All windows and sliding glass doors must go through basic testing that results in an AAMA classification; commonly called NAFS (North American Fenestration Standard). Local building codes reference this standard accompanied by an AAMA class (R, LC, CW, or AW) and a design pressure (50, 55, 60, etc.). The class and design pressure dictate the rating of the window according to what part of the country it goes into. Testing is meant to simulate the stresses a window or sliding glass door may go through during typical use.

Mandatory testing includes:

This test measures air leakage through the window itself. Wojan tests to AAMA 101 which has an allowable air infiltration rate of 0.30 cfm/ft². The IECC’s section C402.4.3 has a maximum or allowable rate of 0.20 cfm/ft², with the exception of the AW class which has a maximum or allowable rate of 0.30 cfm/ft².

While Wojan tests to AAMA 101, all of our products actually do meet the IECC C402.4.3 requirement for Air Infiltration, with the exception of the 2100 and 2800 patio doors, which have Air Infiltration rates of 0.21 cfm/ft².

Water resistance measures how much at least 4 gallons of water per square foot of window is resisted by the window at a given percentage of the design pressure. 15% for R, LC and CW, and 20% for AW.

Deflection measurements: The window is loaded to the design pressure and the amount of deflection at the center of the mullion is measured. For R & LC products, this is a report only measure. For CW & AW rated windows, due to the higher structural stresses that the product will encounter, there is a limit to the amount the window can deflect. It is expressed in L/175, where L is the length of the mullion.

Overload pressure: Once the first portion of structural testing is complete, overload testing to 1.5 times the design pressure is done. While deflection measurements are measured, they are report only, but the window must still stay intact without major deformation and be in working condition after testing is complete.

These test methods measure the resistance of elements of fenestration products such as operating (or removable) window sashes, storm sashes, and sash members to forces tending to deglaze the construction.

These test methods cover the ability of window assemblies of various types to restrain, delay, or frustrate forced entry. Testing procedures include:

  • Disassembly test
  • Lock hardware manipulation test
  • Sash manipulation test
  • Louver manipulation test
  • Window assembly tests based on the window type which includes applying specified loads and forces to determine whether or not entry can be gained through the window from the exterior

Life cycle testing is optional on R, LC and CW rated products, but required for all AW rated products due to the increased stresses the product will encounter.

Testing: Testing the Window for Air Infiltration, Water Penetration, Uniform Structural & Operating Force

Cycle Test including Misuse: Comprised of both use and misuse operations that are completed many, many times to simulate approximately 7 years of use in the span of a day

Thermal Cycling: Cycles of extreme temperatures ranging from 0° to 180° F

Uniform Structural @ Design Pressure

Re-Testing: Repeat Air Infiltration, Water Penetration & Operating Force: Windows must pass the criteria accomplished the first time through

Uniform Structural @ 1.5 Design Pressure

Other Performance Testing Options:

Thermal product testing covers a wide variety of criteria including:

  • U-factor: insulating value
  • Solar Heat Gain Coefficient: amount of passive heat that passes through the window
  • Condensation Resistance: value that dictates when warm moist air will condensate on a window

Due to the extremely large amount of glass options that manufacturers offer, we use industry standard simulation software to calculate these values. The validity of the computer model is verified by the actual physical test.

Just like the windows themselves, IGUs (Insulated Glass Units) are tested to insure that their hermetic seal does not become compromised causing it to fail prematurely. This is what causes condensation on the interior of the glass.

In addition to checking for the percentage of argon in the IGU, testing is comprised of three main parts:

  • High Humidity Phase: For a period of 14 days, the units are kept in an environment of 140 degrees F and 90-100% humidity.
  • Temperature Cycling Phase: The temperature alternates between -20 F and 140 F twice a day over a period of 63 days. In addition to high temperatures, during the “hot” cycle, the IGU is exposed to UV Light (Ultraviolet Light) which degrades the materials that hold the two pieces of glass together. A mist is also applied during the first hour of this cycle to add more environmental elements that degrade the IGU.
  • Frost Point: Once complete the windows are checked for “frost point” which determines whether the hermetic seal of the IGU has failed.

No one wants to be bothered inside their home or office with unnecessary sound, so windows can be tested to see how well they are at keeping sound outside where it belongs.

Sound testing is calculated based on a large spectrum of sound waves that are blasted at a window and the amount that gets to the interior of the building is expressed in two different values.

  • STC (Sound Transmission Class) is a measure of the spectrum of sound of typical conversations between people.
  • OITC (Outdoor-Indoor Transmission Class) is a measure of the spectrum of sound that is typically more disruptive, such as trains, planes, cars and trains.

Testing is comprised of two main components and is expressed as Zone Number, Missile Type and design pressure. The intent of this testing is to simulate debris hitting a window during a storm. During a hurricane, the atmospheric pressures inside and outside the home can vary greatly. Since nature wants all pressures to be equal, if a large window is impacted and the entire piece of glass is removed from the opening, a very rapid pressure equalization can occur which can cause major structural damage to the building envelope, sometimes to the point of failure.

The two main components of Hurricane Impact testing are:

  • Impact: A “missile”, which could be a 2×4 or steel ball bearings, is sent toward a window at varying speeds. Multiple “missiles” impact various parts of the window. The zone number and missile type typical for the geographic location and building type dictates the type of missile used for testing and where it impacts the product.
  • Cycling: After being impacted, the window or door is then cycled thousands of times in both the inward and outward directions. During this cycling certain breakdowns, such as deglazing and tearing, must only occur within a specific range.

Provisions for windows to be blast-resistant or blast-mitigating are critical to military, governmental and other buildings that could be targets of deliberate bombings, or for buildings of manufacturers that may see an accidental blast event.

A blast shockwave can either be simulated with an air blast test or can be recreated using a live field arena test using the actual explosives that the window is designed to resist. Once the shockwave encounters the window, debris may fly into the building that could cause injury. The blast-mitigating window system is designed to resist this result by having special laminated glass and highly engineered anchorage of the window to the window opening to keep the window itself from becoming one large piece of debris that could cause injury.