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A

AAMA
American Architectural Manufacturers Association. A national trade association that establishes voluntary standards for the window, door, storefront, curtain wall, and skylight industries.

Absorptance
The ratio of radiant energy absorbed to total incident radiant energy in a glazing system. 

Accessory Groove
A shape included on a fenestration product frame that is designed to mate with installation accessories.

Acid Etching
A process used in decorative glass where hydrofluoric acid is applied to the surface of the glass. Where the acid contacts the glass surface, the glass becomes frosted with a matte finish (similar to the effect caused by a sandblasting process). Patterns can be applied using special wax coatings on the glass. Where the glass is coated with wax, no corrosion of the surface will take place.

Acrylic
A thermoplastic with good weather resistance, shatter resistance, and optical clarity, used for glazing.

Adhesion
That property of a sealant/compound that measures its ability to bond to a surface on which it is applied

Adhesion Failure
The pulling away of a sealant/compound from the surface it is applied to, resulting in water penetration.

Aerogel
A microporous, transparent silicate foam used as a glazing cavity fill material, offering possible U-values below 0.10 BTU/(h-sq ft-°F) or 0.56 W/(sq m-°C).

Air Chambers
Small honeycomb spaces within the sash and frame which help to insulate and strengthen the window.

Air Infiltration
The amount of air that passes between a window sash and frame. In windows it is measured in terms of cubic feet or air per minute, per square foot of area. The lower the number, the less air the window lets pass through. 

Air Latch
Latch mechanism on the interior face of the sash that retains the window in a partially open position for ventilation. 

Angled Exterior
A sloped extension from the frame that adds an aesthetically-pleasing dimension to the exterior of the window.

Argon Glass
A colorless, odorless, nonflammable, non-toxic, and above all a safe, inert gas that is heavier than air. When the air between two windowpanes is replaced with Argon Gas, the energy efficiency of the window increases even more. It also acts as a sound barrier, helping to make a home quieter as well as more energy efficient.

ASTM
American Society for Testing and Materials. Organization that develops methods for testing of materials.

Awning Window
A top-hinged window that swings outward for ventilation.

B

Backerboard
A flat material used on the face of the house, between the studs and the siding, to provide a nailable surface for the siding.

Balance Covers
A snap in covering that conceals the EvenForce™ block and tackle balance system within the window frame, helping to keep dirt and dust out of the chamber.

Balance System
Device for holding vertically sliding sash in any desired position through the use of a spring or weight to counterbalance the weight of the sash.

Bay Window
An angled combination of three windows that project out from the wall of the home. The windows are commonly joined at 30- or 45-degree angles.

Beveled Exterior
An angled extension from the frame that adds an aesthetically-pleasing dimension to the exterior of the window.

Beveled MasterFrame
Some Alside windows feature a unique fusion-welded design that accommodates differing installation methods and architectural styles. It is the angled portion of the masterframe profile that adds a three dimensional appearance to the exterior of the window.

Block and Tackle Balance System
The block and tackle system utilizes a high-density nylon cord pulley action which is attached to a moveable block that travels up and down within a metal chamber. Tension from a heavy duty coil spring at the top of the block creates the proper resistance necessary for smooth operation of the window sash.

Bow Window
An angled combination of windows in 3-, 4- or 5-lite configurations. The windows are attached at 10-degree angles to project a more circular, arced appearance.

Buttlock
The bottom edge of a siding or soffit panel, or accessory piece, opposite the nailing slots, which locks onto the preceding panel.

Butyl
A rubber material that seals the glass to the spacer, creating an airtight and watertight IG unit. Butyl has the lowest gas permeability of all rubbers.

C

“C” Class Mull
A reinforced structural mull package (designed to achieve a design pressure (DP) rating of 50) utilizing steel reinforcement and a steel “L” bracket at the top and bottom of the mull which transfers the wind load to the opening.

“C” Class Window
An option on select window models used to achieve a higher design pressure (DP) rating. This option incorporates High Performance Tilt Latches on the bottom sash, reinforces sash stiles, and a third lock on windows 36 inches wide and above.

Cam Lock and Keeper
The mechanisms which pull the sash together when placed in the locked position.

Capillary Tubes
Small hollow tubes which penetrate the spacer system of an insulating glass unit. They allow pressure equalization between manufacturing locations, shipping, and installation locations. Since the insulating glass unit is not permanently sealed, the air space cannot be filled with Argon gas.

