Pub. 2 2021-2022 Issue 1

28 REFLEXION | 2021-22 | AIA Utah How do you know what performance class is needed for a given job? Calculate the building’s minimum design pressure. Choose the PG that exceeds the minimum design pressure. What are the specific performance requirements for each class? Entry into each performance class is based on a gateway, which is the minimum set of primary requirements for that class. The gateway is expressed as the design pressure or wind load in pounds per square foot, and products for each performance class have been designed and successfully tested for that pressure. For example, the gateway for class R is 15 PSF, or PG 15. For class LC, the gateway is higher: 25 PSF, or PG 25. If a tested product does not meet the 15 PSF requirement, it cannot be labeled R. If it does not meet the 25 PSF requirement, it cannot be labeled LC, and so on. Refer to the following table for a list of performance classes, the associated PG and the other tests’ criteria. • R buildings are one- and two-family dwellings. • LC buildings are low-rise buildings that are typically multifamily, offices, professional buildings or motels. • CW buildings are low- to mid-rise buildings that include hospitality, retail, and institutional use. • AW buildings are high-rise buildings, larger institutional buildings and so on. They would include places where engineers and architects expect demanding fenestration use, such as skyscrapers or buildings that must continue functioning under emergency conditions. The performance class designations are descriptive. They are not directly related to similar designations often found in building codes. Some windows have gold-colored labels on the inside of the frame stating that they have been rated in accordance with AAMA/WDMA/CSA 101/ I.S. 2/A440-XX. What does this mean, and how do you read the AAMA Gold Label? The label’s four key components are on the bottom line of the label’s right side and are separated by hyphens. They are: 1. Performance class 2. Performance grade 3. The maximum size tested (in metric and inch-pound units) 4. The window type: H (hung), C (casement), HS (horizontal slider) and so on Is there more than one gold label type? Yes. ANSI/AAMA/NWWDA 101/I.S. 2-97 is a voluntary performance specification for aluminum, vinyl and wood-framed windows and glass doors. The specification has standards for air leakage, forced-entry resistance, structural strength and water  — continued from page 27 penetration. It also has some material and component requirements. NFRC 100 is a thermal performance standard. These gold labels were divided into three sections by two vertical bars. • The left section had the AAMA member logo. • The middle section listed the manufacturer’s code number on the bottom right side. • The right section consisted of five lines. ■ Line 2: the specification used to build the window ■ Line 3: information about the window (see below for more information) ■ Line 4: the manufacturer’s series number ■ Line 5: if necessary, any specific code compliance The third line contained the following information: • Window type: H (hung), C (casement), HS (horizontal slider) and so on • Product class: R (residential), C (commercial), LC (light commercial), HC (heavy commercial) and A (architectural) • Performance grade: 15, 20, 25, 30, 35 and so on • Maximum size tested, such as 120 x 59 How important is it to protect a home or business with windows or doors that have PG ratings? Very important, because you are shooting in the dark without them. If the PG value is too low, you risk catastrophic failure. If the PG value is too high, the window costs more than necessary. What are the best DP or PG ratings for Utah? That depends on where the building sits and how tall it is. Choose the windows that are appropriate for the situation. Architects don’t get into PG ratings for residential homes, but PG ratings are very important for multifamily homes. I use the same program architects use to define PG ratings. Class Minimum PG Minimum Design Pressure (PSF) Structural Test Pressure (PSF) Water Resistance Test Pressure (PSF) Required Percentage for Water Testing R 15 15.0 22.5 2.9 Not applicable LC 25 25.0 37.5 3.8 15% CW 30 30.0 45.0 4.5 15% AW 40 40.0 60.0 8.0 20%