The Centrifugal Fire Smoke Exhaust Fan represents the highest tier of building mechanical smoke exhaust equipment, combining in a single cabinet unit the two ventilation functions that modern building fire safety design requires: reliable daily ventilation for indoor air quality management, and high-capacity emergency smoke exhaust for fire life safety. Buildings of significant scale and complexity cannot afford to install dedicated equipment for each function separately when space, cost, and installation complexity can all be reduced by a single unit that performs both roles reliably and switches between them automatically when a fire alarm is triggered.
The cabinet enclosure that characterizes this product category is not simply a structural housing — it is a functional component of the fire protection performance. The enclosure walls are constructed from double-layer steel sheet with an internal layer of acoustically absorbent and thermally insulating material. This construction simultaneously reduces the noise transmitted from the high-speed centrifugal fan to the surrounding building environment during both daily ventilation and emergency smoke exhaust operation, and provides thermal separation between the high-temperature smoke passing through the fan and the external environment of the equipment room in which the unit is installed.
The external motor position is fundamental to the fire protection performance of the Centrifugal Fire smoke exhaust fan. By mounting the motor outside the main airflow passage and connecting it to the fan impeller through a transmission arrangement that maintains this separation, the design ensures that the motor operates in clean ambient air at normal temperatures throughout the fire event, even as 280°C smoke passes through the fan impeller and scroll housing. This thermal isolation of the motor from the smoke stream is what enables the unit to sustain operation for the required 60-minute minimum duration at 280°C without motor failure.
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 centrifugal fire smoke exhaust fan products to fire protection engineering contractors, HVAC system integrators, building developers, and mechanical and electrical consultants across Southeast Asia and global markets.
Cabinet Enclosure The cabinet frame is constructed from cold-formed aluminum alloy section extrusions, providing a lightweight yet rigid structural framework that is inherently corrosion-resistant without requiring surface treatment. Panel infill between the frame sections uses double-layer steel sheet with an internal acoustic and thermal insulating material — typically a mineral wool or equivalent fire-rated insulating fill. This composite panel construction achieves two performance objectives simultaneously: acoustic attenuation of fan noise transmitted through the cabinet walls, and thermal insulation that limits temperature rise on the cabinet exterior surface during high-temperature smoke exhaust operation. The enclosure is designed to allow complete disassembly for transportation through restricted access routes in buildings where the assembled unit cannot be moved directly to its installation position.
Double-Inlet Centrifugal Fan Impeller and Scroll The centrifugal fan at the core of the Centrifugal Fire Smoke Exhaust Fan uses a double-inlet configuration in which air is drawn into the fan from both sides of the impeller simultaneously, doubling the effective inlet area relative to a single-inlet design of the same impeller diameter. This configuration allows a given airflow volume to be achieved at lower inlet velocity, reducing inlet losses and noise. The impeller uses backward-curved or aerofoil-section blades produced by tooling-controlled manufacturing processes, with static and dynamic balance correction to the grade required for smooth operation at both low-speed and high-speed operating conditions. The scroll housing is mechanically processed to achieve the dimensional accuracy required for consistent performance across production batches.
External Motor and Transmission The motor is mounted on a bracket external to the main airflow passage, connected to the fan impeller through a belt and pulley or direct-shaft transmission that spans the enclosure wall separating the motor compartment from the airflow path. The external motor mounting ensures the motor operates in clean, ambient-temperature air throughout the fire event. For the dual-speed configuration, the motor incorporates two independently wound stator circuits — a high-speed winding for emergency smoke exhaust mode and a low-speed winding for daily ventilation mode — with automatic switching between modes on receipt of the fire alarm signal from the building fire alarm control panel.
Acoustic and Thermal Lining The internal surfaces of the airflow passage within the cabinet are lined with acoustic absorption material appropriate for use in air-handling equipment, reducing the fan noise radiated back through the inlet and outlet openings into the connected ductwork and building spaces. The thermal insulation incorporated in the cabinet panels limits heat transfer from the high-temperature smoke stream to the cabinet exterior surfaces and the surrounding equipment room.
