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161 Product Development When sound insulation programs began in the 1980s, there were few stand-alone window or door products available to the residential renovation market that were designed to reduce noise infiltration. Working with manufacturers and acoustical consultants, individual products were combined to meet sound attenuation goals. Several manufacturers have expanded their offerings to include integrated products that meet the needs of sound insulation and pass the standards for the fenestration industry. This has provided the acoustical fenestration market with performance- enhanced acoustical window and door products that accommodate varying conditions across the country. This chapter deals primarily with residential products; however the performance rating standards discussed are the same as those used to categorize institutional-grade products used in schools and other public buildings. The standards recommended for schools and so forth may be at a higher level in the rating system in order to meet the performance needs of larger fenestra- tions. Many of the manufacturers that provide products for residential SIPs also provide products for institutional SIPs. 9.1 Design Attributes of Acoustical Products Design attributes of residential acoustical windows and doors vary from their conventional counterparts. Acoustical windows and doors are engineered using the acoustic principles of added mass, material combinations, weather seals, and sometimes additional air space configu- rations to enhance their overall acoustical performance. Despite these differences in acousti- cal design, the end product is intended to be one that homeowners recognize as residential in appearance and functionality. 9.1.1 Incorporation of Greater Mass and Decoupling As discussed in Chapter 4, the thickness, weight (mass), and decoupling of a building system contribute to its ability to reduce sound transmission. Acoustical fenestration products combine greater mass into their assemblies in several ways. Manufacturers generally increase the overall frame depth of the acoustical product. This allows for heavier frame profiles and the use of larger, multichambered extrusions that provide additional sound dampening characteristics. Some manufacturers combine various base materials that, when fabricated into a finished frame assembly, help dampen or flatten the coincidence effect while enhancing the overall STC perfor- mance curve. The coincidence effect, or critical frequency of a material, is defined as the acousti- cal frequency at which the length of the sound wave traveling through the material is equal to the length of the sound wave traveling through air. The closer the sound waves, or frequencies, are to the critical frequency, the more readily they pass through the material surface. What does this mean for acoustical window and door manufacturers? Materials used in the manufacturing C H A P T E R 9
162 Guidelines for Airport Sound Insulation Programs of acoustical window and door products have varying degrees of stiffness. The stiffness of a material or assembly of materials creates a sometimes pronounced dip in particular frequency ranges in the transmission loss graph. This is known as the coincidence effect (see Figure 9.1). Depending on the severity of the effect, this can lead to notably reduced sound dampening and lower overall STC results. Although most materials or combinations of materials have a coinci- dence dip, the goal of the window or door designer is to shift the coincidence effect up or down, out of the frequency range that can decrease STC results. This effectively flattens the coincidence effect and increases the overall sound attenuation of the window or door product. This flatten- ing can sometimes be accomplished by the use of varying frame materials, increased air spaces, and multiple glass thicknesses and glazing materials. Each manufacturer determines the best combination of materials to shift the coincidence dip to increase the sound attenuation of the product at certain critical frequencies. Wider window frames allow for the application of a primary and secondary sash system. This dual-window design provides larger air spaces between the glass surfaces and allows for the use of various glass thicknesses and glass combinations. These designs greatly reduce the sound transmission through the system. Acoustical door systems add considerable mass to the core of the door slab assembly. The weight of acoustical door assemblies varies from approximately 7.5 lbs/ft2 to 8.0 lbs/ft2 to as much as 12 lbs/ft2 to 14 lbs/ft2. The sound dampening characteristics of the door system have a direct correlation to the mass of the core assembly. Manufacturers add additional sound deaden- ing materials, many of which are listed as proprietary, to the core construction to further enhance performance. Acoustical patio door systems derive additional mass through the use of multiple layers of heavy sheet glass combined into a sealed insulated glass (SIG) unit. Heavier extrusions and reinforced frame profiles are required to support the additional weight of the glazing materi- als, adding additional sound dampening performance. 9.1.2 Material Choices Acoustical fenestration products are fabricated from a number of material choices. For win- dows, this includes extruded aluminum frames and sash incorporating a thermal barrier design, extruded vinyl profiles with welded frame and sash components, composite products incorpo- Figure 9.1. Coincidence effect. Courtesy of SCS/Larson.
Product Development 163 rating a combination of extruded aluminum profiles and extruded vinyl profiles assembled into a finished system, and wood and clad wood fenestration products designed with a secondary window or storm window applied. Acoustical entrance door systems are manufactured with steel, fiberglass, solid core wood, and wood-veneered skins over a variety of core materials to produce a wide range of STC per- formance values. Acoustical patio door systems are fabricated of thermally improved extruded aluminum profiles, extruded vinyl (PVC) materials, and wood and clad wood profiles. Although aluminum and vinyl acoustical patio doors provide high STC values as stand-alone assemblies, wood and clad wood patio door systems are currently combined with secondary storm door products to produce the required STC performance. 9.1.3 Features and Aesthetic Attributes With the many acoustical window systems that are available come a wide variety of features and aesthetic attributes that allow SIPs to closely match the appearance, operation, and materials of the windows being replaced (see Figure 9.2). Acoustical fenestration products offer many of the same features and benefits found in their conventional counterparts. For example, frames and sashes are manufactured from low-maintenance materials. Wood and clad wood frame com- ponents allow designers to match windows replaced in wood window markets and in historic structures. Operating window sashes are counterbalanced and easily removable to the interior. Some manufacturers offer tilt features that allow the sash to tilt in for cleaning and maintenance. This system helps reduce the weight the owner must support while performing routine service. Glazing options, which include high-performance glazing films, gas-filled air spaces, and tinted or reflective glass packages, provide best-fit solutions for the various geographic locations and Courtesy of SCS/Larson. Figure 9.2. Acoustical replacement window.
