Section 1: Product Overview

The Pressurization Air Supply Vent is a specialized fire protection component that forms the terminal delivery point of a building's mechanical pressurization smoke prevention system. While smoke exhaust components work to remove smoke from fire zones, the pressurization system works from the opposite direction — actively supplying fresh air into evacuation zones to create a higher air pressure than the surrounding fire-affected spaces. This pressure difference generates a continuous outward airflow at every gap, door frame, and opening in the protected zone boundary, physically preventing smoke from entering the evacuation pathway.

The effectiveness of this smoke prevention strategy depends entirely on maintaining the correct pressure differential at all times during a fire event. The national standard specifies a minimum pressure differential of 40 to 50 Pa in pressurized stairwells and 25 to 30 Pa in pressurized lobby ante-rooms. Achieving and maintaining these values requires a correctly designed pressurization fan system working in combination with properly functioning Pressurization Air Supply Vent units at each floor level.

The normally closed configuration of the standard Pressurization Air Supply Vent is critical to system performance. If vents were open at all floors simultaneously during a fire event, the pressurization fan would be unable to maintain the required pressure differential at the affected floors, as fan capacity would be divided across too many open outlets. The normally closed design ensures that only the vents at the fire floor and immediately adjacent floors open during a fire event, concentrating fan output where it is needed and enabling the pressure differential specification to be achieved and sustained throughout the evacuation period.

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 pressurization vent products to HVAC engineering contractors, fire protection consultants, building developers, and construction procurement teams across domestic and international markets. All products are manufactured in compliance with national fire protection standards and are available in multiple configurations and sizes to match the full range of building project requirements.

Section 2: Product Types and Configuration Guide

Two primary configurations of the Pressurization Air Supply Vent are available, each matched to specific installation zone requirements defined by national fire protection design codes.

Type 1: Normally Closed Pressurization Air Supply Vent This is the standard configuration for installation in lobby ante-rooms, combined ante-rooms, fire elevator ante-rooms, and refuge floors. In daily operation, the vent blades are held in the fully closed position by the actuator mechanism, minimizing air leakage from the pressurization duct system. During a fire event, the fire alarm linkage system opens only the vents at the fire-affected floor and the floors immediately above and below, concentrating pressurization fan output at the critical zones. The normally closed design achieves the zone-selective pressurization required by national codes for ante-room applications.

Key operational characteristics:

· Daily state: fully closed, sealed, no air supply

· Fire activation: opens on DC24V signal or manual operation

· Closes: by manual reset after fire event, or automatically at 280°C fusible alloy trigger

· Zone control: only fire-floor and adjacent-floor vents open simultaneously

Type 2: Self-Gravity Louver Pressurization Air Supply Vent This configuration is the standard specification for pressurized stairwells. The louver blades hang in the closed position under their own weight when the pressurization fan is not operating. When the fan starts and pressurized air flows through the supply duct, the air pressure pushes the blades open, delivering fresh air into the stairwell. When the fan stops, the blades fall back to the closed position under gravity, without requiring any actuator or control signal. This passive open-close operation makes the self-gravity louver type ideal for stairwell applications, where the entire stairwell shaft is pressurized as a single zone and individual floor-level zone control is not required.

Key operational characteristics:

· Daily state: blades closed under gravity, no air supply

· Fan start: air pressure pushes blades open automatically

· Fan stop: blades close under gravity automatically

· No actuator, no control wiring, no manual reset required

Section 3: Product Structure and Key Components

Valve Body Frame The outer frame is fabricated from cold-rolled steel or stainless steel with corrosion-resistant surface treatment. It is designed for wall-surface mounting or supply duct end-connection, with flange or direct-fix mounting options. Frame dimensions are customizable to match project supply duct sizes and wall opening specifications.

Multi-Blade Linkage Assembly For normally closed models, the blade assembly consists of linked metal blades that operate in synchronized open and close movement. In the closed position, blades seal against the frame contact surface, supported by high-precision sealing components that minimize daily air leakage. In the open position, blades pivot to allow maximum airflow into the pressurized zone. For self-gravity louver models, individual blades hang independently on pivot shafts, falling closed under gravity when no airflow is present and opening individually under air pressure when the fan operates.