Intelligent Dual-Speed Control Panel The standard control panel supplied with the Dual Speed Fire Ventilation Fan Box manages the transition between daily ventilation and emergency smoke exhaust operating modes. During normal building operation, the panel maintains the motor in low-speed mode. On receipt of a DC24V fire alarm linkage signal from the building fire alarm control panel, the control panel automatically switches the motor to high-speed mode, initiates the high-speed exhaust cycle, and outputs a running status signal back to the fire alarm system to confirm that smoke exhaust operation has commenced. The control panel also provides manual override switching for commissioning, maintenance testing, and emergency local operation.
Multiple Discharge Angle Options The scroll housing can be configured with the discharge outlet oriented at any of up to 12 different angular positions relative to the cabinet, allowing the unit to be installed with the discharge duct connection in the direction most convenient for the ductwork layout of the specific installation without requiring field modification of the scroll housing.
Parameter | Specification |
Fan Type | Double-inlet centrifugal, cabinet enclosure |
Motor Position | External — isolated from airflow |
High-Temperature Rating | 280°C continuous operation for ≥ 60 minutes |
Motor Configuration | Dual-speed (high-speed exhaust / low-speed ventilation) |
Variable Speed Option | 25 Hz ~ 50 Hz variable frequency (optional) |
Cabinet Frame Material | Cold-formed aluminum alloy section |
Panel Construction | Double-layer steel sheet with acoustic/thermal insulation fill |
Power Supply | Three-phase 380V/50Hz |
Motor Protection Grade | IP54 |
Motor Insulation Class | Class F / Class H |
Airflow Range | 1,188 ~ 133,463 m³/h |
Full Pressure Range | 345 ~ 2,322 Pa |
Noise Level | 61 ~ 75 dB(A) depending on model |
Discharge Angle Options | Up to 12 positions |
Installation Options | Floor-mounted / Suspended |
Certification | CCCF fire protection product certification |
Explosion-Proof Option | Available (EXdIIBT4) |
Applicable Standard | GB 51251, GB 50016 |
Representative Performance Data:
Machine No. | Speed (rpm) | Airflow (m³/h) | Full Pressure (Pa) | Power (kW) | Noise dB(A) |
No.9 | 1600 | 2270 ~ 3980 | 538 ~ 573 | 0.75 ~ 1.1 | 61 ~ 63 |
No.9 | 1450 | 2050 ~ 3600 | 447 ~ 471 | 0.55 ~ 0.75 | 59 ~ 61 |
No.12 | 1250 | 4450 ~ 7970 | 631 ~ 680 | 1.5 ~ 3.0 | 64 ~ 65 |
No.15 | 960 | 7150 ~ 12530 | 622 ~ 712 | 3.0 ~ 4.0 | 65 ~ 66 |
No.18 | 900 | 9540 ~ 16720 | 676 ~ 745 | 4.0 ~ 5.5 | 68 ~ 69 |
No.20 | 900 | 13080 ~ 22940 | 830 ~ 905 | 7.5 ~ 11 | 71 ~ 72 |
No.22 | 800 | 16340 ~ 28130 | 829 ~ 915 | 7.5 ~ 11 | 73 ~ 74 |
Complete performance data for all machine numbers and speed configurations available upon request. Please contact our sales team with your smoke exhaust system design airflow, static pressure, and duct connection requirements.
The 280°C continuous operation for 60 minutes rating that defines fire smoke exhaust fan performance is not an arbitrary specification — it is a carefully calculated engineering threshold based on building fire progression modeling and the operational requirements of building evacuation.
Why 280°C The 280°C threshold corresponds to the temperature at which smoke exhaust ductwork Dampers are designed to close — the point at which continued smoke exhaust operation is no longer safe because fire itself is entering the exhaust system. Below 280°C, the exhaust system can safely continue removing smoke from the fire zone, benefiting evacuation. At 280°C, the fire protection system transitions from active exhaust to passive containment.
