The air permeability of aluminum frames provides information about the airflow that passes through our frame when it is closed, depending on the pressure exerted by the air on the frame. This value also affects the frame’s sound insulation. Thus, we have a measure of the frame’s sealing.
Categories – Classes: (lower) 1, 2, 3, 4 (higher).
At this point, it should be noted that in the tests, two values are measured for the air permeability of aluminum frames: the air permeability of the frame, which measures its total surface, and that which measures the joints. The final classification results from the comparison of these two. Thus, if a frame falls into the same class in both categories, that is its final classification. If the classes in the two categories are adjacent, the frame is assigned the more favorable class. If there is a difference of two classes, the frame is assigned the middle class.
Permeability of total surface
| Category – Class | Permeability at 100 Pa – Pascal (m3/h*m2) | Maximum test pressure (Pa – Pascal) |
|---|---|---|
| 1 | 50 | 150 |
| 2 | 27 | 300 |
| 3 | 9 | 600 |
| 4 | 3 | 600 |
Permeability of total joints
| Category – Class | Permeability at 100 Pa – Pascal (m3/h*m2) | Maximum test pressure (Pa – Pascal) |
|---|---|---|
| 1 | 50 | 150 |
| 2 | 27 | 300 |
| 3 | 9 | 600 |
| 4 | 3 | 600 |
For a complete understanding of Pressure in Pa (Pascals), we provide the Beaufort equivalences.
Beaufort – Pascal Equivalency Table (Air permeability of aluminum frames)
| 5 Beaufort Fresh breeze | 50 Pa | 29-38 km/h | Small trees sway |
| 6 Beaufort Strong breeze | 100 Pa | 39-49 km/h | Wires whistle |
| 7 Beaufort Near gale | 150 Pa | 50-61 km/h | Difficulty walking against the wind |
| 8 Beaufort Gale | 200 Pa | 62-74 km/h | Tree branches break, increased difficulty walking |
| 9 Beaufort Strong gale | 300 Pa | 75-88 km/h | Minor damage to houses and roofs |
| 10 Beaufort Storm | 450 Pa | 89-102 km/h | Trees uprooted with significant damage |
| 11 Beaufort Violent storm | 600 Pa | 103-117 km/h | Severe damage to houses |
| 12 Beaufort Hurricane | 750 Pa | > 117 km/h | Catastrophic damage to houses |
In all the above, the installation of the frame and the perimeter mechanisms play a primary role. If the aluminum frame is installed (sealed – Air permeability of aluminum frames) differently from how the frame was tested in the laboratory, or has different mechanisms and components, none of the above values apply.
How the air permeability of frames is measured
To measure a frame’s air permeability, a frame is placed in a certified test chamber, and water and air are gradually applied under pressure.
The moment the frame begins to show leaks, the process stops, and the frame is classified into the category.
See actual test