DC24V Electric Actuator — Normally Closed Models The electric actuator receives DC24V fire alarm linkage signals and drives the blade assembly to the fully open position. The actuator also supports manual override operation for commissioning, fire drills, and maintenance testing. Signal feedback output reports open and closed blade status to the fire control room in real time.

Manual Operation Device A clearly marked manual operation lever or pull-cord is provided on the accessible face of the normally closed vent. This enables on-site emergency activation when the automatic linkage system is unavailable, and is also used for commissioning and semi-annual maintenance tests.

280°C Fusible Alloy Element A 280°C fusible alloy element is installed within the supply airflow path. If supply duct temperatures reach 280°C — indicating that fire has entered the supply ductwork — the alloy melts and triggers automatic blade closure, preventing flames from being delivered into the pressurized evacuation zone through the supply vent. This is a one-time trigger requiring element replacement before the vent can be reset.

High-Precision Sealing Components For normally closed models, sealing strips or gaskets are fitted along blade edges and frame contact surfaces. These maintain low daily air leakage from the pressurization duct system when the vent is in its closed standby state, contributing to system Energy Efficiency and pressure stability.

Decorative Front Grille A decorative grille or louvered face plate is fitted to the wall-facing surface of the vent. This integrates the unit cleanly with building interior wall finishes, concealing the blade assembly and actuator components while maintaining unobstructed airflow when the vent is open.

Section 4: Technical Specifications

Please contact our sales team with your project zone type, supply duct dimensions, and pressure differential requirements for model and size selection guidance.

Section 5: The Pressurization Principle — How Smoke Prevention Works

Understanding why the Pressurization Air Supply Vent is effective requires understanding the fundamental physics of smoke movement in buildings during a fire event.

Smoke moves through buildings by following air pressure gradients — from higher pressure zones to lower pressure zones, through every available gap, opening, and unsealed penetration. In a fire zone, heat causes air to expand and pressure to rise locally, pushing smoke outward through corridors, stairwell doors, and duct openings into adjacent spaces. Without intervention, smoke can fill evacuation stairwells within minutes of a fire starting, making evacuation impossible and blocking firefighter access.

The pressurization smoke prevention strategy counters this by using the Fire Stairwell Pressurization Damper and supply fan system to raise the air pressure in stairwells and ante-rooms above the pressure in the fire zone. When the protected zone pressure exceeds the fire zone pressure by the required differential, air flows outward through every gap and opening in the protected zone boundary, physically blocking smoke from entering.

The 40 to 50 Pa differential required in pressurized stairwells is carefully balanced. It must be high enough to block smoke migration at all realistic leakage paths around closed stairwell doors, but low enough that building occupants can physically push open stairwell doors to enter or exit the stairwell during evacuation. Excessively high pressurization can make stairwell doors impossible to open, trapping occupants rather than protecting them.

The DC24V Smoke Prevention Supply Vent is the component that delivers fresh pressurized air from the supply ductwork into each protected zone at the correct flow rate to achieve this pressure differential. Its normally closed design ensures that fan output is concentrated at fire-affected floors rather than distributed across the entire building height, enabling the required pressure differential to be achieved even with realistic pressurization fan capacities.

Section 6: How It Works — Operating Sequence

Daily Standby State The Pressurization Air Supply Vent remains fully closed in its standby state. The actuator holds the blade assembly sealed against the frame. Air leakage through the closed vent is minimized by the high-precision sealing components, maintaining pressurization duct system pressure stability and reducing standby energy consumption of the pressurization fan if it runs continuously at low speed for pressure maintenance.

Fire Alarm Activation — Automatic Linkage When the building fire alarm system detects a fire event and identifies the affected alarm zone, the fire alarm control panel sends DC24V activation signals to the Pressurization Air Supply Vent units at the fire floor and the floors immediately above and below. The electric actuator receives the signal and drives the blade assembly to the fully open position. Simultaneously, the pressurization fan receives a start signal and begins supplying pressurized fresh air through the supply ductwork. The open vents deliver this pressurized air into the stairwell or ante-room at each activated floor, building up the required pressure differential within the zone.