Why 60 Minutes The 60-minute duration represents the time required for building occupants to complete evacuation, for fire services to arrive and begin active firefighting, and for the fire to either be controlled or to progress beyond the point where mechanical smoke exhaust can contribute to life safety outcomes. Smoke exhaust equipment that fails before this 60-minute threshold would leave evacuating occupants in smoke-filled conditions before evacuation could be completed.
How the External Motor Achieves This The external motor isolation that characterizes the Centrifugal Fire Smoke Exhaust Fan is the engineering mechanism that makes 60-minute operation at 280°C achievable without special high-temperature motor specifications. While the impeller, scroll housing, and ductwork connections must be fabricated from materials capable of maintaining their structural and aerodynamic performance at 280°C, the motor operating in clean ambient air outside the smoke stream never experiences temperatures above normal ambient conditions regardless of what passes through the fan. The motor simply operates normally throughout the fire event. This design approach is more reliable and more cost-effective than attempting to build a motor capable of operating within a 280°C smoke stream.
The dual-speed operating capability of the Dual Speed Fire Ventilation Fan Box is the feature that makes the economics of combining daily ventilation and emergency smoke exhaust in a single unit compelling for building design and construction projects.
Low-Speed Daily Ventilation Mode During normal building operation, the fan runs continuously or on a scheduled cycle at low speed. At low speed, the fan delivers moderate airflow sufficient for the building's daily ventilation requirements — fresh air supply, stale air removal, temperature management — while consuming minimal energy and generating acceptably low noise levels for the occupied building environment. Low-speed operation provides all the daily ventilation function that a dedicated ventilation-only unit would provide, at full equipment reliability and with no compromise to daily ventilation performance.
High-Speed Emergency Smoke Exhaust Mode On receipt of a fire alarm signal from the building fire alarm control panel, the Centrifugal Fire Smoke Exhaust Fan control system automatically stops the low-speed motor winding, waits for the motor to reach rest, and then starts the high-speed motor winding. The fan accelerates to full high-speed operation within the required response time, delivering maximum airflow and pressure to the smoke exhaust ductwork system. This maximum-capacity exhaust mode removes smoke from the fire zone at the rate required by the smoke exhaust system design, maintaining clear evacuation routes and supporting firefighting operations for the full 60-minute rated duration.
Variable Frequency Option For installations where precise airflow control across a continuous range is required — whether for daily ventilation optimization or for staged smoke exhaust response — the variable frequency drive option allows the fan to operate at any speed between 25 Hz and 50 Hz, providing infinitely variable airflow adjustment without the stepped speed change of the dual-speed motor arrangement.
Dezhou Pengkai Air Conditioning Equipment Co., Ltd. applies comprehensive quality management to all stages of Centrifugal Fire Smoke Exhaust Fan production:
Component Incoming Inspection Aluminum alloy section extrusions, steel sheet, insulating fill material, impeller materials, motor units, belt and pulley components, and control panel components are all subject to incoming inspection against specification requirements. Motor units are tested for insulation resistance, rated current, and dual-speed switching function before entering assembly. Material and component certification documents are retained.
Impeller Fabrication and Balance Impeller blades are formed to specification and assembled onto the hub with the prescribed balance correction procedure applied to each completed assembly. Both static and dynamic balance are verified and corrected to the required grade for the high-speed operating condition, as balance requirements are more stringent at higher rotational speeds.
Scroll Housing Fabrication The scroll housing is fabricated from steel plate using mechanically controlled forming processes to achieve the dimensional accuracy required for consistent aerodynamic performance. Discharge outlet flange dimensions and angular position are verified against the specified configuration.
Cabinet Assembly Frame sections are assembled and panel infill installed with acoustic and thermal lining material secured in position. All internal airflow passage surfaces receive acoustic lining treatment. The assembled cabinet is inspected for dimensional accuracy, panel joint integrity, and internal lining installation quality before fan and motor assembly.
Control Panel Assembly and Testing Dual-speed control panels are assembled, wired, and function-tested through complete automatic switching sequences before installation in the cabinet. Signal input and output wiring connections are verified for correct fire alarm interface operation.
