Air Resistance (Factor A)
Airtightness is measured by applying 75 pascals of pressure - the equivalent of a steady 25 mph (34 kph) wind - to the outside of the window. Interior air infiltration is then measured in cubic feet per minute per foot of crack length.
| Volume of infiltration |
|
Window type |
| 0.002 cu. ft./min/joint ft. |
A3 |
OSTACO fixed, casement and awning windows |
| 0.086 cu. ft./min/joint ft. |
A3 |
OSTACO sliding and hung windows |
| 0.1 cu. ft./min/joint ft. |
A3 |
High-end |
| 0.3 cu. ft./min/joint ft. |
A2 |
Mid-range |
| 0.5 cu. ft./min/joint ft. |
A1 |
Low-end |
Water Resistance (Factor B)
Watertightness is measured by projecting the equivalent of 5 U.S. gallons of water per hour per square foot of window surface, the equivalent of 8 in. (200 mm) of rain in 1 hour. Air pressure is increased to simulate winds varying between 35 and 76 mph (57 to 123 kph). Ratings indicate the pressure attained without any interior water leakage.
| Wind pressure |
|
Window type |
| 700 pascals ? 14.6 psf |
B7 |
OSTACO fixed, casement and awning windows |
| 400 pascals ? 8.4 psf |
B4* |
OSTACO sliding and hung windows |
| 300 pascals ? 6.3 psf |
B3 |
High-end |
| 200 pascals ? 4.2 psf |
B2 |
Mid-range |
| 150 pascals ? 3.0 psf |
B1 |
Low-end |
Wind Resistance (Factor C)
This test measures the wind pressure windows can withstand without suffering breakage (structural shattering) or permanent damage (structural deformation).
| Wind velocity |
|
Window type |
| 220 mph (350 kph) |
C5 |
OSTACO ixed, casement and awning windows |
| 205 mph (330 kph) |
C5* |
OSTACO sliding and hung windows |
| 180 mph (295 kph) |
C4 |
High-end |
| 160 mph (255 kph) |
C3 |
High-end |
| 130 mph (210 kph) |
C2 |
Mid-range |
| 110 mph (180 kph) |
C1 |
Low-end |
Forced Entry
This test reproduces the efforts of a well-equipped individual attempting to force entry. The test has three phases. Testers try to force open the window using tools like a knife blade, screwdriver and wire. They then attach a cable to strategic points on the window and apply increasing loads. If the window continues to resist, they use tools again in a third attempt. Windows rated F1 have a locking system, but have not been tested for forced entry. Windows rated F2 have successfully passed the test at level 10. OSTACO windows are rated F2, level 40.
| Rating |
Level |
Window type |
| Level indicates the initial load applied to the cables: |
| F2 |
Level 40 = 300 lb. |
OSTACO |
| |
Level 30 = 250 lb. |
High-end |
| |
Level 20 = 200 lb. |
Mid-range |
| |
Level 10 = 150 lb. |
Low-end |
| F1 |
Test not required |
|
| 