164 Guidelines for Airport Sound Insulation Programs climates of SIPs. Many manufacturers of acoustical products offer exterior and interior trim profiles, accessory components that provide a similar profile appearance to original windows, and solutions to installation issues encountered in the field. Acoustical entry door systems are similar in appearance to conventional swinging door sys- tems and offer product features and material finishes comparable to standard door assemblies. Features such as panel designs, assorted glass-lite configurations, and secondary door systems can be applied to achieve a visual appearance similar to the door system being replaced. Acousti- cal doors can also be prepped to receive traditional hardware and lock-set assemblies. Aluminum and vinyl acoustical patio door systems are now available as stand-alone replacement doors, alleviating the need for the application of a secondary door system. These acoustic patio doors provide the homeowner with a full-lite, single door assembly capable of providing the acousti- cal values needed to satisfy most SIP requirements. Such door systems have provided a much- needed design approach to the replacement of patio doors in markets where the application of a secondary door is not widely accepted. 9.1.4 Weather Stripping and Weather Seals Weather stripping and weather seals are important components of the acoustical design. Lim- iting the air infiltration, and therefore sound infiltration, at the perimeter seal is crucial to the overall acoustical performance of the product. Acoustical fenestration products with marginal weather seals generally experience greater deficiencies in performance, particularly with high- frequency sound waves. Acoustical fenestration products use multiple layers of weather stripping at the main frame and sash connection, along with interlocking profiles at the meeting rails. Most vertical sliding windows or hung windows, and horizontal sliding windows and doors, use a pile-type weather seal with an integrated polypropylene fin. The integrated fin helps keep the filament fibers tall, even in wet conditions. This type of weather stripping causes less friction and requires a lower operating force when used in sliding window configurations. Foam-filled compression-type weather seals are ideal for use in swing doors and projected or casement windows. Many acoustical swing door and casement window designs use compression- type weather stripping. This type of weather stripping is made up of closed-cell urethane foam encapsulated in a polyethylene or vinyl cladding; this stays extremely flexible and is UV-stabilized. The foam-filled design compensates for sealing against irregular surfaces, providing superior sound attenuation and overall sealing performance. Closed-cell urethane has excellent compres- sion recovery and set resistance. 9.1.5 Window Glazing Combinations and Air Space Glazing packages and air spaces vary based on the manufacturerâs engineered designs and fab- rication techniques. Although there is a relationship between sound attenuation and air space, it is not the only design factor to consider and is not the sole consideration in determining a productâs performance or eligibility. The air space between glazing surfaces varies depending on the acoustical window manufacturer and overall product design. In recent years, manufactur- ers have developed frame and sash assemblies made up of various base materials, which when assembled into finished fenestration products provide enhanced sound dampening characteris- tics. By increasing the productâs performance with these engineered component parts, manufac- turers have been able to reduce the overall thickness of products (making them easier to install in residential walls) while still meeting the STC performance requirements of SIPs. Product type, glass thickness, glazing materials, frame materials, weather stripping, and assembly tech- niques all contribute to the overall acoustical performance of the product. Recent independent product testing has indicated that many variations in air spaces, many under 2 in., can provide
Product Development 165 STC results of STC 40 and above. Before approving any acoustical window or door product for an SIP, it is important to conduct a thorough product review for performance and compliance with program requirements, including analysis of fabrication information, assembly materials, glazing configuration, and independent test reports from a certified lab. A. Monolithic Glass Acoustical dual-window designs offer various glazing combinations that provide a range of acoustical performance. One option is the application of single-glazed monolithic or laminated glass, glazed in both the primary and secondary sash. This system allows for the use of heavy sheet glazing materials in a non-insulated glass configuration. Considerable mass can be added to the system, while the monolithic glass sheets provide the maximum air space available between the primary and secondary sash glass surfaces. STC results vary widely depending on glass thicknesses used; performance ranges from STC 38 to STC 47. This type of glazing package, in conjunction with extruded aluminum frames, is a good application for educational and other commercial appli- cations. The use of monolithic glass in both the primary and secondary sash should be reviewed by geographic region for applicable energy code compliance. Such glazing configurations may not provide the necessary thermal performance required in all regions of the country. Thermal, reflective coatings are available for monolithic glass, but they need to be hard and non-scratchable. B. Sealed Insulated Glass The addition of a SIG unit in the prime sash, in combination with a single-glazed second- ary sash, provides a triple glazing effect. The SIG unit allows for the use of soft-coat low-E coatings, gas-filled air spaces, and tinted or reflective glass packages to enhance the windowâs thermal performance. This system allows for the use of various glass thicknesses to enhance STC performance and create multiple and varying air spaces that help reduce coincidence effects. STC results of 40 to 44 can be achieved without the use of laminated or heavy sheet glass. This type of glazing can be easily serviced and readily available to homeowners at a rea- sonable cost if and when glass replacement is required. Heavy sheet glass and laminated glass can be glazed into the system if additional sound attenuation, enhanced safety, or additional performance is required. C. Laminated Glass The use of laminated glass can enhance the sound attenuation performance of the window or door system. The most common laminated glass product used in fenestration products consists of a nominal Â¼-in. overall glass thickness, made up of two sheets of 1/8-in. annealed glass, sepa- rated by a 0.30-in. (0.76-mm) PVB interlayer. PVB is a plastic film made of polyvinyl butyral. The PVB bonds the individual pieces of glass together, creating what appears to be a single sheet of glass. This interlayer provides between 1 dB and 4 dB of sound dampening to the glass sheet, depending on material, thickness, and ambient temperature. This dampening effect has a major impact on the sound transmission properties at high frequency levels and helps to considerably dampen or flatten the coincidence effect or critical frequency. It is important to note that at lower frequencies, the PVB interlayer or laminate provides no additional sound attenuating affects verses annealed glass of the same overall thickness. At low frequencies, such as those generated by airplanes, performance is generally controlled by the weight of the glass. Laminated glass may address other issues in hurricane impact regions or locations needing additional security. Although laminated glass cracks on impact much more easily than tempered glass, the PVB interlayer helps prevent the glass from separating when broken. Laminated, tem- pered glass is available when both lamination and tempering are desired. Heavy wind-load areas or hurricane regions may use laminated glass in fenestration products to keep the glass intact after impact, helping to maintain a sealed building envelope. When using laminated glass in cold
166 Guidelines for Airport Sound Insulation Programs climates, the laminated glass should be placed to the interior or warm side of the fenestration product for optimal performance. Test criteria from ASTM E90, Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions and Elements,1 give 68Â°F to 75.2Â°F as the allowable temperature range to conduct sound transmission class testing. At this range, the PVB interlayer stays supple and provides the optimal sound attenuation per- formance. However, at lower ambient temperatures, the interlayer becomes stiff, significantly limiting its sound dampening capabilities. 9.2 Product Performance Understanding the performance requirements that industries use for manufacturing architec- tural products is critical. In order to write specifications for biddable construction documents in the public arena, federal acquisition standards require that projects provide multiple options for products to secure a competitive bid. To compare products and determine their equivalency, designers and manufacturers use performance standards. 9.2.1 Performance Testing: Air, Water, and Structural Performance testing should be completed by an independent certified lab in accordance with AAMA/WDMA/CSA 101/I.S.2/A440, North American Fenestration Standard (NAFS), Standard Specification for Windows, Doors and Unit Skylights. This test procedure will include design pressure testing, air infiltration, water resistance, structural load testing, and forced entry com- pliance testing. All products should be tested to the gateway size2 indicated by the performance test standard. Based on the geographic location of the SIP, additional testing and product certifi- cation may be required. High-velocity hurricane zones (HVHZs) will require additional impact and structural load testing and may require a production quality assurance program adminis- tered and reviewed by an approved independent third-party administrator. Windows fabricated with a primary and secondary sash assembled as a dual window must be tested and certified in compliance with the dual-window (DW) test criteria.3 Performance tests must be updated every 4 years since the tests expire 4 years after the initial test completion date. In the 1997 and 2002 editions, there were five performance classes for windows, described as R for residential, LC for light commercial, C for commercial, HC for heavy commercial, and AW for architectural. The descriptions were intended to act as a general guide in helping to determine which class was best suited for a particular application. For the 2008 edition of NAFS, the C and HC performance classifications have been eliminated. A new CW classification has been added, which reduces the total number of performance clas- sifications to four. Entry-level (gateway) performance grades are: â¢ 15 lbs/ft2 (720 Pa) for R class (commonly used in one- and two-family dwellings), â¢ 25 lbs/ft2 (1200 Pa) for LC class (commonly used for low- and mid-rise multifamily dwellings and other buildings where larger sizes and higher loading requirements are expected), â¢ 30 lbs/ft2 (1,440 Pa) for the new CW class (commonly used in low- and mid-rise buildings where larger sizes, higher loading requirements, limits on deflection, and heavier use are expected), and 1 ASTM International, ASTM E90, Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Build- ing Partitions and Elements. 2 Each AAMA window performance class requires that the window sample submitted for testing be a minimum defined size that is different for each class. 3 AAMA/WDMA/CSA101/I.S.2/A440, Dual Window (DW) Test Standard.