Manual Emergency Activation If the automatic linkage system is unavailable due to power failure or system fault, trained personnel can manually activate the Fire Stairwell Pressurization Damper using the on-site manual lever or pull-cord. Manual activation must be followed by manual start of the pressurization fan if fan automatic start has also failed.

High-Temperature Auto-Close — 280°C Protection If supply duct temperatures reach 280°C, the fusible alloy element triggers automatic blade closure, preventing fire from being delivered into the pressurized evacuation zone through the supply duct. This is a protective last-resort function that would only activate if the supply ductwork itself had been compromised by fire.

Post-Fire Reset After the fire event has been controlled and the pressurization fan has been stopped, the Pressurization Air Supply Vent units must be manually reset to the closed position at each activated floor. If the 280°C fusible alloy element was triggered, it must be replaced with a new element of the same specification before the vent is reset. Once reset, the vent is returned to its normal standby state and the fire alarm linkage system is re-armed.

Section 7: Manufacturing Process and Quality Control

Dezhou Pengkai Air Conditioning Equipment Co., Ltd. applies rigorous quality management throughout Pressurization Air Supply Vent production:

Material Sourcing and Incoming Inspection Cold-rolled steel sheet, stainless steel sheet, sealing components, fusible alloy elements, and DC24V actuator units are sourced from qualified suppliers. All incoming materials are inspected against specification requirements and material certification documents are retained for traceability.

CNC Frame and Blade Fabrication Frame and blade components are processed using CNC-controlled sheet metal equipment. Dimensional accuracy is critical to achieving the blade-to-frame sealing performance required for the low daily air leakage specification of the normally closed model. Tight tolerances are maintained across all standard and custom size production runs.

Blade Assembly and Sealing Installation Blade assemblies are installed in frames with pivot shafts in bearing sleeves. For normally closed models, sealing strips are fitted and verified for continuous sealed contact across the full blade perimeter in the closed position. For self-gravity louver models, blade balance and pivot friction are verified to ensure reliable gravity closure and pressure-driven opening.

Actuator Integration and Function Testing DC24V actuator units are installed, wired, and function-tested for correct open and close operation at rated supply voltage. Signal feedback output is verified at both open and closed blade positions. Manual override operation is tested for correct function.

Fusible Alloy Element Installation Each 280°C fusible alloy element is verified for correct temperature rating and installed in the specified orientation within the supply airflow path.

Final Inspection Every completed unit undergoes a full open-close cycle test, sealing gap measurement in the closed position, signal feedback verification, and dimensional inspection against approved drawings before dispatch.

Section 8: Product Features and Advantages

Targeted Zone Pressurization The normally closed design of the Pressurization Air Supply Vent enables the pressurization system to concentrate fan output at fire-affected floors only, achieving the required 25 to 50 Pa pressure differential at the critical zones rather than distributing fan capacity across the entire building height. This is the fundamental design feature that makes zone-selective pressurization smoke prevention effective in tall buildings.

Dual-Control Reliability DC24V electric actuation via the fire alarm linkage system provides automatic zone-selective opening without human intervention. Manual override capability ensures the vent can be activated on-site if the automatic system is unavailable. Both control modes are available simultaneously and independently.

Passive Operation for Stairwell Applications The self-gravity louver configuration requires no actuator, no control wiring, and no power supply for operation. Blades open under fan air pressure and close under gravity, providing completely passive smoke prevention coverage for pressurized stairwells with zero electrical system dependency.

280°C Supply Duct Fire Protection The integrated fusible alloy element provides a final layer of protection against the unlikely scenario of fire entering the pressurization supply ductwork, automatically closing the vent to prevent flame delivery into the protected zone.

Low Daily Air Leakage High-precision sealing components in the normally closed model minimize air leakage from the pressurization duct system during standby operation, reducing standby energy consumption and maintaining system pressure stability.

Clean Architectural Integration The decorative front grille integrates the DC24V Smoke Prevention Supply Vent cleanly with building interior wall finishes in hotels, offices, hospitals, and residential buildings, concealing operational components without obstructing airflow performance when the vent is activated.

