The Square Wall-Mounted Axial Ventilation Fan addresses a specific and common need in building ventilation system design — providing reliable, high-volume forced exhaust or supply ventilation through a wall opening in a format that is structurally straightforward to install, architecturally clean in appearance, and mechanically durable over extended service periods in environments where the exhaust air quality would otherwise degrade motor performance.
The square housing format is the starting point for the practical advantages of this product. Rectangular wall openings are structurally simpler to form in masonry, concrete, and steel-frame wall constructions than circular openings of equivalent area. Square openings allow standard masonry block or lintel construction at the opening head without requiring specialist curved formwork, and the resulting square frame installation presents a regular, symmetric appearance on the wall surface that integrates naturally with building interior and exterior finishes.
Within this square housing, the axial impeller delivers the characteristic axial fan performance profile — high airflow volume at low to moderate static pressure, achieved efficiently and at low noise — making the Square Wall-Mounted Axial Ventilation Fan the appropriate choice for applications where the ventilation requirement is high air change rates rather than high outlet pressure. The housing includes an internal bell-mouth inlet profile that guides incoming airflow smoothly onto the impeller face, reducing inlet turbulence and the associated efficiency and noise penalties that occur with abrupt-entry axial fan configurations.
The external motor position is what distinguishes the Square Wall-Mounted Axial Ventilation Fan from simpler axial wall fan designs. By locating the motor outside the airflow passage, this design preserves full motor performance and reliability regardless of the temperature, humidity, grease content, or chemical composition of the exhaust airstream. The motor operates in clean ambient air at all times, using standard motor protection ratings rather than requiring elevated protection specifications to compensate for direct exhaust stream exposure.
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 square wall-mounted ventilation fan products to HVAC contractors, building developers, industrial facility operators, and equipment distributors across Southeast Asia and global markets.
Square Housing and Frame The outer housing is fabricated from high-quality galvanized steel sheet or cold-rolled steel sheet with powder-coated or baked enamel surface treatment, providing corrosion resistance and a clean finished appearance. The square cross-section is formed to precise dimensional tolerances, with corner joints produced by riveting or clinching rather than welding to preserve the galvanized coating at joint areas. The housing includes an internal bell-mouth or trumpet-shaped inlet flow guide that channels incoming air smoothly onto the impeller face, reducing inlet turbulence and improving fan efficiency relative to a plain square-edged opening. Installation mounting ears with bolt holes are provided at the four corners of the housing frame for direct fixing to wall surfaces using expansion bolts into masonry and concrete, or screw fixing to metal stud framing.
Axial Impeller The impeller uses low-speed, large-chord, forward-swept or aerofoil-section twisted blade geometry, fabricated from aluminum alloy or engineering plastic. Aluminum alloy blades offer a combination of light weight, high specific stiffness, and natural corrosion resistance that makes them well suited to the wall-mounted ventilation environment. Engineering plastic impellers are used in smaller machine numbers where weight reduction is less critical and material cost efficiency is prioritized. All impellers are dynamically balanced after assembly to minimize vibration and bearing loads during operation.
External Drive Motor The motor is mounted externally to the housing on a dedicated bracket that positions it outside the main airflow passage. Drive transmission from the motor to the impeller uses a direct shaft connection or, in some configurations, a short drive arrangement that maintains the motor in the external position. The external motor position means the motor operates continuously in clean ambient air, experiencing none of the elevated temperature, humidity, grease, solvent vapor, or corrosive gas conditions that may be present in the exhaust airstream. Motor protection grade is IP54 as standard, with IP55 available for outdoor-facing or high-humidity installations. Insulation class F is standard. Single-phase 220V/50Hz and three-phase 380V/50Hz configurations are available across the size range.