Product Development 167 â¢ 40 lbs/ft2 (1,920 Pa) for the AW class (commonly used in high-rise and mid-rise buildings to meet increased loading requirements and limits on deflection, and in buildings where fre- quent and extreme use of the fenestration products is expected).4 9.2.2 Acoustical Performance Acoustical performance testing should be completed by a lab certified by NVLAP and in con- formance with ASTM E90 test procedures. STC values should be obtained by applying the TL values to the STC contour of ASTM E413, Determination of Sound Transmission Class. OITC performance testing should follow ASTM E1332 standards, and the transmission loss data used to determine the A-weighted sound level reduction. All fenestration products must be fully assembled, operational, and tested as a complete unit. Component part testing, such as only glass or only door slab components, is not permitted. Currently, acoustical tests do not have an expiration date. In that regard, it is important for specifications used in SIPs to establish retesting or updated testing criteria. As a baseline, retesting or updated testing should occur at a minimum of every 10 years and whenever a manufacturer makes changes to the product. 9.2.3 Test Data: STC Versus OITC Sound transmission through a window or door is measured in an acoustical laboratory made up of two reverberation chambers. The rooms are divided by a separation wall designed to elimi- nate sound transfer between the two rooms or chambers. An opening is prepared in the separa- tion wall, and the window or door is installed into the opening. When completely installed, the only sound that can travel from one chamber to the other is the sound that passes through the installed test sample. A sound source, placed in one of the reverberation chambers, injects high- level broadband noise into the chamber. Sound pressure levels are measured in both chambers simultaneously. The measured difference in the sound pressure levels between the chambers is calculated as the sound TL and is expressed in decibels. During the test, the TL values are mea- sured in frequency bands between 80 Hz to 4000 Hz. These values are then used to calculate a single-number rating for the performance of the window or door assembly. Two single-number rating systems are available to measure TL values. The first and most widely used is the STC rating. STC was originally designed to measure the performance of inte- rior partition walls, but its use has been expanded to cover virtually all types of products used to separate noise events. The STC rating is a single-number rating generated from 16 TL values between 125 Hz and 4000 Hz. The STC curve is designed to correlate with sound associated with human speech. The second single-number rating system is the OITC. The OITC has a differ- ent frequency range than the STC rating and places more significance on low-frequency sound, which relates more closely to aircraft noise. The OITC rating is the A-weighted sound level differ- ence between exterior traffic noise and the resulting interior noise. The definition of A-weighted sound level, in simple terms, is the standard measure of the sound pressure level that approxi- mates the sensitivity of the human ear at moderate sound levels. Therefore, the A-weighted sound level places less emphasis on high and low frequencies because the human ear poorly perceives these noise levels. Consequently, the OITC sound metric has a different frequency range and weighting than the STC rating, with a greater emphasis on lower-frequency sound. This is important because the STC rating is the most common metric used by manufacturers to rate the noise-reducing performance of their products. However, products that have a higher STC rating may perform marginally at some important lower frequencies. There may also be 4 Performance Class Overview, American Architectural Manufacturers Association, accessed January 2012, http://www. aamanet.org/general/1/407/performance-class-overview.
168 Guidelines for Airport Sound Insulation Programs instances where a product performs better at lower frequencies, reflecting a better OITC value, but has a lower STC performance rating. When reviewing sound performance data, it is impor- tant to review the TL values to establish at what frequencies the product is providing its best sound attenuating performance. 9.2.4 Thermal Performance Thermal performance is becoming an increasingly important issue within SIPs because many cities and municipalities have adopted new or updated energy standards within their building code requirements. Energy codes vary substantially by geographic region and must be reviewed by region to establish code compliance criteria. It is important to review the thermal perfor- mance requirements on a routine basis to ensure compliance with routinely changing codes. All fenestration products must be independently tested for thermal performance and compliance. Thermal performance testing should be conducted in compliance with current NFRC or AAMA 1503 standards (see Figure 9.3). Select a single test method so that all fenestration products of a given material type may be reviewed under the same test criteria. It is important to note that the condensation resistance (CR) rating established by the NFRC test standard is not equivalent to the condensation resistance factor (CRF) as determined by the AAMA 1503 standard. As the Minnesota Sustainable Housing Initiative states: The differences between the CR and CRF ratings are significant, though their goals are the same. The primary method of determining the CR rating is through simulation, while the CRF is based on measured data. Both should be used primarily as comparative evaluations between windows. Since there is no cur- rent data available to compare CR and CRF ratings, determining whether a CRF rated window performs better than a CR rated window, or vice versa, is difficult.5 Thermal performance tests must be updated every 4 years since the tests expire 4 years after the initial test completion date. Courtesy NFRC. Figure 9.3. NFRC product label. 5 Information Brief â Condensation Resistance, Window, Minnesota Sustainable Housing Initiative, accessed January 2012, www.mnshi.umn.edu. http://www.mnshi.umn.edu/kb/scale/condensationresistance.html.
