vibration loads. Anti-vibration mounts — rubber pads or spring isolators — should be installed between the fan base and the mounting surface to reduce vibration transmission to the building structure. For wall and column mounting, verify that the mounting surface structural capacity is adequate for the fan weight with a suitable safety factor.

Ductwork Connection Connect inlet and outlet ductwork to the fan flanges using flexible connectors — fire-rated fabric sleeves are the standard recommendation. Flexible connectors prevent fan vibration from transmitting into the duct system and allow for slight misalignment between fan flanges and duct flanges. Ductwork must be independently supported and must not transfer weight or stress to the fan casing flanges.

Airflow Direction Verification Before completing the installation, confirm that the intended airflow direction through the fan matches the direction indicated by the arrow on the fan casing. For three-phase motors, this verification should be done during the initial rotation direction check before final ductwork connection.

Electrical Connection Electrical connection must be performed by a qualified electrician. Verify supply voltage and phase configuration match the motor nameplate. Connect supply cable and earth conductor securely. For three-phase motors, check rotation direction with a brief test start before completing ductwork connection — reverse any two supply phase connections if rotation is in the wrong direction.

Space Requirements Maintain a minimum free space of 1.5 times the fan diameter at both the inlet and outlet faces to ensure undisturbed airflow approach and discharge. Obstructions closer than this minimum distance will reduce fan performance and increase noise.

Section 11: Maintenance Schedule

Monthly Inspection Listen for changes in operating noise or vibration that may indicate developing bearing wear or impeller imbalance from accumulated dust. Check that the fan is securely mounted and that no vibration has loosened mounting fasteners.

Quarterly Cleaning Clean the impeller blades and casing interior of accumulated dust using a soft brush or low-pressure compressed air with the power isolated. Uneven dust accumulation on impeller blades causes imbalance and should be removed promptly when observed.

Annual Motor Bearing Lubrication For motors with grease nipples, apply the specified grease type and quantity per the motor manufacturer's recommendation annually. Sealed bearing motors require no lubrication service. Check motor terminal connections for tightness.

Impeller Inspection Inspect impeller blades for cracks, deformation, or corrosion damage annually. Any blade damage that alters the blade profile or mass distribution will cause imbalance and must be addressed before continued operation.

Section 12: Packaging, Shipping, and Lead Time

Packaging Each T35 Axial Flow Ventilation Fan unit is packaged in protective carton packaging with foam corner and edge cushioning. For larger machine numbers, wooden crate packaging is used to provide adequate protection during handling and sea freight transit. Accessories and hardware are packed with the unit. Larger project orders are palletized for container loading.

Minimum Order Quantity We accept both small-quantity sample orders and large-volume project supply contracts. Please contact our sales team to discuss project requirements and volume pricing.

Lead Time Standard machine numbers in common speed and voltage configurations are held in warehouse stock for short lead times. Non-standard blade angle specifications, special motor configurations, and machine numbers outside the standard stocked range are produced to order with lead times confirmed at order placement.

Shipping We ship from Dezhou, Shandong Province. Sea freight, air freight, and international express courier options are available. We work with established freight forwarding partners serving Southeast Asia, the Middle East, and global destinations. FCL and LCL sea freight options are available for project-volume orders.

Sample Policy Product samples are available for pre-order specification and quality verification. Sample costs and shipping fees are agreed prior to dispatch. We recommend buyers inspect samples before placing full project orders.

Payment Terms We support T/T bank transfer and other payment arrangements as mutually agreed. Please contact our sales team to discuss terms appropriate to your order volume and procurement process.

Section 13: Certifications and Quality Assurance

Dezhou Pengkai Air Conditioning Equipment Co., Ltd. manufactures T35 axial ventilation fan products in compliance with applicable national standards for industrial and Commercial Ventilation fans. Production quality management covers incoming material inspection, in-process blade profile verification, dynamic balance testing of impeller assemblies, and finished product running tests. Product quality documentation is maintained for each production batch and available to buyers on request. Third-party pre-shipment inspection by buyer-nominated agencies is welcomed for project-specific orders.