Real-Time System Monitoring Signal feedback output to the fire control room provides real-time open and closed status for every vent in the pressurization system, enabling operators to verify correct zone activation and monitor system status throughout the fire event.

Section 9: Application Scenarios

The Pressurization Air Supply Vent is installed exclusively in building zones designated as mechanical pressurization smoke prevention areas under national fire protection building codes. The following are the mandatory and recommended installation locations:

Fire Stairwells — Self-Gravity Louver Type Pressurized fire stairwells in high-rise buildings require a Fire Stairwell Pressurization Damper at each floor level. The self-gravity louver type is the standard specification for this application, providing passive pressure-driven opening and gravity closure without actuator or control wiring at each floor installation point. The stairwell is pressurized as a single zone when the fan operates, with all floor-level vents opening simultaneously under fan air pressure.

Lobby Ante-Rooms and Combined Ante-Rooms — Normally Closed Type Lobby ante-rooms adjacent to fire stairwells, and combined ante-rooms serving both stairwells and fire elevators, are pressurized using normally closed Pressurization Air Supply Vent units. Zone-selective activation opens only the vents at the fire-affected floor and adjacent floors, achieving the 25 to 30 Pa ante-room pressure differential specification.

Fire Elevator Ante-Rooms — Normally Closed Type Fire elevator ante-rooms require zone-selective pressurization to protect fire elevator access for firefighting operations. Normally closed DC24V Smoke Prevention Supply Vent units are installed at each floor level, with selective activation by the fire alarm linkage system.

Refuge Floors — Normally Closed Type Refuge floors in super high-rise buildings provide temporary safe areas for building occupants unable to complete immediate evacuation. Normally closed Pressurization Air Supply Vent units supply pressurized fresh air to refuge floor areas during fire events, maintaining a smoke-free environment for occupant shelter.

Enclosed Stairwells in Underground and Low-Rise Buildings Underground car park stairwells, underground shopping center stairwells, and stairwells in low-rise buildings without natural smoke ventilation require mechanical pressurization smoke prevention. Both normally closed and self-gravity louver configurations are applicable depending on the specific design requirements.

High-Rise Residential Towers High-rise residential buildings require pressurization smoke prevention systems in stairwells, lobby ante-rooms, and fire elevator ante-rooms serving residential floors. Both configuration types are widely installed in this building category.

Commercial Office Buildings and Hotels Office towers, hotel buildings, serviced apartment buildings, and mixed-use high-rise developments require pressurization smoke prevention coverage for stairwells, ante-rooms, and refuge areas per national building codes.

Hospitals and Healthcare Facilities Hospital buildings, particularly inpatient ward towers with limited occupant mobility, require reliable pressurization smoke prevention in stairwells and ante-rooms. Normally closed Pressurization Air Supply Vent units with robust actuator reliability and easy maintenance access are preferred for healthcare applications.

Large Public Assembly Buildings Shopping centers, transport terminals, sports facilities, and entertainment venues with mechanical pressurization smoke prevention requirements in stairwells and designated refuge areas require Fire Stairwell Pressurization Damper installations at all specified locations.

Section 10: Customer Application Feedback

Our Pressurization Air Supply Vent products have been supplied to building projects across Southeast Asia and international markets. The following reflects representative feedback:

"We specified Pengkai pressurization vents for a 45-floor residential tower project. The normally closed units at ante-room floors and self-gravity louver units at stairwell floors performed correctly during fire system commissioning. Pressure differential measurements at all tested floors met the national standard requirements. The technical support from Pengkai during specification selection was helpful." — Fire Protection Engineering Contractor, Southeast Asia

"For a large hospital project requiring pressurization smoke prevention on multiple stairwells and ante-room systems, Pengkai supplied both vent types with consistent dimensional quality and complete certification documentation. The export packaging for sea freight was appropriate and all units arrived undamaged." — HVAC Engineering Company, Regional Project

"We have used Pengkai DC24V Smoke Prevention Supply Vent products across several hotel and commercial building projects. The actuator reliability during annual fire system inspections has been consistently good, and the after-sales support for replacement fusible alloy elements and technical queries is responsive." — Building Services Maintenance Contractor

Section 11: Installation Guidelines

Pre-Installation Checks Verify that the vent type (normally closed or self-gravity louver), size, and specifications match the project fire protection design documents. Confirm that fire protection product certification is present. Inspect the frame, blade assembly, actuator, fusible alloy element, sealing components, and manual operation device for any transport damage before beginning installation.