Final Function Test Every completed unit undergoes a full running test in both low-speed and high-speed modes, verifying smooth operation, correct current draw at both speeds, automatic switching function, and status signal output before dispatch.
280°C / 60-Minute Certified Fire Protection Performance The external motor design achieves the national standard requirement for continuous operation in 280°C smoke exhaust conditions for a minimum of 60 minutes, ensuring the smoke exhaust system remains functional throughout the complete building evacuation and initial firefighting period. CCCF fire protection product certification confirms compliance.
Dual-Function Value — One Unit, Two Roles Daily low-speed ventilation and emergency high-speed smoke exhaust are delivered from a single installed unit, reducing equipment quantity, installation space requirements, and overall building mechanical system capital cost compared to separate dedicated units for each function.
Cabinet Acoustic Treatment Reduces Noise Impact The double-layer panel construction with internal acoustic insulation reduces fan noise transmitted to the building environment, making the 280 Degree High Temperature Exhaust Fan suitable for installation in equipment rooms adjacent to occupied building spaces without requiring additional acoustic enclosures.
Automatic Fire Alarm Linkage The integrated control panel interfaces directly with the building fire alarm system, executing the automatic transition from ventilation to smoke exhaust mode without requiring operator intervention. Status signal output confirms smoke exhaust operation to the fire alarm panel and fire control room.
Multiple Discharge Angle Configurations Up to 12 scroll discharge angle options eliminate the need for complex duct transition pieces at the fan outlet, simplifying ductwork design and reducing installation labor for the duct connection from the fan to the main smoke exhaust duct run.
Explosion-Proof Configuration Available For buildings with classified hazardous areas requiring smoke exhaust — chemical plants, fuel storage facilities, solvent handling areas — an explosion-proof motor configuration is available, enabling the Centrifugal Fire Smoke Exhaust Fan to be safely specified for these applications.
Wide Airflow Range Covers All Building Scales Machine numbers covering airflow from 1,188 to 133,463 m³/h accommodate smoke exhaust system design requirements from medium-scale commercial buildings to the largest high-rise and industrial facility projects within a consistent product platform.
High-Rise Residential and Commercial Towers High-rise residential buildings, office towers, and mixed-use high-rise developments require smoke exhaust systems covering stairwells, elevator lobbies, corridors, and underground levels. The Centrifugal Fire Smoke Exhaust Fan serves as the primary mechanical exhaust unit for these systems, with machine number selection matched to the smoke exhaust zone area and design airflow requirements.
Shopping Malls and Large Retail Complexes Large retail floors, food courts, underground shopping levels, and enclosed mall corridors require smoke exhaust systems capable of handling large smoke zone areas with significant duct run lengths. The high-pressure capability of the centrifugal configuration — full pressure up to 2,322 Pa — accommodates the resistance of long duct runs in these large building footprint applications.
Underground Car Parks Multi-level underground parking structures require mechanical smoke exhaust systems for each parking level. The Dual Speed Fire Ventilation Fan Box serves the dual function of daily car park ventilation for carbon monoxide dilution at low speed and emergency smoke exhaust at high speed, eliminating the need for separate daily ventilation and smoke exhaust units in each parking level plant room.
Hospitals and Healthcare Facilities Hospital buildings require smoke exhaust systems with high reliability standards due to the limited mobility of many patients. The CCCF-certified fire protection performance and automatic fire alarm linkage of the Centrifugal Fire Smoke Exhaust Fan meet the stringent reliability requirements of healthcare building fire safety design.
Hotels and Hospitality Buildings Hotel buildings require smoke exhaust systems covering guest floor corridors, basement car parks, commercial kitchen areas, and function spaces. The acoustic treatment of the cabinet enclosure reduces noise impact on guest room areas during daily low-speed ventilation operation, while the full fire protection performance is available when needed.
Industrial Facilities and Warehouses Large factory buildings, warehouse and logistics facilities, and industrial plant buildings with significant smoke exhaust requirements are served by larger machine number configurations of the 280 Degree High Temperature Exhaust Fan, with explosion-proof options available for facilities handling flammable materials.
