The invisible guardian of quiet life: revealing the five core performances of soundproof windows

Soundproof windows – more than just a “quiet” architectural barrier

When residents along Yexin Highway in Fengjing Town were repeatedly awakened by freight noise, a soundproof window reduced the nighttime noise level from 70dB to 30dB (library-level quiet). Modern soundproof windows have evolved into a comprehensive solution that combines "silence, energy saving, and safety." Their five key performance attributes- sound insulation, wind resistance, water tightness, air tightness, and thermal insulation -work together to redefine building comfort.

Sound insulation: acoustic barrier that isolates noise

Definition and Core Values

Sound insulation measures how well doors and windows reduce the transmission of sound waves. The core metric is the Sound Transmission Class (STC) . Ordinary windows have an STC of approximately 25dB, while high-performance windows can reach 35-45dB. A World Health Organization study shows that prolonged exposure to ambient noise levels exceeding 60dB can increase insomnia by 40%. High-performance windows can reduce street noise to below 35dB.

Technical indicators and influencing factors

• STC and OITC : STC is suitable for medium and high frequencies (conversation sounds), OITC is for low frequencies (traffic/subway), and it is recommended to choose OITC ≥ 35dB products for street-facing residences.

• Glass configuration : Double/triple layer tempered glass is optional, vacuum glass blocks sound waves through the vacuum layer, laminated glass (PVB film) absorbs low-frequency vibrations, and the three-glass two-cavity design can achieve full-band sound insulation.

Sanyuan environmental ventilation and sound insulation windows

Wind resistance: the cornerstone of safety for high-rise buildings

Definition and classification standards

Wind resistance measures the ability of doors and windows to resist deformation due to wind pressure. The national standard categorizes these doors and windows into 9 levels, with Level 9 (≥5000Pa) capable of withstanding a Category 12 hurricane. High-rise buildings require products with a Level 7 or higher rating, while coastal areas recommend Level 9 with a typhoon-resistant locking system.

Key technologies

• Profile structure : Multi-cavity thermally-insulated aluminum profile (wall thickness ≥1.8mm) improves rigidity, and strengthens the center stile design to control deflection ≤L/200.

• Hardware system : 304 stainless steel hinges + anti-fall devices to ensure that the window sash does not fall off under strong winds.

Watertightness and airtightness: a double barrier for waterproofing and energy saving

Watertightness

• Grading : Level 6 (≥600Pa) can withstand 500L/(㎡·h) rainstorms and is a mandatory choice in rainy areas in the south.

• Design highlights : Hidden drainage trough + EPDM rubber strip (50 years of aging resistance) + weather-resistant glue sealing to form a waterproof system.

Airtightness

• Energy saving : Level 8 airtight windows (q1≤0.5m³/(m·h)) save 1,500 yuan in electricity bills per year compared to level 5 windows, while reducing sound leakage through gaps by 3-5dB.

Thermal insulation: the core of warm in winter and cool in summer

The heat transfer coefficient (K) is a key indicator. Recommended values in northern China are K ≤ 1.8 W/(m2·K) for vacuum glass and K ≤ 2.8 for double-glazed insulated windows in southern China. Low-E coated glass filters 90% of UV rays, and when combined with multi-cavity profiles, it improves indoor temperature differences by 4-6°C in winter compared to traditional windows.

Sanyuan Environmental Engineering Cases and Purchase Guide

Typical Cases

Overview of Lanzhou Railway Noise Control

• Lanzhou Railway Noise Control : Using vacuum composite glass (sound insulation 45dB), indoor noise is reduced from 93dB to 35dB.

Overview of traffic noise control in Panyu, Guangzhou

• Traffic noise control in Panyu, Guangzhou : laminated insulating glass + level 9 wind-resistant profiles + ventilators, meeting the three major functions of ventilation + sound insulation + haze removal , and simultaneously solving noise and high-rise safety problems.

Purchase points

1. Select according to needs : For street-facing buildings, choose sound insulation ≥ 40dB, high-rise wind resistance ≥ level 7, and thermal insulation K ≤ 1.8 in the north.

2. Guide to avoiding pitfalls : Check the test report (five properties data), avoid the "vacuum glass omnipotence theory", and pay attention to the material of the rubber strip (EPDM is better than PVC).

In the future, soundproof windows will develop towards "five-property balance". Choosing a good window is not only a need for quietness, but also a comprehensive investment in safety, energy saving and comfortable life.