Product Development 169 9.3 Product Durability Product durability refers to the quality and life expectancy of fenestration products used in SIPs. Specifying long-lasting and consistently functioning products is an important part of the product procurement process. Most programs want to provide participants with long-term product warranties that can only be secured for good quality products. The commitment of the manufacturer to its sound insulation products and the length of time it has been in business may be quality factors to consider as well when choosing products to specify. Review of the longevity and reliability of the window and door products can be accomplished through the component parts, such as weather stripping, hardware, sash balance systems, base material, joint construction, and glazing materials, all of which should be evaluated for their long-term performance and the ability of the building owner or homeowner to reasonably acquire and replace them. Many acoustical fenestration products use heavy sheet or laminated glazing materials; review should include heavyweight balances to support additional weight and structural loads placed on the product and the ability of the product to perform over time. Economic concerns of maintaining or replacing the glass and glazing components in the future should also be considered. Expensive glass used to achieve the noise reduction may be hard for homeowners to replace if broken. 9.3.1 ACRP Project 02-31, âAssessment of Sound Insulation Treatmentsâ At the time of the publication of these guidelines, the Airport Cooperative Research Program began ACRP Project 02-31, âAssessment of Sound Insulation Treatments,â to conduct research and provide evaluation of the performance of acoustical products and treatments in previous SIPs, including the proper maintenance required to ensure the longevity of the acoustical treat- ments provided. It is recommended that users of these guidelines review the results and recom- mendations of ACRP Project 02-31 for further information regarding sustainable and effective noise reduction products and treatment strategies. 9.3.2 Role of the Building Owner As part of the product sustainability function, it is important for SIPs to properly define the role that the building owner plays in the proper maintenance, service, and care required to ensure product performance and longevity. Most manufacturers provide care and mainte- nance manuals designed to inform building owners on how to properly care for the acoustical products they receive. Failure to properly maintain these products will generally reduce the productsâ useful lives and may void the manufacturerâs warranty. Once the contractorâs war- ranty has elapsed, building owners will be communicating with manufacturers for extended warranty service. 9.4 Specifications of Acoustical Products 9.4.1 Replacement Windows Acoustical window systems are manufactured with a variety of assembly methods and materials providing a wide range of STC performance results. However, no matter which system a program uses, the final performance of the product depends greatly on careful installation. Most acoustical windows are built with close tolerances and require extra effort during installation to ensure that noise does not enter the building by flanking the window
170 Guidelines for Airport Sound Insulation Programs unit. Also the units must be square to ensure that the designed seals and gaskets perform. Properly preparing the opening to receive the acoustical window is a critical step in the pro- cess to ensure the performance of the acoustical treatment. Acoustical windows are designed in several different ways. A. Aluminum Acoustical Dual Window The aluminum four-track acoustical window system is available in double-hung, slider, and fixed-lite configurations. Overall frame depths vary from 4Â½ in. to over 9 in. The main frame is in two sections joined by a nonâheat-conducting thermal barrier system creating a frame that can provide an inner and outer window (see Figure 9.4). Several thermal barrier systems are available and vary by manufacturer. They include extruded PVC, glass-reinforced nylon or polyamide, and poured and de-bridged polyurethane. The thermal barrier creates an inner and outer frame, which enhances the overall thermal performance and sound attenuation of the product since the energy of heat, cold, and sound waves is diminished from outside to inside. The dual-sash system consists of two primary and two secondary sashes. Both sets of sashes are removable to the interior for cleaning and maintenance. The four-track system allows for large air spaces between the primary and secondary sashes, enhancing STC performance. Sashes are dual weather stripped and designed with interlocking meeting rails. Several glazing options are available based on performance criteria. Primary and secondary sashes can be single glazed with monolithic glass to optimize the air space between sashes. Insulated glass can be supplied in the primary sash to increase thermal performance. The glass is marine glazed into the sash Courtesy of St. Cloud Window. Figure 9.4. Aluminum 4-track acoustical window.
Product Development 171 with a flexible vinyl glazing boot. The glazing boot cushions the glass, which helps to dampen sound transmission around the glazing pocket. STC performance ratings range from STC 40 to STC 55+ based on glass configuration and overall frame depth. Thermal performance varies greatly and must be reviewed by the manufacturer. AAMA performance ratings include LC, CW, and AW performance classes, depending on manufacturer and product series. Several painted finishes are available, including organic coatings and polyvinylidene fluoride organic finishes. Options for anodized finishes are also available. B. Vinyl Acoustical Dual Window This four-track acoustical window system is similar in design to its aluminum counter- part (see Figure 9.5). The main frame and sash are assembled from extruded vinyl or PVC profiles. PVC profiles are fabricated with impact-resistant plasticizers and titanium diox- ide UV inhibitors for durability. The vinyl frame and sash profiles are multichambered for added thermal and sound dampening performance. Vinyl is not an efficient conductor of thermal energy and does not require a thermally broken frame. Frames and sash corners are fusion welded for strength and durability. Aluminum reinforcements may be placed in criti- cal profiles to provide additional stiffness. Most manufacturers offer double-hung, slider, and fixed-lite configurations. Nominal depth of the main frame is approximately 4Â½ in. Primary sashes can receive a variety of glazing packages, from single-glazed (monolithic or laminated glass) to sealed insulated glass units made up of varying glass thicknesses. Secondary inte- rior sashes are single glazed and can receive various thicknesses of monolithic or laminated Courtesy of Graham Architectural Windows. Figure 9.5. Vinyl 4-track acoustical window.