Aluminum Alloy Gravity Louvers The standard outdoor face fitting is an aluminum alloy gravity louver assembly, in which individual louver blades are suspended on pivot shafts and held in the closed position by gravity when no airflow is present. When the fan operates and positive pressure builds at the outlet face, the airflow pressure overcomes the gravity closing force and pushes the louver blades to the open position, allowing free air discharge. When the fan stops and outlet pressure drops, the louver blades return to the closed position under gravity. This passive open-close mechanism requires no actuator, control signal, or power supply, providing automatic backdraft prevention, wind ingress prevention, insect exclusion, and thermal draft prevention during all shutdown periods.
Protective Safety Screen A metal protective screen is fitted at the indoor face of the fan, preventing accidental contact with the rotating impeller from the indoor side and blocking the entry of large debris into the airflow path. The screen is removable for cleaning and impeller inspection.
Optional Control Box A dedicated control box is available as an optional accessory for applications requiring local start-stop switching, speed control, timer operation, or integration with building management systems. The control box is sized and specified to match the motor electrical characteristics of the selected fan model.
Parameter | Specification |
Fan Type | Square wall-mounted axial |
Housing Material | Galvanized steel / Cold-rolled steel, powder-coated |
Impeller Material | Aluminum alloy / Engineering plastic |
Motor Position | External — outside airflow stream |
Motor Protection Grade | IP54 standard / IP55 optional |
Motor Insulation Class | Class F |
Power Supply | Single-phase 220V/50Hz / Three-phase 380V/50Hz |
Power Range | 0.04 kW ~ 1.5 kW |
Airflow Range | Approx. 950 ~ 20,000+ m³/h |
Static Pressure Range | Approx. 41 ~ 250 Pa |
Noise Level | ≤ 55 ~ 75 dB(A) depending on model |
Standard Outdoor Fitting | Aluminum alloy gravity louver |
Indoor Safety Screen | Metal protective screen, removable |
Operating Speed | 1450 rpm standard |
Housing Sizes | 300×300mm / 400×400mm / 500×500mm / 600×600mm / 700×700mm and above |
Operating Temperature | -10°C ~ +60°C standard |
Optional Accessories | Control box, variable speed controller, inlet filter |
Representative Performance Data:
Machine No. | Airflow (m³/h) | Static Pressure (Pa) | Power (kW) | Noise dB(A) | Weight (kg) |
2.8 | 950 ~ 1650 | 41 ~ 58 | 0.04 ~ 0.06 | ≤55 ~ 60 | 18 ~ 20 |
3.2 | 1720 ~ 2250 | 56 ~ 68 | 0.04 ~ 0.09 | ≤61 ~ 63 | 21 ~ 27 |
3.6 | 2010 ~ 3370 | 65 ~ 76 | 0.06 ~ 0.12 | ≤62 ~ 63 | 28 ~ 35 |
4.0 | 3540 ~ 4470 | 89 ~ 109 | 0.12 ~ 0.25 | ≤62 ~ 63 | 37 ~ 41 |
4.5 | 4510 ~ 6360 | 114 ~ 139 | 0.18 ~ 0.37 | ≤64 ~ 66 | 42 ~ 49 |
5.0 | 6170 ~ 7890 | 135 ~ 147 | 0.25 ~ 0.55 | ≤65 ~ 68 | 50 ~ 63 |
Complete performance data for all machine numbers available upon request. Contact our sales team with airflow and static pressure requirements for model selection guidance.
The positioning of the drive motor relative to the exhaust airstream is one of the most consequential design decisions in wall-mounted ventilation fan engineering, with direct implications for motor service life, maintenance frequency, and total cost of ownership over the installed life of the equipment. Understanding this distinction is important for specifying the correct product for each application.
Inline Motor Design — Limitations in Demanding Environments In conventional axial wall fans where the motor is positioned directly within the airflow path, the motor is continuously exposed to whatever the exhaust air contains. In clean-air general ventilation applications, this exposure is relatively benign. However, in the many real-world ventilation applications where exhaust air carries elevated temperature, moisture, grease particles, solvent vapors, chemical fumes, ammonia, or fine particulates, the inline motor faces conditions that progressively degrade insulation, contaminate bearings, and reduce motor cooling effectiveness. The result is accelerated motor aging, increased failure rates, and higher maintenance and replacement costs compared to motors operating in clean ambient conditions.
