First off what is Fenestration?

The word Fenestrate has a universal meaning for an opening. This words originates from the Latin word Fenestratus, meaning: “provided with openings”

Thus Fenestration refers to the opening in the building seal, this can include… Windows, Skylights, Doors.

The standard testing in north America is NAFS | North American Fenestration standard

This is a ‘harmonized standard’ for Canada and the United States. It roots back to three older standards CSA A440 (Canadian standards Association), AAMA 101 (American Architectural Manufacturers Association) and WDMA 1.S.2 (Window and Door Manufacturers Association).

Along with a Canadian Supplement CSA A440S1-09.

NAFS includes

-windows and doors

-secondary storm products and tubular daylighting devices

– roof windows ad unit skylights

Does NOT include

-interior windows and doors

-garage doors, revolving doors, and sunrooms

-curtain walls and store fronts

– and commercial entrance systems

Testing to this Standard includes, but not limited to:

  1. Air leakage Resistance (Infiltration and Exfiltration)
  2. Water penetration Resistance
  3. Structural testing
  • Air Leakage

Positive and negative pressure difference is created across the system.

The air leakage is measured and must not exceed the maximum allowable levels for exfiltration and infiltration.

  • Water Penetration

The system is subjected to various pressure cycles while the system is sprayed with water then observed for any water penetration

  • Structural

A high positive or negative pressure difference is created across the system for Design Pressure (DP) and Structural Test Pressure (STP) tests.

All results must not exceed the applicable limits of the standard or the system will fail.

  • Uniform Load Deflection
  • Positive & Negative Design Pressure
  • Uniform Load Structural
  • Forced-entry Resistance
  • Stabilizing Arm Load
  • Horizontal Concentrated Load
  • Vertical Concentrated Load
  • Thermoplastic Corner Weld

Providing the client with a performance class (R, LC, CW, AW) and Performance Grade (PG) for fenestration products

These classes give an indication of performance with general suggestions for different building types given in the standard

R-residential: One and two family dwellings

LC-low common: Low-rise and mid-rise multi-family dwellings

CW-commercial window: Low-rise and mid-rise buildings with higher loadings and heavy us

AW-architectural window: High-rise and mid-rise buildings with larger size and extreme use of the products

Performance Grade – PG

The lowest value is PG15, this goes up by multiples of 5 reaching a maximum of 100 for all classes except for AW for there is no limit for the PG.

This covers all the physical testing that needs to be done to the window but how do we find out how energy efficient the window is?

Thermal modeling is them applied. Thermal modeling is commonly done by using computer simulation program that displays how a system will function thermally. It complies with, CSA-A440.2 – 2019 and NFRC 100 – 2017.

“Therm” and “Window”, developed by LBNL and NFRC (these are the software’s that are used, can we have them on the computer screen? *just a thought*)

Thermal modeling will provide you with:

  • Overall coefficient of heat transfer (U-factor)-The U-value is the mean value that will determine how energy efficient the window is
  • Solar Heat Gain Coefficient (SHGC)- this value can be seen as free energy for it determines the heat that will come in through the window and will stay in. this is great for winters but can be a problem come hot summers
  • Visible Transmittance (VT)
  • Energy Rating – requirement from CSA A440.2
  • Condensation Resistance – requirement from NFRC 100

One of the most important values from this test is the U-Factor for this value indicates how energy efficient the door or window is. Typically, the lower the U-value is, the higher level of insulation it has.

How to prep your window for physical testing?

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