172 Guidelines for Airport Sound Insulation Programs glass as required. Both primary and secondary sashes are removable to the interior, with some manufacturers offering double-hung windows with counterbalanced tilt-in sash fea- tures for ease of cleaning. Glass is generally wet glazed with silicone, or tape glazed into the vinyl sash. Both glazing systems cushion the glass, providing additional sound dampening effects. Sashes and frames are dual weather stripped with a pile-type weather stripping and integrated polypropylene fin. STC performance ranges from STC 39 to STC 45, depending on glazing configuration and window type. Thermal performance varies and must be reviewed by the manufacturer. U-values range from 0.47 to 0.21, and NFRC CR values range from 60 to 87, depending on glazing and window type. AAMA performance designations include LC and CW, based on manufacturer. The finish or color is impregnated throughout the material, making it extremely scratch resistant. C. Composite Acoustical Dual Window Composite acoustical windows combine various window systems and materials into a com- posite acoustical window assembly (see Figure 9.6). This type of assembly offers a variety of aes- thetic and performance attributes that vary by manufacturer, with some manufacturers holding patents on their assembly systems. As with the other systems mentioned, double-hung, sliders, and fixed-lite configurations are available. Frame depth of the main frame varies from 3Â½ in. to 4Â½ in. Main frames are multichambered PVC with fusion welded corners. Some manufacturers offer an extruded aluminum sub-frame that, when combined with the vinyl mainframe, provides additional STC performance. The primary sash of the composite system is placed to the interior of the window system and is made up of extruded PVC with aluminum reinforcement of criti- cal areas. The sash is glazed with a sealed insulated glass unit which can be made up of various glass thicknesses, (including laminated glass options). Energy films and gas-filled air spaces are available to improve the windows thermal performance. The secondary exterior window system is single glazed and can receive varying glass thicknesses of up to Â¼-in. thick. This secondary window system is made from extruded aluminum profiles and is âmarineâ glazed with a flexible vinyl glazing boot for additional sound dampening performance. Primary and secondary sash are removable to the interior, with the prime sash of the double-hung windows provided with a tilt-in feature for ease of cleaning and maintenance. STC performance ranges from STC 40 to STC 46 depending on the glazing configuration. Thermal performance varies by manufactur- ers. U-values range from 0.33 to 0.19, with CR values from 68 to 80 depending on glazing and window type. AAMA performance designations include R, LC, and CW ratings depending on manufacturer and product series. All dual-window composite systems must be certified under the AAMA DW standard. Dual finishes are available, with interior finishes of integrated colored PVC, optional wood grain finishes, exterior finishes including organic (painted) finishes, and optional anodized finishes. D. Wood Prime Window with Applied Secondary Storm Window Unit Wood prime windows with applied secondary or storm windows offer an acoustical treat- ment solution to programs located in wood window markets (see Figure 9.7). This system allows for the contractor to remove all existing dry-rotted and deteriorated wood components back to the rough opening. It can also be beneficial when wood windows with lead-based paint issues are prevalent. This type of configuration has also been used in the treatment of historic structures in certain geographic regions. Many programs specify a wood window manufacturer, along with an acoustical secondary or storm window manufacturer. It is impor- tant to verify the proper mounting procedures of the secondary unit with the prime wood window manufacturer to ensure that the application does not void the product warranty. There are a few acoustical window manufacturers that currently produce the wood prime window and acoustical secondary window as a factory-assembled unit. The secondary unit should be mounted to the blind stop of the wood prime window to ensure proper sealing and
Product Development 173 weatherability. Caution should be used when mounting secondary units to the face of the wood window exterior trim, ensuring the secondary window is properly flashed to eliminate the possibility of a leak between the two units. Additionally, when attempting to mount the secondary unit to the exterior face of the wood window, it is important to verify that the sash of the secondary storm window can be removed through the prime window to the interior for cleaning and maintenance. STC performance of a conventional wood window, glazed with Â¾-in. sealed insulated glass, is STC 25 to STC 29, depending on glazing configuration and window type. Performance of the conventional wood window with an acoustical secondary storm window applied is STC 40 to STC 44. Independent structural and thermal testing should be conducted for the complete assembly. Courtesy of SCS/Larson. Figure 9.6. Composite vinyl/aluminum acoustical window.
174 Guidelines for Airport Sound Insulation Programs E. Acoustical Casement and Projected Units Acoustically rated casement and projected window products are available in aluminum, vinyl, and composite window systems (see Figure 9.8). Although these windows are fabricated from various base materials, these products have similar designs and glazing configurations. Acoustical casement and projected windows tend to use compression-type weather stripping of closed-cell urethane foam enclosed in a polyurethane cladding. This weather stripping provides a substantial, positive seal around the sash perimeter. This results in extremely low air infiltra- tion and increased sound attenuating performance. Although glazing packages vary by manu- facturer, there are only a few glazing options available. One option is to glaze the unit with a 1-in. overall sealed insulated glass unit made up of two sheets of Â¼-in. laminated glass and Â½-in. air space. The other glazing option includes a sealed insulated glass unit, usually made up of two sheets of annealed glass, with a secondary acoustical glazing panel, either applied to the operat- ing sash or installed into the screen track of the window frame. Acoustical panels installed into the screen track will require the owner or tenant to remove the acoustical secondary glazing panel for ventilation or egress. STC performance ranges from STC 34 to STC 42, depending on glazing configuration. Thermal performance varies greatly by manufacturer and fabrication materials, and must be reviewed per product for code compliance. AAMA performance des- Courtesy of SCS/Larson. Figure 9.7. Acoustical secondary storm window over wood window unit.
Product Development 175 ignations include R, LC, C, HC, and AW ratings for products. Overall frame depths vary from 25â8 in. to 3Â¾ in., depending on the product and manufacturer. Since projecting windows do not routinely open to 90 degrees, when used in emergency egress locations, they need to be specified with special extension arms. Varying hinge treatments are also available when surface- mounted or hidden hinges are desired. 9.4.2 Acoustical Sliding Glass Doors Acoustical sliding glass doors are available as a single or solo prime door unit or configured with an additional secondary or storm door unit applied. A. Acoustically Rated Sliding Glass Doors Acoustical prime patio doors are available in aluminum, vinyl, and wood frame materials. All single door units are glazed with sealed insulated glass assembled with laminated glass or heavy sheet tempered glass. STC performance results range from STC 35 to STC 38, depending on the door configuration, glazing options, and glazing air space. This system allows for the use of high-performance coatings, gas-filled air spaces, and tinted glazing options to enhance thermal performance. Some manufactures also offer high-performance acoustical sliding door systems that meet impact and HVHZ test requirements. B. Tandem Sliding Glass Door Assemblies Tandem acoustical sliding glass doors are also available from various manufactures. Tandem sliding glass doors refer to the additional application of a sliding secondary or storm door to the patio door system. Tandem door systems reach STC performance results of up to STC 47 and provide a substantial increase in overall thermal performance over the single door system. This tandem door system is most generally accepted in cold climate regions where the applica- tion of secondary or storm door products is a generally accepted practice. Warmer regions may not accept the aesthetic appearance of such a door, and those in warmer regions may gravitate toward the single door system. Courtesy of SCS/Larson. Figure 9.8. Acoustical casement unit.