External Motor Design — Consistent Performance in Any Exhaust Environment The External Motor Wall Exhaust Fan resolves this problem by removing the motor entirely from the exhaust airflow path. The motor mounted externally operates in the clean ambient air of the installation environment at all times, regardless of what the exhaust air contains. This means the motor experiences none of the temperature elevation, moisture absorption, grease deposition, or chemical attack that degrades inline motors in demanding environments.
In practical terms, this design choice significantly extends motor service life in kitchen exhaust applications where grease-laden air would rapidly foul inline motor windings, in workshop ventilation where solvent and process vapors attack motor insulation, in agricultural facility ventilation where ammonia and moisture combinations create highly corrosive conditions, and in any application where exhaust air temperature is elevated above the ambient conditions for which standard motor insulation classes are rated.
The Aluminum Louver Wall Ventilation Fan with external motor is therefore the technically correct specification choice for any ventilation application where exhaust air quality is degraded relative to clean ambient air, providing a measurably longer service life and lower total maintenance cost compared to inline motor alternatives at comparable initial equipment cost.
Fan Start and Airflow Initiation When the motor starts and the impeller begins rotating, the axial blade geometry generates a pressure difference between the inlet and outlet faces of the fan. The higher pressure at the outlet relative to the inlet drives airflow through the fan housing from the indoor inlet face to the outdoor outlet face, drawing room air in from the indoor space and discharging it through the aluminum louver assembly to the outdoor environment.
Gravity Louver Opening As airflow pressure builds at the outlet face during fan startup, the pressure force acting on the closed louver blades increases until it overcomes the gravity closing moment of each blade. The louver blades pivot open to their fully open position and remain open throughout fan operation, presenting minimal resistance to the discharge airflow.
Continuous Ventilation Operation During continuous operation, the Square Wall-Mounted Axial Ventilation Fan maintains a steady negative pressure within the ventilated space, driving fresh outdoor air to enter through windows, doors, or dedicated fresh air inlets on the opposite side of the building, creating a complete cross-ventilation circuit that continuously exchanges room air with fresh outdoor air.
Automatic Louver Closure on Fan Stop When the fan stops and outlet pressure drops, the louver blades return to the closed position under gravity. This closure happens passively within seconds of fan stop, without requiring any control signal or power supply. The closed louver position seals the wall opening against backdraft, wind-driven rain, cold air infiltration, and insect entry for the full duration of the shutdown period.
Motor External Cooling The external motor operates in clean ambient air with natural convection cooling supplemented by the induced airflow around the motor housing generated by fan operation. This effective cooling maintains motor winding temperatures within the rated insulation class limits throughout normal operation.
Dezhou Pengkai Air Conditioning Equipment Co., Ltd. applies systematic quality management throughout Square Wall-Mounted Axial Ventilation Fan production:
Steel and Material Incoming Inspection Galvanized steel sheet, cold-rolled steel sheet, aluminum alloy sheet for impellers and louvers, motor units, and hardware components are inspected against specification on receipt. Motor units are tested for insulation resistance and rated current before entering assembly. Material certification records are retained for each production batch.
Housing Fabrication Housing components are cut, formed, and joined using controlled processes that preserve the galvanized surface coating at all joint areas. The internal bell-mouth inlet profile dimensions are verified after forming to ensure the inlet flow guide geometry is consistent with the design specification.
Impeller Fabrication and Dynamic Balancing Aluminum alloy impeller blades are formed to the specified aerodynamic profile and assembled onto the hub at the specified blade angle. Each completed impeller undergoes dynamic balancing to the required grade, with correction weights added as needed. Balance quality at this stage directly determines the vibration and noise performance of the completed fan.
Louver Assembly Aluminum alloy louver blade components are assembled onto pivot shafts within the louver frame and verified for correct gravity-closing operation. Each blade is checked to confirm it returns smoothly to the fully closed position under gravity from any open position, without sticking or binding.
