Window System Description
- Frame Components – each window unit consists of a perimeter frame made of extruded aluminum head, sill and jamb members. For multiple lite windows, the individual lites are divided by extruded aluminum muntins.
- Frame Construction – to assure the rigidity of the window frame, the frame members are joined by flush butting and concealed shear blocks.
- Glazing Provisions – the frame members are designed with glazing pockets, gasket keepers and snap covers for the installation of standard 1″ thick glazing material. The window frame is designed for the glazing to be installed from the interior.
- Thermal Breaks – the frame members are designed with integral elastomeric thermal breaks to minimize thermal conductance.
- Frame Seals – to assure weathertight performance, the window frames are designed with fully sealed joints, head and sill end dams and weep drainage provisions.
FRAME FINISH OPTIONS
- Anodized – clear, dark bronze or black color
- Two Coat Painted – custom color (primer & Kynar color coat)
- Three Coat Painted – custom color (primer, Kynar color coat & clear coat)
- Mill Finish – bare aluminum
WINDOW SIZE LIMITATIONS
- Window Height – because the window unit’s head and sill are integrated into the horizontal wall panel joints, the window height must be in increments matching the wall panel widths. Standard wall panel widths are 24″, 30″ & 36″ and custom widths are available between 24″ & 36″. The maximum window height is 6′.
- Window Width – the window unit’s jamb may be located to coincide with a vertical wall panel joint, or may be located away from the vertical wall panel joints. When located away from a vertical joint, the minimum distance between the window jamb and the vertical joint is 12″. The window unit’s head and sill members may be spliced to provide windows wider than 20′.
- Load/Span Limitations – the maximum allowable window unit size and muntin spacing is determined by the load/span capability of the window support framing and the load/span capability of the muntins. For specific window frame design requirements, reference the Design Data section of this technical bulletin.
- Maximum Lite Size – the maximum lite height and width is determined by the load/span and deflection capability of the glazing material. Refer to the glazing material manufacturer’s specifications and instructions for the specific glazing design requirements.
WINDOW TO WALL ASSEMBLY
- Erection Sequence – the assembled window frame is designed to be installed in sequence with the wall panel installation.
- Support Framing – the window assembly is designed to be supported by interior mounted support framing. The support framing design and material is not provided by Metl-Span. For support framing design requirements, reference the Design Data section of this technical bulletin.
- Window Projection – the window frame is 4″ deep, and is designed to fit flush with the exterior face of the wall panels.
- Head & Sill Fit – the window frame is designed so that head and sill members interlock into the tongue & groove edges of the wall panels above and below the window.
- Jamb Fit (at vertical wall joint) – the window frame is designed for the continuation of the wall panel’s vertical joint gasket between the window’s jamb member and the end folds on the adjacent wall panels.
- Jamb Fit (away from vertical wall joint) – the window frame is designed for the application of a backer rod and joint sealant between the window’s jamb member and the end folds on the adjacent wall panels.
WALL PANEL REQUIREMENTS
- Panel Type & Thickness – the window frame is designed for installation with 2″ & 3″ thick CF horizontal wall panels.
- Side Panels – rather than having to field cut the wall panels for the window opening, the window frames are designed for use with side panels that are factory cut and end folded. The minimum length of wall panels with end folds is 12″.
- Panel Joint Reveal – The window frame is designed for installation with wall panels that have a horizontal joint reveal of 1/2″.
Although panels with joint reveals greater than 1/2″ may be used, such reveals will not match the 1/2″ reveal between the window unit’s head and the above window panel.
- Air Infiltration – multiple lite windows were tested in accordance with ASTM E 283-99. At 6.24 psf air pressure (equivalent to 50 mph wind velocity), the measurable air infiltration rate was 0.05 cfrm/hr2
- Water Infiltration – multiple lite windows were tested in accordance with ASTM E 331-00. At 12.0 psf air pressure (equivalent to 69 mph wind velocity), there was no water leakage.
- Uniform Load Deflection – multiple lite windows were tested in accordance wiht ASTM E 330-02. At 30 psf positive & negative air pressure, the window assembly deflection did not exceed L/175. At 45 psf positive & negative air pressure, permanent set of the window assembly did not exceed 2%.
WINDOW ASSEMBLY OPTIONS
- Factory Assembled – the window frame is factory assembled and shipped to the job site ready for field installation into the wall assembly.
- Factory Engineered – the window frame components are factory fabricated and shipped to the job site for field assembly prior to installation into the wall assembly.
- Components Order – the window frame components are shipped in stock lengths for field fabrication and field assembly prior to installation into the wall assembly.
- Glazing Components – the window units are field glazed. A glazing components package is available as an option with any of the above window frame options. The glazing components include the necessary setting blocks and chairs, foam backers and dams, glazing gaskets and tapes.
- Installation Drawings – submittal drawings and installation drawings will be available for the “Factory Assembled” and “Factory Engineered” window options.
- Assembly Instructions – a window assembly manual will be provided for the “Factory Engineered” and “Components Order” window options.