176 Guidelines for Airport Sound Insulation Programs 9.4.3 Replacement Swinging Doors As referenced in previous guidelines, âdoors compete with windows for the role of the weakest link in the dwellingâs sound insulation performance. Almost all typical residential doors require modification or replacement to provide the necessary protection from aircraft noise.â6 Acousti- cally treating door openings can be achieved by treating the existing door, by installing an acous- tically rated stand-alone door system, or by combining a high-quality residential entrance door system and an acoustically rated secondary door in tandem. Acoustical entrance systems are manufactured with a variety of assembly methods and core mate- rials providing a wide range of STC performance results. However, no matter which entry door system is used in any SIP, the final performance of the assembly depends greatly on the correct instal- lation of these products. Most acoustical door systems are built with close tolerances and require extra effort during installation to ensure that the perimeter seals are uniformly seated along the full length of the door slab and that the sill condition and bottom sweep positively seal across the bottom of the unit. High-quality acoustic compression seals and corner gaskets found on acoustical door systems will provide little sound attenuation if not properly seated against the door slab. Properly preparing the opening to receive the acoustical door unit is a critical step in the process to ensure the performance of the acoustical door treatment. A. Treating Existing Doors Modifying the existing door can achieve sound deadening results if the existing door has adequate mass (greater than 8 lbs/ft2),7 is structurally sound, and fits squarely into the existing frame. If all these conditions exist, replacing the weather stripping of the existing door with heavy acoustical seals and applying a positive sealing bottom sweep and treating any sidelights may provide adequate sound attenuating performance. All penetrations through the existing doors, such as mail slots, must also be adequately blocked and sealed. If the existing doors do not fit properly or do not have adequate mass, the doors should be replaced. B. Acoustically Rated Entrance Doors Acoustically rated entrance doors, offered with galvanized steel, wood, and composite wood veneer, are a popular option currently used in many SIPâs exterior skins. As referenced in the 2005 guidelines,8 typical performance ratings range from STC 29 to STC 43. Although these doors have a similar appearance to the aforementioned residential pre-hung door systems, the internal core of the door is significantly different. The wide range of STC performance implies various engineered core materials and fabrication techniques. However, the one main attribute consistent with all acoustically rated doors is the addition of significant amounts of mass. The weight of acoustically rated doors ranges from 7.4 lbs/ft2 to 8.6 lbs/ft2 (for STC 29 to STC 38 per- formance) to as much as 12 lbs/ft2 to 14 lbs/ft2 (for doors achieving results in the STC 42 to STC 44 range). The core of an acoustical entry door is made up of a series of solid wood or composite materials for doors achieving STC 29 to STC 31 performance. Layers of cross-banded engineered wood composites are added to increase STC performance to the mid-30 range. Additional layers of sound deadening materials, many of which are proprietary, are added to the core to achieve the optimum STC performance. To support the considerable amount of weight, the rails of the door are assembled with struc- tural composite lumber. Heavy-duty ball bearing hinges are required to carry the additional weight 6 See note 1. 7 Department of the Navy, Naval Facilities Engineering Command, Guidelines for the Sound Insulation of Residences Exposed to Aircraft Operations, as referenced in FAA Advisory Circular 150/5000-9A, April 2005. 8 Department of the Navy, Naval Facilities Engineering Command, Guidelines for the Sound Insulation of Residences Exposed to Aircraft Operations, as referenced in FAA Advisory Circular 150/5000-9A, April 2005.
Product Development 177 associated with the acoustical door panels. Installation of these doors must include the inspection of the rough opening to ensure that the framing members are in solid condition. If the framing members show signs of decay or are not adequate to support the acoustical door, the opening must be modified prior to installation. Installation screws should be placed through each hinge leaf and should be of sufficient length to penetrate a minimum of 1Â½ in. into the framing members. Perim- eter seals and corner gaskets should include replaceable compression-type weather stripping made up of closed-cell urethane foam enclosed in a polyurethane cladding. Door sills should include an extruded aluminum exterior with an adjustable riser to ensure adjustability and proper fit in the field. Some manufacturers provide a spring-loaded retractable door sweep that seals against the sill when the door is closed. Out-swing doors should include a bumper sill configuration with a compression-type weather seal that seals against the surface of the door slab when closed. C. Tandem Entrance Door Assemblies The application of high-quality insulated steel and wood residential entrance doors, in combi- nation with an acoustical secondary storm door, is an economical and aesthetically popular SIP acoustical treatment strategy (see Figure 9.9). The value of this application is the conventional appearance and availability of the products used. This product combination is energy efficient and provides solid STC performance values. Insulated steel entrance doors with a typical 24-gauge steel skin and polyurethane steel core weigh in at approximately 5.2 lbs/ft2 to 5.8 lbs/ft2 and provide an STC performance rating of STC 22 to STC 27. The addition of an acoustical secondary or storm door with a minimum perfor- mance rating of STC 30 brings the values of the system to STC 40 to STC 42. Courtesy of SCS/Larson. Figure 9.9. Steel entry door with acoustical secondary.
178 Guidelines for Airport Sound Insulation Programs Several door manufacturers offer optional core materials in lieu of the polyurethane core to enhance performance. Solid wood block or engineered particleboard cores increase the weight of the door to approximately 7.0 lbs/ft2 to 7.5 lbs/ft2 and provide STC results of STC 27 to STC 29. Wood-veneered skins can be applied to the solid core materials when a solid core wood door is preferred. The application of an acoustical secondary or storm door increases the performance of the combined system to STC 42 to STC 44. The air space created between the primary door and the secondary door will vary by prod- uct manufacturer and overall wall depth of the structure (see Figure 9.10). Varying air spaces between the primary and secondary door systems will affect the overall STC performance of the assembly. STC testing should be conducted on the complete assembly consisting of both the pri- mary and secondary door to ensure that the overall STC performance is acceptable. The applica- tion of this type of door system should be reviewed by geographic region to ensure performance compatibility and homeowner acceptance. D. Door STC Tests Most entrance door systems are assembled from a variety of component parts supplied by several different manufacturers. The door distributor or the contractor in the field generally Courtesy of SCS/Larson. Figure 9.10. Insulated steel pre-hung entry door with acoustical secondary storm door.