External Motor Mounting and Alignment The motor is mounted on its external bracket and aligned with the impeller drive interface. Drive connection geometry is verified to ensure concentric alignment, minimizing vibration from drive eccentricity.
Final Running Test Each completed External Motor Wall Exhaust Fan undergoes a running test verifying correct rotation direction, smooth impeller operation, louver opening and closing function, and motor current within the rated range before dispatch.
External Motor Protects Against Exhaust Stream Degradation The motor operates exclusively in clean ambient air, protected from heat, moisture, grease, chemical vapors, and particulates in the exhaust stream. This design choice delivers measurably extended motor service life in kitchen, workshop, agricultural, and industrial exhaust applications compared to inline motor designs.
Aluminum Alloy Gravity Louver — Passive Backdraft Prevention The standard aluminum alloy gravity louver provides automatic backdraft prevention, wind ingress prevention, and insect exclusion during shutdown periods without requiring any actuator, control wiring, or power supply. The passive operation mechanism has no wearing parts or electrical components that require maintenance.
Square Housing for Simple Installation The square format housing simplifies wall opening construction in masonry and concrete walls, aligns with standard building module dimensions, and presents a clean, symmetric appearance on wall surfaces. The four-corner mounting ear configuration allows straightforward fixing to any wall construction type.
Low Noise Operation Large-chord, low-speed impeller design combined with smooth bell-mouth inlet flow guidance and dynamic balancing produces noise levels from ≤55 dB(A) in small machine numbers to ≤75 dB(A) in larger models — acceptably low for commercial, educational, and light industrial environments.
Wide Size Range Housing sizes from 300×300mm to 700×700mm and above, with corresponding airflow outputs from 950 to over 20,000 m³/h, cover the full range of individual room to large-hall ventilation requirements within a consistent product platform.
Explosion-Proof Option Available For applications in environments containing flammable or explosive gases — chemical storage areas, paint spray booths, solvent handling areas — an explosion-proof motor configuration is available, allowing the Aluminum Louver Wall Ventilation Fan to be safely applied in classified hazardous areas.
Variable Speed Control Compatibility The fan is compatible with external variable speed controllers for applications requiring adjustable ventilation rates matched to occupancy, temperature, or process conditions.
Industrial Workshops and Production Facilities The Square Wall-Mounted Axial Ventilation Fan provides effective general exhaust ventilation for factory production floors, assembly areas, welding shops, and light manufacturing facilities. The external motor design handles elevated temperature and process fume conditions without the motor degradation that would occur with inline motor designs in these environments.
Commercial Kitchens and Food Service Areas Grease-laden exhaust air from commercial kitchen cooking operations represents one of the most demanding environments for fan motor longevity. The External Motor Wall Exhaust Fan is the appropriate specification for kitchen exhaust positions where the motor would otherwise be directly exposed to grease particles, elevated temperatures, and steam — all of which progressively degrade inline motor performance. The external motor position eliminates this degradation mechanism entirely.
Sports Venues and Gymnasiums Large sports halls, gymnasiums, indoor swimming pool facilities, and leisure centers require high-volume ventilation to manage heat buildup, humidity, and body odor from high-occupancy sporting activities. The wide airflow range of larger machine number configurations serves these high-volume ventilation requirements, with external motor reliability suited to the humid conditions in swimming pool and wet sports environments.
Food Processing and Pharmaceutical Production Clean production environments in food processing, beverage production, and pharmaceutical manufacturing require ventilation equipment that maintains hygiene standards. The Aluminum Louver Wall Ventilation Fan with external motor avoids motor component exposure to the production environment, and the aluminum alloy impeller and louver materials are resistant to the cleaning agents used in food-grade production area washdown procedures.
Entertainment Venues and Public Assembly Buildings Cinemas, theaters, indoor entertainment venues, and public assembly halls require ventilation equipment that operates quietly during events. The low-noise performance of the Square Wall-Mounted Axial Ventilation Fan at lower machine numbers is compatible with background noise requirements in these occupancy types.