Casement Window
A window with a side-hinged sash that opens and closes outward by a crank handle mechanism. Available in continuous mainframe, with multi-lite configurations.

Channel
The area of the accessory trim or corner post where siding or soffit panels are inserted. Channels also refer to the trim itself, and are named for the letters of the alphabet they resemble (e.g., J-channel, F-channel, etc.).

Center of Glass U- and R-values
The U- and R-values measured from the center of the glass to 2-1/2" from the frame.

ClarityOne Glass
A chemical treatment that when applied to glass, helps to create a smoother surface that won’t attract or hold dirt and dust. Established by PPG Industries.

ClimaTech™
The brand name for the insulated glass unit that is present in Alside’s insulating glass packages. A ClimaTech unit will contain either two or three panes of glass, with one or two of those panes being a Low E surface. It will utilize the SST warm edge spacer system and contain either argon or krypton gas.

ClimaTech™ 2
Double glazed unit with PPG intercept® spacer, two surfaces of PPG Solarban 60® LowE glass and argon gas.

ClimaTech™ Plus
Double glazed unit with foam spacer, one surface of PPG Solarban 60® LowE glass and argon gas.

ClimaTech™ TG2
Triple glazed unit with PPG Intercept® spacer, two surfaces of PPG Solarban 60® LowE glass and two spaces filled with argon gas. (Ultramaxx only!)

Condensation
The deposit of water vapor from the air on any cold surface whose temperature is below the dew point, such as a cold window glass or frame that is exposed to humid indoor air.

Condensation Resistance Factor
A measure of the effectiveness of a window or glazing system to reduce the potential for condensation. The higher the condensation resistance factor, the more efficient the window and glazing system.

Conduction
Energy transfer from one material to another by direct contact.

Convection
Heat transfer by currents that flow from a warm surface to a colder one.

Course
A row of panels, one panel wide, running the length of the house from one side to the other, or, in the case of vertical siding, from top to bottom.

Coved Exterior
An arced extension from the frame that adds an aesthetically-pleasing dimension to the exterior of the window.

Coved Glazing Beads
A contoured piece of vinyl that holds the glass in place within the sash and adds an elegant, finished look.

D

Dead-air space
The space between the panes of glass of an I.G. Unit.

Deadlite
A piece of glass or IGU with a sash profile around it; not set within the main frame of a window unit.

Desiccant
A material used in insulating glass to absorb water vapor which causes fogging.

Double Hung Window
A window that has two operable sash which slide vertically.

Double-strength Glass
Glass with a thickness of approximately 1/8".

Dry glazing
An alternative method of placing glass in a door or window. No glazing mastic is used. Dry glazing is recommended whenever reflective coatings are glazed to first surface.

Dual-durometer
An elastomeric material with two different degrees of hardness.

E

Egress Code
The code that requires a minimum opening of a window for persons to exit or firefighters to enter a building.

Energy Star
A voluntary partnership between the U.S. Department of Energy , the U.S. Environmental Protection Agency, and the fenestration industry. It is designed to assist consumers in the recognition of energy efficient products - and promote the environmental and economic benefits of these products. Windows qualify for the ENERGY STAR label when they meet or exceed the established guidelines for energy efficiency. This recognition is granted to only the most advanced energy efficient products on the market.

Extruded screen frame
Different from a Roll formed frame, this frame is pressed through a form or die.

EvenForce™
Alside’s brand name for its block and tackle balance system. A balance system is a device for holding the vertically sliding sashes in any desired position within the window mainframe.

F

Fenestration
The placement of window openings in a building wall, one of the important elements in controlling the exterior appearance of a building. Also, a window, door or skylight and its associated interior or exterior elements, such as shades or blinds.

Fixed Lite
A pane of glass installed directly into non-operating framing members; also, the opening or space for a pane of glass in a non-operating frame.

Fixed Panel
An inoperable panel of a sliding glass door or slider window.

Fixed Window
A window with no operating sashes.

Flashing
A thin, flat material, usually aluminum, positioned under or behind J-channels, corner posts, windows, etc., to keep draining water from penetrating the home.

Fusion-welded
The process of joining materials by melting them together with extreme heat (over 500ºF), resulting in the materials uniting into a one-piece unit.

G

Garden Window
Designed much like a bay or bow window, a garden also extends from the wall to the exterior of the home. It is built in a square or rectangular shape at right angles. The two side lights often operate for added ventilation.

Gas Fill
A gas other than air, usually argon or krypton, placed between window or skylight glazing panes to reduce the U-factor by suppressing conduction and convection.