Product Development 179 assembles these component parts into a finished or pre-hung door system. STC tests provided by an independent certified lab should include the entire door assembly, pre-hung in the frame and completely operational. It is important that the test list the component parts used in the test door assembly to ensure that the doors fabricated for the project match the test door specimen. STC tests conducted only on door slabs should not be accepted because they do not represent the performance of the complete door assembly, including the perimeter seals and threshold. If an acoustical door slab is installed in an existing frame, jamb weather stripping, sill sweeps, and sill conditions should closely match those components outlined in an independent certified test report to ensure that the component parts used closely match the tested assembly. 9.4.4 High-Velocity Hurricane Zones and Impact-Rated Acoustical Products SIPs operating in HVHZ zones face unique product design and approval issues associated with sound insulating structures within these areas. Currently, few manufacturers produce acoustical window and door products for use in these regions. However, the few that have committed to the manufacturing of these specialized products have invested heavily in the design of their products and the required product approval process. As an example, programs located in southern Florida are located in a designated HVHZ. A. HVHZ Product Testing and Certification The state of Florida requires a stringent testing and certification process for all window and door products installed in HVHZs. Mandatory testing protocols include three major test criteria, TAS (Testing Application Standard) 201, 202, and 203, with all testing conducted by an indepen- dent certified laboratory (see Figure 9.11). TAS 201 â Large Missile Impact Test. TAS 201 is the test protocol that covers procedures for con- ducting large missile impact testing. Large missile impact testing consists of impacting three vari- ous locations of the window or door assembly with wood traveling at a speed of 50 ft/s (34 mph). TAS 202 â Uniform Static Load Test. This test measures air infiltration, water penetration, and structural loading of the window or door assembly. During this test procedure, the test speci- men is subjected to severe test pressures (in some cases, in access of Â±100 lbs/ft2) to ensure the structural integrity of the assembly. TAS 203 â Cyclic Load Test. Once the TAS 201 Large Missile Impact Test is successfully com- pleted, the test specimen is then subjected to alternating positive and negative test pressures, simi- lar to hurricane conditions, for a combined duration of 9000 cycles, under test standard TAS 203. Although the glazing material can crack during these tests, no structural failure of the unit is allowed during the test procedures. Upon successful completion of the testing protocol, all assembly methods, component parts, and installation details must be cataloged and submitted to an independent professional engi- neer registered in the state of Florida for a complete product review and evaluation. Once the review is complete, the independent engineer certifies the evaluation and submits the informa- tion to the Florida Department of Business and Professional Regulation to receive final product approval. The final documents are reviewed by the Florida Building Code (FBC) department for final approval. Once approved, the FBC issues a Florida products serial number uniquely identifying the approved product and registers the product on the FBC website. Manufacturers producing approved products are also required to participate in a state-approved, indepen- dently administered quality assurance program. This program requires independent and unan- nounced inspections of the manufacturing facilities producing certified products to ensure that
180 Guidelines for Airport Sound Insulation Programs the fabrication and assembly techniques of the window or door products produced match the product information certified and registered with the state of Florida. The installation of approved products in Florida SIPs requires a building officialâs inspection of the product, installation technique, and fasteners prior to the application of any type of fin- ish trim materials. All approved products must be factory labeled with their assigned Florida product serial number. The building inspector will review the reference materials outlining the product and installation instructions and verify that the conditions listed on the documents match the product and installation. Any deviation from the approved information will be cause for the product to be rejected. B. HVHZ Window Products Because of the design loads and performance requirements associated with acoustical win- dows fabricated for these regions, products use multiple layers of heavy sheet glass with the interior glazing material made up of heavy sheet laminated glass with a 0.090 PVB interlayer. Products are available in both extruded aluminum and reinforced PVC frame and sash profiles. Current window systems incorporate a dual-window design containing a primary and second- ary sash system to enhance sound attenuation. STC performance ranges from STC 44 to STC 47. Courtesy of SCS/Larson. Figure 9.11. Successful completion of TAS 201 â Large Missile Impact Test and TAS 203 â Cyclic Load Test.
Product Development 181 C. HVHZ Door Products Impact- and acoustically rated sliding glass patio door systems are also available for use in HVHZs. Although there are currently a limited number of manufacturers to choose from, these doors are manufactured as a single or solo prime door unit with STC values of approximately STC 38. These doors are glazed with multiple layers of laminated glass and sealed into a stout insulated glass unit, with the interior laminated glass using a 0.090 SGP interlayer. Frame materi- als currently available are heavy PVC-extruded profiles with aluminum reinforcement. Heavy- duty hardware and roller assemblies are incorporated to handle the substantial weight of the overall assembly. Impact-rated French doors in tandem with a sound-rated interior French or sliding door is another option to replace sliding glass doors. Acoustically treating swinging door openings includes the application of a pre-hung entrance door in tandem with an impact-rated secondary door system. STC performance is enhanced by the air space created between the primary and secondary unit along with the additional mass and heavy sheet glazing material designed into the secondary impact-rated door system. There are stand-alone doors available to meet both the sound and impact requirements of the Florida programs, but they are limited in aesthetic options. 9.4.5 Additional Products Available A. Acoustical Secondary Window and Door Systems Secondary or storm windows and doors are an important acoustical treatment option for most SIPs across the country. Secondary acoustical window and door products provide an eco- nomical solution for the acoustical treatment of existing prime window and door openings. Specialty shapes such as arch tops and half-rounds can be fabricated as secondary units to acous- tically treat unique prime window conditions. Secondary windows are manufactured to match the operation of the prime window unit. Double-hung, slider, and fixed-lite configurations are all available as secondary window units. Specialty acoustical panels are manufactured for use with prime casement, awning, and other projected window types. Secondary acoustical skylight panels are available to provide the acoustical treatment of existing skylights and other sloped glazed window systems (see Figure 9.12). Most acoustical secondary windows are fabricated from aluminum extrusions and offer a variety of finishes and color options to complement the color scheme of the structure. Wood- framed acoustical secondary units are also available when matching the material of a prime wood window is critical. A variety of glass types can be glazed into the secondary window sys- tem. Obscure glass can be installed when additional privacy is required, and a variety of tinted glass options or glass with high-performance coatings can also be glazed into the secondary unit to enhance shading coefficients and thermal performance. STC results of acoustical secondary windows range from STC 29 to STC 33, based on window configuration and glazing type. Install- ing a secondary window to a prime window adds a considerable amount of additional mass and creates a substantial amount of air space between the primary and secondary unit, significantly enhancing the sound deadening performance of the complete window assembly. Historic struc- tures use secondary units for acoustical treatment, enhancement of thermal performance, and to protect historic window components (such as leaded glass and custom wood-frame profiles) from exposure to the elements. Some SIPs providing acoustical treatments in regions where wood windows are predominant offer wood or clad wood prime windows with an acoustical sec- ondary window as their acoustical treatment strategy. Paring standard wood window assemblies with acoustical secondary units provides performance in the STC 40 to STC 44 range. Acoustical secondary doors, or storm doors, are a popular SIP acoustical treatment strategy. Unique existing prime door styles such as arch-top doors or prime doors with distinctive features
182 Guidelines for Airport Sound Insulation Programs Courtesy of SCS/Larson. Figure 9.12. Secondary skylight system. such as leaded glass can be repaired, weather stripped, and acoustically treated with the applica- tion of a secondary door system (see Figure 9.13). As previously referenced, the application of secondary doors over conventional insulated steel or fiberglass replacement door systems is the most predominant use of a secondary door unit. Secondary doors are available in a multi- tude of styles, hardware finishes, and color options, providing SIPs multiple product choices. Secondary acoustical security doors are also available when needed to match an existing sec- ondary security door that requires replacement, or when additional security is required. Many secondary door styles are available with screen options. Although when ventilating through the secondary door the sound attenuating performance of the door is negated, there will be instances in which the owner prefers the ventilation. STC performance of secondary doors ranges from STC 29 to STC 33, depending on door style and glazing. STC 40 to STC 44 perfor- mance is achieved when installed in combination with an insulated steel or fiberglass replace- ment door system. When the decision is made not to replace the existing patio door with an acoustically rated prime patio door unit, the addition of a secondary patio door installed over the existing door or standard replacement door system may be the appropriate treatment option (see Figure 9.14). In markets where wood sliding glass doors are prominent, acoustical secondary sliding glass doors are used to protect the prime door and acoustically treat the door opening. Most applications mount the sliding glass secondary door to the exterior face of the prime patio door frame. In many cases the exterior casing and sill condition of the existing door must be modified to accept
Product Development 183 the secondary door application. The sliding secondary door operates in the same manner as the prime sliding door and creates a multiple-panel, dual-door system. The application of a second- ary patio door may not be an acceptable option in all markets. Programs located in warmer climates may receive strong resistance to the application of a secondary sliding glass door system. STC performance of secondary sliding patio door system ranges from STC 30 to STC 33, depend- ing on door style and glazing. 9.5 Product Manufacturer Requirements 9.5.1 Product Warranty Products installed in SIPs should carry a minimum 10-year product warranty, with the start date being the date of final installation. The warranty must be non-prorated and transferable for the duration of the warranty period. During the 10-year period, the manufacturer is required to, at a minimum: â¢ Repair or furnish a new product, at no charge to the owner, for any manufacturing defects, excluding glass breakage or screen damage; Courtesy of SCS/Larson. Figure 9.13. Secondary window and secondary storm door.