Agricultural and Livestock Facilities Poultry houses, pig farms, aquaculture facilities, and greenhouse growing environments require high-volume ventilation to manage heat, humidity, ammonia, and carbon dioxide. The ammonia-rich, high-humidity atmosphere in livestock buildings is highly corrosive to motor windings — the external motor design of this product provides the motor protection required for reliable long-term operation in these conditions.
Underground Car Parks and Basement Spaces Underground car parking structures and basement mechanical spaces require mechanical ventilation for vehicle emission dilution and general air quality management. Wall-mounted installation in perimeter or intermediate walls provides effective zonal ventilation without requiring overhead duct system installation.
Our square wall-mounted axial ventilation fan products have been supplied to commercial, industrial, and institutional projects across Southeast Asia and international markets:
"We installed Pengkai square wall fans with external motors in a commercial kitchen exhaust application. After two years of operation in a grease-laden exhaust environment, the motors remain in good condition — the external motor position has clearly made the difference compared to the inline motor fans we used previously that required motor replacement within twelve months in the same environment." — Commercial Kitchen Fit-Out Contractor, Southeast Asia
"For a livestock facility ventilation project, we specified the external motor configuration specifically because of the ammonia and high-humidity conditions in the building. After eighteen months of continuous operation, we have had no motor failures across the installation. The aluminum louver function is reliable and the fans have required only basic cleaning maintenance." — Agricultural Facility Operator, Regional Project
"We have used Pengkai External Motor Wall Exhaust Fan products across multiple sports hall and gymnasium projects. The noise levels are acceptable for occupied sports facilities, and the build quality is consistent across supply batches. After-sales support for technical queries has been helpful." — Building Services Engineering Company
Pre-Installation Checks Verify that the housing size, machine number, motor voltage, and airflow specification match the project design documents. Confirm that the wall opening dimensions are correct for the selected housing size before beginning installation. Inspect the housing, impeller, louver assembly, motor, and safety screen for transport damage.
Wall Opening Preparation The wall opening should be formed to the nominal dimensions for the selected housing size, with the opening perimeter smooth and structurally sound. For masonry walls, ensure that the opening lintel or header provides adequate structural support above the opening and that cutting debris is removed before installation.
Fan Positioning and Leveling Insert the fan housing into the wall opening from the indoor face and adjust to level and square position using a spirit level and square. Verify that the outdoor face of the housing is flush with or slightly recessed from the outdoor wall surface to allow the louver assembly to open and close without obstruction.
Fixing and Sealing Fix the mounting frame to the wall at the four corner mounting ear positions using expansion bolts into masonry or concrete, with bolt sizes appropriate to the fan weight. Apply weatherproof sealant to the gap between the housing frame perimeter and the wall opening on both indoor and outdoor faces. Allow sealant to cure before operating the fan.
Electrical Connection Electrical connection must be performed by a qualified electrician. Verify supply voltage matches the motor nameplate. Connect supply cable using weatherproof cable glands appropriate to the installation environment. Ensure reliable protective earth connection. For three-phase units, verify correct rotation direction before completing the installation.
Louver Function Check After installation and before first operation, manually move each louver blade through its full travel range to confirm it opens and closes freely without binding. Verify that all blades return to the closed position under gravity from the open position.
Post-Installation Commissioning Run the fan for a minimum of 15 minutes at first start, monitoring for abnormal noise, vibration, or excessive current draw. Verify that all louver blades open correctly during fan operation.
Monthly Inspection Inspect the outdoor louver assembly and indoor safety screen for dust accumulation, grease deposits, or physical damage. Verify that louver blades move freely and return to the closed position correctly. For kitchen exhaust installations, monthly cleaning of the louver blades and housing interior is recommended to prevent grease accumulation.
Quarterly Cleaning Clean the impeller blades, housing interior, louver assembly, and safety screen using a soft brush or low-pressure compressed air with power isolated. Heavy grease deposits on impeller blades cause aerodynamic imbalance and must be removed when observed.
