Poor sound insulation, air leakage? Discover how to select doors and windows based on five key performance criteria.

Thermal insulation coefficient
K value is also called heat transfer coefficient, formerly known as total heat transfer coefficient. The current national standards and specifications uniformly name it as heat transfer coefficient (also known as K value). The thermal insulation of doors and windows refers to the ability to block heat conduction from the high temperature side to the low temperature side under the condition of air temperature difference between the inside and outside of the window. Most areas should be within the range of 1.5~2.8W (square meter·k).

Wind pressure resistance level
Wind pressure resistance performance refers to the ability of closed external (door) windows to withstand strong wind pressure. Wind pressure resistance performance is divided into 9 levels in total. The higher the level, the stronger the wind pressure resistance. Windows with wind pressure resistance level 9 can withstand wind pressure of more than 5000pa. They are generally used in glass curtain walls or high-rise buildings and can withstand very destructive hurricanes.

Sound insulation level

The sound insulation performance of doors and windows refers to the ability of doors and windows to weaken the sound of outdoor sound when entering the room. The airborne sound insulation performance of doors and windows can be categorized into 6 levels, the larger the level, the better the sound insulation performance. If you are often affected by traffic or construction noise, it is recommended to choose grade 4 and above, which can effectively isolate 35-40dB of noise.

Watertightness

Windows exhibit 6 different levels of performance regarding rainwater penetration protection when both wind and rain are present. When windows maintain good water tightness they stop rainwater from reaching the interior through window gaps or frames thus preserving dry walls and floors which leads to a better indoor environment.

Airtightness

Airtightness reflects the ability of a window to prevent air from entering or leaving a room when it is closed. It ranges from 1 to 8, with the higher the level, the lower the heat loss. A good airtightness can effectively stop cold air infiltration and reduce indoor temperature loss, thus reducing the cost of running air conditioning in our daily life. Together they determine sealing performance, which is critical for insulation, noise reduction and durability.