184 Guidelines for Airport Sound Insulation Programs Courtesy of SCS/Larson. Figure 9.14. Secondary sliding patio door. â¢ Warrant the structural integrity of the product, covering sagging or deflection under normal conditions; â¢ Warrant that equivalent replacement parts will be available for the duration of the warranty period; and â¢ Provide a finish warranty, covering blistering, crazing, or peeling of the factory-applied finish. The insulated glass portions of the window and door products must also be warranted to not fail during the 10-year warranty period. A failed insulated glass unit is one that develops a significant obstruction of vision resulting from moisture formation or dust collection between the sealed insulated glass panes, which is caused by failure of the seal. The laminated glass mate- rial should also be warranted to cover edge separation of the glass and laminate, any delamina- tion that obstructs the vision through the glass, and any blemishes that exceed those allowed by industry standards. During the warranty period, the manufacturer or supplier must provide customer service sup- port to address warranty issues, supply replacement parts, and provide technical assistance to owners. 9.5.2 The Buy American Act The Buy American Act was implemented in 1933 to establish a preference for American- manufactured goods used in government-funded projects. This statute provides a definition
Product Development 185 of what are and qualify as American-made goods, along with the proper reporting of their procurement and use. The statute also outlines requirements and guidelines when requesting waivers for using materials not made in America. SIPs that receive AIP funding are required to follow the Buy American Act. Direction for the proper implementation of the Buy American Act can be found in the FAAâs PGL 10-02, Guidance for Buy American on Airport Improvement Program (AIP) or American Recovery and Reinvest- ment Act (ARRA) Projects. The guidance letter states: âIn accepting AIP or ARRA funding, grant recipients are certifying that they will not acquire (or permit any contractor or subcontractor) to use any steel or manufactured products produced outside the United States on any portion of the project for which funds are provided, unless otherwise approved by the FAA.â9 It further states: âThe AIP funded portion of a project includes the grant recipientâs local share.â A copy of the guidance letter can be found in Appendix D. 9.6 Updated Manufacturer and Product Matrixes Updated matrixes of door and window manufacturers and their products may be found in Appendix C. Matrixes offer available information about products offered, performance ratings, STC ranges, and historical applications. 9 PGL 10-02, Guidance for Buy American on Airport Improvement (AIP) or American Recovery and Reinvestment Act (ARRA) Projects, issued by the FAA on February 24, 2010, p. 1. 9.7 Best Practice Recommendations: Acoustical Products 1. Before approving any acoustical window or door product for an SIP, conduct a thorough product review for performance and compliance with program require- ments, including analysis of fabrication information, assembly materials, glazing configuration, and independent test reports from a certified lab. 2. Performance testing should be completed by an independent certified lab in accordance with AAMA/WDMA/CSA 101/I.S.2/A440, Standard Specification for Windows, Doors and Unit Skylights. Based on the geographic location of the SIP, additional testing and product certification may be required, such as in HVHZs. Windows fabricated with a primary and secondary sash assembled as a dual window must be tested and certified in compliance with the DW test criteria. Performance tests must be updated every 4 years since the tests expire 4 years after the initial test completion date. 3. Acoustical performance testing should be completed by a NVLAP-certified lab and in conformance with test procedures from ASTM E90, Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions and Elements. Since acoustical tests do not have an expiration date, SIPs should estab- lish retesting or updated testing criteria. As a baseline, retesting or updated testing should occur at a minimum of every 10 years and whenever a manufacturer makes changes to the product. 4. When reviewing sound performance data, review the TL values to establish at what frequencies the product is providing its best sound attenuating performance.
186 Guidelines for Airport Sound Insulation Programs 5. Review the thermal performance requirements on a routine basis to ensure compli- ance with intermittent code changes. Select a single test method so that all fenestra- tion products of a given material type may be reviewed under the same test criteria. Thermal performance tests must be updated every 4 years since the tests expire 4 years after the initial test completion date. 6. Review the results and recommendations of ACRP Project 02-31 for further infor- mation regarding sustainable and effective noise reduction products and treatment strategies. 7. Take measures to ensure that products are properly installed since the final perfor- mance of acoustical products depends greatly on correct installation, which includes properly preparing the opening to receive the acoustical unit. 8. STC tests provided by an independent certified lab should include the entire door assembly, pre-hung in the frame and completely operational. It is important that the test list the component parts used in the test door assembly to ensure that the doors fabricated for the project match the test door specimen. STC tests conducted only on door slabs should not be accepted because they do not represent the performance of the complete door assembly, including the perimeter seals and threshold. 9. Products installed in SIPs should carry a minimum 10-year product warranty, with the start date being the date of final installation. The warranty must be non-prorated and transferable for the duration of the warranty period.