Annual Inspection Check motor bearing condition by listening for unusual noise during operation. Verify that all mounting fasteners remain tight. Inspect sealant at the housing frame perimeter and reapply if cracking or detachment is observed. Check motor terminal connections for tightness.
Lubrication For motors fitted with grease nipples, apply the specified grease type and quantity annually per motor manufacturer recommendation. Sealed bearing motors require no lubrication service.
Packaging Each Square Wall-Mounted Axial Ventilation Fan unit is individually packaged in protective carton packaging with foam corner and edge cushioning. The aluminum louver assembly and safety screen are packed separately within the carton to prevent damage during transit. Larger project orders are palletized and stretch-wrapped. Export-grade packaging is available for sea freight shipments to Southeast Asia and international destinations.
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 housing sizes in common motor configurations are held in warehouse stock for short lead times. Non-standard sizes, explosion-proof motor configurations, and special voltage requirements 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 all 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 quality and specification 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 procurement process and order volume.
Dezhou Pengkai Air Conditioning Equipment Co., Ltd. manufactures square wall-mounted axial ventilation fan products in compliance with applicable national standards for industrial and Commercial Ventilation fans. Each production batch is subject to incoming material inspection, dynamic balance testing of impeller assemblies, louver function verification, and finished product running tests before release. Product quality documentation is maintained for each production batch and available on request. Third-party pre-shipment inspection by buyer-nominated agencies is welcomed for project-specific orders.
What is a Square Wall-Mounted Axial Ventilation Fan?
A square wall-mounted axial ventilation fan is a forced ventilation device designed for installation in a square wall opening, combining an axial impeller for high-volume low-pressure airflow delivery with a square housing that simplifies wall opening construction and provides a clean, integrated appearance on building wall surfaces.
The axial impeller operates by generating lift forces on its twisted blade profile as it rotates, driving air parallel to the fan axis from the indoor inlet face to the outdoor outlet face. This axial operating principle delivers high airflow volume at low to moderate static pressure efficiently and at low noise, making it the appropriate choice for general building ventilation applications where air change rate is the primary requirement.
The external motor design is the defining technical feature of this product category. By positioning the drive motor outside the main airflow passage, the motor operates continuously in clean ambient air regardless of the temperature, humidity, grease content, or chemical composition of the exhaust airstream. This protects motor insulation, bearings, and cooling efficiency from the degradation that occurs when motors are directly exposed to contaminated exhaust air in kitchen, workshop, agricultural, and industrial ventilation applications. The result is significantly extended motor service life and lower total maintenance cost compared to inline motor designs in demanding exhaust environments.
Standard equipment includes an aluminum alloy gravity louver at the outdoor discharge face. Each louver blade opens under airflow pressure when the fan operates and closes under gravity when the fan stops, providing automatic backdraft prevention, wind ingress prevention, and insect exclusion during shutdown periods with no actuator or electrical components required.
The Square Wall-Mounted Axial Ventilation Fan is available in housing sizes from 300×300mm to 700×700mm and above, covering airflow outputs from 950 to over 20,000 m³/h and static pressures from 41 to 250 Pa. Applications include industrial workshops, commercial kitchens, sports venues, food processing facilities, agricultural buildings, entertainment venues, underground car parks, and general commercial building ventilation.
Dezhou Pengkai Air Conditioning Equipment Co., Ltd. is a professional HVAC manufacturer based in Shandong Province, integrating R&D, production, sales, and after-sales service. Products include fans, dampers, fan coil units, cooling towers, water tanks, and related systems. ISO 9001 certified and CE compliant, Pengkai serves customers across Southeast Asia, the Middle East, Europe, and Africa, offering OEM and ODM services with efficient global delivery.
Luqiantun Tengzhuang Industrial Park, Dezhou City, Shandong Province
pengkaihvac@gmail.com
+86 538 6340005
WhatsApp；2132469498
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