Tunnels and Transportation Infrastructure Road tunnels, railway station platforms, and underground transportation infrastructure require high-capacity smoke exhaust systems for fire safety. The high-airflow, high-pressure capability of larger machine number configurations is matched to the demanding requirements of transportation infrastructure smoke exhaust systems.
Our centrifugal fire smoke exhaust fan products have been supplied to fire protection and building services projects across Southeast Asia and international markets:
"We specified Pengkai centrifugal fire smoke exhaust fans for the smoke exhaust systems of a 32-floor mixed-use tower. The dual-speed units provided the required daily car park ventilation at low speed and passed fire system commissioning testing at high-speed smoke exhaust mode. The CCCF certification documentation was complete and accepted by the fire authority without queries." — Fire Protection Engineering Contractor, Southeast Asia
"For a large underground shopping complex requiring smoke exhaust fans with substantial duct run lengths, the centrifugal high-pressure capability of the Pengkai units was the deciding factor in specification. The Dual Speed Fire Ventilation Fan Box configurations delivered the required pressure at commissioning measurements. Packaging and sea freight handling were both appropriate for the equipment size." — HVAC System Integrator, Regional Project
"We have used Pengkai 280 Degree High Temperature Exhaust Fan products across several hospital projects requiring the highest fire safety reliability standards. Annual fire system inspection performance has been consistently satisfactory, and after-sales technical support for commissioning documentation and inspection reports is responsive and professional." — Building Services Consultant
Pre-Installation Checks Verify that the machine number, speed configuration, discharge angle, duct connection dimensions, and power supply specifications match the fire protection system design documents. Confirm CCCF certification documentation is present and matches the supplied unit. Inspect the cabinet, impeller, motor, control panel, and all components for transport damage. Manually rotate the impeller to confirm it turns freely.
Foundation and Mounting For floor-mounted installation, the foundation dimensions should exceed the unit base dimensions by a minimum of 100mm on each side. Anti-vibration mounts — rubber isolators or spring isolators as specified — must be installed between the unit base and foundation to prevent vibration transmission to the building structure. For suspended installation, use anti-vibration suspension hooks and verify that the suspension structure load capacity is adequate for the unit weight with an appropriate safety factor.
Soft Connections at Duct Interfaces Connect all duct work to the unit inlet and outlet flanges using flexible soft connectors — fire-rated fabric or equivalent flexible material. Soft connections prevent duct vibration from transmitting into the unit and allow for slight positional adjustment at installation. Ductwork must be independently supported and must not apply weight or bending stress to the unit flange connections.
Electrical Connection Three-phase 380V/50Hz supply connection must be performed by a qualified electrician. Verify phase sequence and supply voltage before connection. Connect fire alarm interface wiring to the control panel per the project wiring diagram. Test automatic switching function — low speed to high speed — before completing installation.
Commissioning Tests Before system commissioning, run the unit in both low-speed and high-speed modes and verify correct current draw at each speed. Test the automatic fire alarm signal switching sequence. Verify status signal output to the fire alarm panel. Measure airflow at commissioning and confirm compliance with the smoke exhaust system design requirements.
Monthly Inspection Check cabinet exterior for physical damage. Listen for abnormal noise or vibration changes during operation. Verify control panel indicator lights show correct operating status. Inspect flexible duct connectors for condition.
Quarterly Function Test Test automatic switching from low speed to high speed by simulating a fire alarm signal at the control panel. Verify high-speed current draw is within rated range. Confirm status signal output to fire alarm panel. Reset to normal low-speed ventilation mode after testing and record results.
Annual Certified Inspection Engage a qualified fire protection inspection body for annual performance verification including high-speed airflow measurement, current draw verification, high-temperature operation verification, automatic switching function test, and issuance of annual inspection report for building fire safety compliance records.
Belt and Pulley Inspection For belt-drive configurations, inspect belt condition, tension, and pulley alignment quarterly. Replace belts showing wear, cracking, or fraying before failure occurs. Verify pulley alignment and re-align if required.