Geometric
Specially designed windows classified as either Straight line Geometrics such as rectangles, triangles, trapezoid, octagons, pentagons, etc., or Radius Geometrics which include half-rounds, quarter-rounds, full-rounds, sectors, ellipses, eyebrows, etc.

Glass
An inorganic transparent material composed of sand (silica), soda (sodium bicarbonate), and lime (calcium carbonate) with small quantities of alumina, boric or magnesia oxides. Available Styles: Clear, Bronze, Grey and Tinted. · Glazing - The process of sealing the glass to the sash.

Glazing
Bead A strip of vinyl which surrounds the edge of the glass and holds it in place in conjunction with other sealants.

Glazing Bead
A molding or stop around the inside of a window frame to hold the glass in place.

Grids
Decorative horizontal or vertical bars installed between the glass panes to create the appearance of the sash being dividing into smaller lites of glass.

H

Head
The horizontal top portion of the main frame.

Head expander
A vinyl shape cut the width of a product and placed on the head, fitting over it snugly. This piece is used as a filler to expand or lengthen the unit from the head and take up the gap in the opening between the unit and the opening in the unit.

Hook accessory
Accessories that snap to the hook frame and provide easy installation.

Hopper Window
A window with a bottom-hinged sash that opens inward for ventilation.

I

I.G. Unit (Insulating Glass Unit)
Two or more lites of glass separated by a spacer and hermetically sealed at the glass edges.

Insulating Air Chambers
Various chambers within the sash and masterframe, which help to insulate and strengthen the window.

IntegraWeld
The fusion-welding process of some Alside windows.

J

J-channel
Integral extension on the outside of a new construction window that eases installation on siding applications.

Jamb
A vertical member at the side of a window frame or the horizontal member at the top of the window frame, as in head jamb.

K

Keeper Rail
The horizontal section of the sash where the keeper is attached.

Keeper Stile
The vertical section of the sash where the keeper is attached.

Krypton Gas
An inert, odorless, colorless, tasteless, nontoxic gas which is about 12 times denser than air. It is used to replace air between the glass panes to reduce temperature transfer and deter convection. Used when a higher performance is desired than that produced with Argon gas.

L

Laminated Glass
Two or more pieces of glass bonded together over a plastic interlayer.

Lift Handle
A handhold for raising and lowering the sash. Handle implies that the handhold is not continuous across the sash.

Lift Rail
A handhold for raising and lowering the sash. Rail implies that the handhold is continuous across the sash.

Lite
A unit of glass in a window.

Lock Rail
The horizontal section of the sash where the cam lock is attached.

Lock Stile
The vertical section of the sash where the cam lock is attached.

Low E (Emissivity) Glass
Glass with a transparent metallic oxide coating applied onto or into a glass surface. The coating allows short-wave energy to pass through but reflects long-wave infrared energy which improves the U-value. Microscopically thin, virtually invisible, metal or metallic oxide layers deposited on a window or skylight glazing surface primarily to reduce the U-factor by suppressing radiative heat flow. A typical type of low-E coating is transparent to the solar spectrum (visible light and short-wave infrared radiation) and reflective of longwave infrared radiation.

M

Main Frame or Masterframe
The head, sill and jambs sections of a window.

Mechanically Fastened Frame
Refers to frames fastened with screws.

Meeting Rail
The part of a sliding glass door, a sliding window or a hung window where two panels meet and create a weather barrier.

Meeting Stile
The vertical section of a pair of sash that meet when the sash are closed.

Mesh
Fabric made of either fiberglass or aluminum, used in the making of screens.

Mullion
A vertical or horizontal connecting unit between two or more windows.

Mylar
A weatherstripping material that is present where the sash frame meets the masterframe. Adds increased resistance to air infiltration.

N

Nailing Fin
An extrusion attached to the main frame of a window used to secure the unit to the rough opening.

NFRC
National Fenestration Rating Council.

O

Obscure Glass
Glass that has been made translucent instead of transparent.

Oriel
A window with the meeting rail located off center of the frame. Most oriels have a 60/40 configuration.

Origin II™
The virgin uPVC vinyl used in all Alside windows. The material’s low thermal conductivity makes it the best choice for window manufacturing. Will not rot, peel, blister, swell or deteriorate from corrosion or pitting.

Overlapping and Interlocking Meeting Rail
A patented meeting rail which overlaps and interlocks both sash.

P

Patio door
A glass door that slides opens and close on adjustable tandem rollers. Available in 2- or 3-lite configurations with the operable panel available in any position.