Installation Position Install the Pressurization Air Supply Vent at the designated wall position or supply duct end-connection point as specified in the project design. For stairwell installations, the vent is typically positioned on the stairwell wall at each floor level. For ante-room installations, the vent is positioned on the wall or ceiling of the ante-room connected to the pressurization supply duct.

Structural Fixing Fix the vent frame to the wall structure using appropriate anchoring hardware. The frame must be level and flush with the wall surface to allow the decorative front grille to seat correctly. For large-format vents, additional intermediate fixing points may be required to prevent frame deflection under operational air pressure.

Supply Duct Connection Connect the supply duct to the rear of the vent frame using fire-rated sealing at the flange connection interface. Seal any gap between the vent frame and the wall opening perimeter with approved fire-rated sealing material to prevent smoke leakage through the wall penetration during a fire event.

Electrical Connection — Normally Closed Models Route DC24V supply and signal feedback wiring in fire-rated conduit. Connect to the fire alarm linkage module per the project wiring diagram. Verify ground connection. Secure all terminal connections firmly. Test actuator operation at rated DC24V before completing electrical installation.

Manual Operation Device Verify that the manual lever or pull-cord is accessible and correctly marked with operational direction indicators. For installations in concealed locations, route pull-cords to an accessible operation point.

Commissioning Tests Before system commissioning, perform manual activation and reset tests, DC24V linkage activation and reset tests, signal feedback verification at the fire control room, and pressure differential measurement at representative floors with the fan running and vents activated. Document all commissioning test results.

Section 12: Maintenance Schedule

Monthly Inspection Inspect the vent frame, decorative grille, and blade assembly for physical damage, corrosion, and obstruction. For normally closed models, verify the vent is in the fully closed position. For self-gravity louver models, verify blades hang freely in the closed position without sticking. Check the fusible alloy element is present, undamaged, and free from coating or contamination. Inspect the manual operation device for correct function.

Semi-Annual Function Test For normally closed models, conduct manual activation and reset cycle tests and DC24V linkage activation tests. Verify signal feedback output at both open and closed positions. For self-gravity louver models, verify blades open correctly under simulated fan pressure and close under gravity when pressure is removed. Record all test results.

Annual Certified Inspection Engage a qualified fire protection inspection body for annual performance verification, pressure differential measurement with the pressurization fan operating, fusible alloy element condition assessment, and issuance of an annual inspection report for building fire safety compliance records.

Fusible Alloy Element Replacement Replace the 280°C fusible alloy element every two to three years as a scheduled maintenance item, or immediately following any fire event where thermal actuation has occurred. Use only replacement elements of the same specification.

Section 13: Packaging, Shipping, and Lead Time

Packaging Each Pressurization Air Supply Vent unit is individually packaged in protective carton packaging with foam corner and edge cushioning to prevent transport damage. Larger project orders are palletized and stretch-wrapped for container loading. 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 orders. Please contact our sales team to discuss project-specific requirements and volume pricing.

Lead Time Standard sizes in normally closed and self-gravity louver configurations are held in warehouse stock for short lead times. Custom-size orders 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. Both 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 with buyers prior to dispatch. We recommend buyers request and inspect samples before placing full project supply 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.

Section 14: Certifications and Quality Assurance

Dezhou Pengkai Air Conditioning Equipment Co., Ltd. manufactures all pressurization vent products in compliance with national fire protection building codes and standards governing mechanical pressurization smoke prevention systems. Each production batch undergoes incoming material inspection, in-process fabrication quality control, and finished product function testing before release.

Fire protection product certification documentation is available to support project fire authority submissions, building permit applications, and third-party inspection requirements. We welcome pre-shipment inspection by buyer-designated inspection agencies for project-specific orders.