Impeller Cleaning Clean impeller blades and scroll housing interior of accumulated dust annually or more frequently in dusty environments. Dust accumulation on impeller blades causes imbalance and performance reduction.
Packaging Each Centrifugal Fire Smoke Exhaust Fan unit is packaged in a robust wooden crate appropriate to the unit size and weight, with foam padding and blocking to prevent movement and contact damage during sea freight transit. For larger machine numbers, the cabinet may be partially disassembled for transport and reassembled at the installation site. Control panels and accessories are packed separately within the crate. Export-grade packaging is standard for all units.
Minimum Order Quantity We accept both single-unit orders for specific project requirements and multi-unit orders for full building supply contracts. Please contact our sales team to discuss project requirements and lead time for the specific machine numbers and configurations required.
Lead Time Standard machine numbers in common configurations are available from production scheduling with lead times confirmed at order placement. Custom configurations including non-standard discharge angles, explosion-proof motors, and special control panel specifications are produced to order.
Shipping We ship from Dezhou, Shandong Province. Sea freight is the primary mode for international orders due to unit size and weight. Air freight is available for urgent smaller units. We work with established freight forwarding partners serving Southeast Asia, the Middle East, and global destinations. FCL sea freight is recommended for multi-unit project orders.
Sample Policy For project-specific sample inspection requirements, we can supply representative units for pre-order technical evaluation. Sample arrangements including cost and shipping are agreed with buyers prior to dispatch.
Payment Terms We support T/T bank transfer and other payment arrangements as mutually agreed. Please contact our sales team for terms appropriate to your project order value and procurement process.
The Centrifugal Fire Smoke Exhaust Fan carries CCCF (China Compulsory Certification for Fire Products) certification, confirming that the product design and production processes have been verified by an accredited fire protection product certification body to comply with the national standards governing fire smoke exhaust equipment including GB 51251 and GB 50016. CCCF certification is a mandatory requirement for fire protection equipment installed in buildings in China and is recognized as a quality benchmark by fire protection engineering professionals in international markets.
Dezhou Pengkai Air Conditioning Equipment Co., Ltd. maintains production quality management covering incoming component inspection, in-process assembly quality control, impeller balance verification, control panel function testing, and completed unit running tests. Full quality documentation for each production batch is available to buyers on request. We welcome pre-shipment inspection by buyer-nominated agencies for project-specific orders.
What is a Centrifugal Fire Smoke Exhaust Fan?
A centrifugal fire smoke exhaust fan is a cabinet-enclosed mechanical ventilation unit specifically designed to serve two functions within a building's ventilation and fire safety systems: providing daily building ventilation at low speed under normal conditions, and delivering high-capacity emergency smoke exhaust at high speed during a fire event.
The centrifugal fan configuration — using a double-inlet impeller and spiral scroll housing — generates the higher static pressure required to drive smoke through the resistance of long smoke exhaust duct systems in large buildings, making it more suitable than axial fan configurations for applications where significant duct run lengths are involved.
The defining technical feature of this product category is the external motor position. By mounting the drive motor outside the main airflow passage and isolating it from the smoke stream, the design enables continuous operation in 280°C exhaust conditions for a minimum of 60 minutes — the national standard requirement for fire smoke exhaust equipment. The motor operates in clean ambient air throughout the fire event while the impeller and scroll housing handle the high-temperature smoke, achieving the required fire protection performance without requiring special high-temperature motor specifications.
The dual-speed motor configuration is the operational feature that enables the combined daily ventilation and emergency smoke exhaust function. At low speed, the unit provides quiet, energy-efficient daily ventilation. On receipt of a fire alarm signal, the integrated control panel automatically switches to high-speed operation, engaging maximum fan capacity for smoke exhaust.
The Centrifugal Fire Smoke Exhaust Fan carries CCCF fire protection product certification and complies with GB 51251 and GB 50016 national standards. It is specified for high-rise buildings, shopping malls, underground car parks, hospitals, hotels, industrial facilities, and transportation infrastructure smoke exhaust systems.
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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