GJB2805-2021 "Technical Requirements for Anti-Theft in Ordnance Warehouses" specifies the following specific requirements for ventilation windows:

Performance Requirements

• Airtightness Performance: The airtightness must meet the Grade 8 requirement of the GB/T7106-2019 standard, meaning that under a pressure of 10Pa, the air infiltration per unit area should be ≤0.5m3/(m2·h).

• Anti-Theft Performance: The anti-theft grade should be Level 1, with an overall resistance to destruction of no less than 25 minutes.

Materials and Structure

• Door Frame and Door Leaf: The door frame is typically made of 10mm thick steel plate, while the door leaf is made of 4mm or 5mm thick steel plate. Some internal structures may adopt a composite approach, such as 5mm + fireproof, explosion-proof, thermal insulation layer + 2mm steel.

• Rodent-Proof Mesh: Generally, 10x10x1.5mm galvanized steel mesh or stainless steel mesh profiles are used.

• Grille Design: If the ventilation window has grilles, they should be made of 16x16mm square steel profiles, with individual cell dimensions not exceeding 250x60mm or 120x130mm, and welded using a staggered vertical-long and horizontal-short equal division method.

Ventilation and Sealing Functions

• Ventilation Structure: Ventilation windows can be designed in forms such as adjustable louvers, with blades inclined at 45°. A stainless steel insect screen is installed internally. When closed, the louvers are driven shut manually or electrically, combined with sealing strips to achieve complete airtightness.

• Airtight Design: The sealing structure can adopt a multi-layer sealing system, such as double or triple sealing strips, placed at the contact surfaces between the door frame and door leaf, and at the edges of movable components of the ventilation opening, forming a環(huán)形密封腔 (annular sealing cavity) to ensure no air infiltration when closed. The edges of the door leaf can be machined with grooves to embed elastic sealing strips,配合門框的凸臺設計 (coordinating with the boss design of the door frame) to form a "mortise-and-tenon" type seal, enhancing the airtightness grade.

Locking and Fixing

• Bolt Requirements: Use ?25 Q235 round steel profiles with a cross-sectional area of no less than 490mm2 and an effective extension length of no less than 30mm. The bolt should function in three directions: top, bottom, and opening side. A lockable bolt should be installed on the inner side of the door.

• Padlock Requirements: The door padlock should be placed in a concealed location on the inner side of the door. Locking and unlocking are performed through a lock hole on the ventilation window. The lock hole尺寸應不大于 100mmx150mm (dimensions should not exceed 100mmx150mm), with the nearest distance to the padlock center being no less than 250mm, and a lockable small door should be installed. Within a 200mm radius centered on the padlock, an additional protective steel plate with a thickness of no less than 3mm should be installed.

Installation Requirements

• Fixing Method: The ventilation window frame should be fixed to the wall using expansion bolts ≥12mm (spacing ≤500mm) or by welding to embedded steel plates, ensuring a secure connection between the window unit and the building structure to prevent overall disassembly.

• Sealing Treatment: Gaps between the window frame and the wall should be filled with fire-resistant sealant,兼顧氣密與防火性能 (balancing both airtightness and fire resistance).

Opening and Closing Methods

• Double-Leaf Swing Structure: Ventilation windows typically adopt a double-leaf swing structure, with one leaf secured by a lockable bolt on the inner side. This structure facilitates opening and closing while providing good anti-theft and protective performance.

• Single-Leaf Door Structure: In certain specific cases, ventilation windows can also adopt a single-leaf door structure. This structure is simple, easy to install and maintain, but its anti-theft and protective performance is relatively weaker.

Price

The price of ventilation windows varies depending on the brand and configuration, typically ranging from 1700 RMB / square meter to 2350 RMB / square meter.