Casement Window Series: What Is An 88 Casement Window?

What is an 88 casement window?

"88mm casement window" refers to a casement window that uses the broken bridge aluminum series profiles with a profile depth of approximately 88mm. Specifically:

1.What does "88" mean?

Here, the "88" usually indicates that the cross-sectional depth of the aluminum profile for the window frame or sash is approximately 88 mm. A deeper cross-section provides better structural rigidity and can accommodate a wider cavity for insulating glass, enhancing insulation, soundproofing, and wind resistance performance.

2.Broken Bridge aluminum material

The 88 series usually falls under the category of insulated aluminum (heat-insulating aluminum alloy): Polyamide insulation strips are embedded on the inner side of the aluminum profiles, separating the indoor and outdoor aluminum materials, significantly reducing heat conduction.

Combined with multi-layer insulating glass and multiple sealing strips, the entire window has excellent insulation, soundproofing and anti-condensation effects.

3.Casement Functionality

A casement window is hinged along one vertical side (left or right), allowing it to swing fully open in or out. Typical installations are “inward-opening” (the sash swings inside the room) or “outward-opening” (it swings outside).

Casements offer unobstructed ventilation (the entire sash area can open) and are generally easier to clean, since you can reach both glass faces from inside when it swings inward.

4.Key Advantages

Structural Strength & Wind Resistance: An 88 mm profile—with appropriately thick walls (commonly 1.6–2.0 mm)—resists deformation under high wind loads. This makes it suitable for large-span windows or high-rise façades.

Thermal Insulation: The combination of a deep thermal-break profile plus a ≥24 mm insulating‐glass unit (e.g., 6 mm glass + 20 mm spacer + 6 mm glass) yields excellent U-value (low heat transfer).

Sound Insulation: Three sealing gaskets (one on the outer edge of the sash, one in the middle chamber, and one on the interior edge) plus thick double-glazing can achieve noise reduction levels above 40 dB in many installations.

Security & Durability: Multi-point locking hardware (locking at top, middle, and bottom) combined with robust hinges (rated for 13–18 mm sash thickness) creates a secure, tamper-resistant assembly that also resists wear over time.

5.Typical Configuration

Profile Depth: Commonly, the frame (“outer” profile) is 80 mm deep, while the sash (“moving” profile) is 88 mm deep. Some manufacturers also offer 88 mm for both frame and sash.

Glass Unit: A popular choice is 5 mm + 18 mm + 5 mm (for a total IGU thickness of about 28 mm) or 6 mm + 20 mm + 6 mm (about 32 mm total). A low-E coating and argon fill further boost performance.

Hardware:

• Hinges: Concealed or exposed butt hinges rated for 13–18 mm sash wall thickness. They allow the sash to open 90° or more.
• Multi-Point Locking System: Typically three to five locking points actuated by a single handle; this ensures the sash seals uniformly against its frame.
• Handles: Ergonomically shaped levers in finishes such as champagne, graphite, or matte black.

Characteristics

(9) The nylon insulation strip uses a 35.3mm ultra-wide custom insulation strip, resulting in better insulation performance.

(10) 5mm + 27A + 5mm, with an extra thick hollow structure, has excellent sound insulation and heat insulation performance.

(11) The opening window sash adopts a four-seal design, breaking through the traditional three-seal design, significantly improving the insulation and sound insulation performance of the entire window.

(12) Fluorocarbon hollow aluminum strips, with an integrated bending process, prevent the oxidation of the hollow aluminum strips; optional warm edge strips are available.

(13) Molecular sieve desiccant is added to effectively prevent fogging, condensation, and frosting of the insulating glass.

(14) The middle rubber strip of the opening sash uses a full-foaming continuous bending process, with no seams at the corner, improving the waterproof performance and aesthetics of the entire window.

(15) The displacement drainage structure and equal pressure drainage principle ensure smoother drainage, avoiding the backflow of rainwater from the pressure tank during typhoons. The effect is better than the invisible drainage design.

 Performance parameter

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