Picture Window
A window that has no moveable sash.

Pivot Alignment System
An exclusive hinge-type system used on hung windows. This system attaches the sash to the balance, creating perfect alignment between the sash and frame, while allowing the sash to tilt inward for cleaning. 

Plumb
A position or measurement that is truly and exactly vertical, 90° from a level surface.

Positive Lock
Area below the nailing hem that the buttlock locks into.

Pull Handle
A handhold for sliding the sash back and forth. Handle implies that the handhold is not continuous across the sash.

Pull rail
A handhold for sliding the sash back and forth. Rail implies that the handhold is continuous across the sash.
 

Pull Stile
A handhold for sliding the sash back and forth. Stile implies that the handhold is continuous across the sash

Q

R

R-value
A measure of the resistance of a glazing material or fenestration assembly to heat flow. It is the inverse of the U-factor (R = 1/U) and is expressed in units of hr-sq ft-ºF/Btu. A high-R-value window has a greater resistance to heat flow and a higher insulating value than one with a low R-value.

Radiation
Wave energy transmitted directly from one object to another through the atmosphere or through transparent or translucent materials. The energy radiated is transmitted, absorbed, reflected or a combination of all three. Energy from the sun reaches the earth by radiation and a person’s body can lose heat to a cold window or skylight surface in a similar way.

Rail
The horizontal sections of the sash.

Raised Exterior
An angled extension from the frame that adds an aesthetically pleasing dimension to the exterior of the window.

Relative Humidity Condensation Point
The relative humidity level at which visible water vapor or other liquid vapor begins to form on the surface of the sash or frame, based on an inside temperature of 70E F and an outside temperature of 0E F. The higher the percentage, the more moisture the air can hold before condensation will occur.

Roll formed Screen Frame
A method of fabrication in which a flat (usually metal) material is placed on a machine where the material is formed into shape using differently shaped rollers and pressure.

S

Sash
The part of the window which contains the glass.

Sash Alignment System
An exclusive hinge-type system used on hung windows. This system attaches the sash to the balance, creating perfect alignment between the sash and frame, while allowing the sash to tilt inward for cleaning.

Sash Limit Locks
A feature that allows a window to be safely raised to a certain height.

SecureEST
Laminated glass using a 30 mil. plastic interlayer bonded between two layers of glass by heat and pressure. Primarily for security. Does not meet coastal requirements for impact resistance.

Shading Coefficient
The ratio of solar heat that is transferred through a glazing material relative to the solar heat transferred through 1/8" clear glass. The lower the number the more efficient the window is at reducing solar heat gains.

Sill
The horizontal, bottom section of the main frame.

Sill Angle
Extrusion accessory fits on bottom of window to adjust for any out-of-squareness.

Sill Extender
An extrusion that is attached to the bottom of the window to cover the gap between the sill and the rough opening.

Single Hung
A window in which one sash slides vertically and the other sash is fixed.

Single-strength Glass
Glass with a thickness of approximately 3/32".

Slider Window
A window in which the sash move horizontally. Sliders are available in a 2- or 3-lite configuration, with the 3-lite having operable end vents.

Sloped sill
The sill of the window that has a downward slope to the outside. This sill has sufficient degree of slope to aid in water runoff.

Soffit
Material used to enclose the horizontal underside of an eave, cornice, or overhang. Some soffit panels may also be used as vertical siding.

Solar Heat Gain (SHGC)
The fraction of solar radiation admitted through a window or skylight, both directly transmitted and absorbed and subsequently released inward. The solar heat gain coefficient has replaced the shading coefficient as the standard indicator of a window’s shading ability. It is expressed as a number between 0 and 1. The lower a window’s solar heat gain coefficient, the less solar heat it transmits and the greater its shading ability. SHGC can be expressed in terms of the glass alone or can refer to the entire window assembly.

Spacer
Material placed between two or more pieces of glass in order to maintain a uniform width between the glass, and prevent sealant distortion.

SST non-metal Spacer
A solid silicone foam spacer covered with Mylar. It is sealed to the edge of the glass and then sealed with butyl for greater energy efficiency.

Stepped Sill
An exclusive triple-stepped, sloped sill design.

Stile
The vertical sections of the sash.

Stucco Fin
An extrusion used in stucco home installations that is attached to the main frame to create a smooth, finished look for both the window and the stucco.

SunClean™ Self-Cleaning Glass
PPG SunClean™ self-cleaning glass is a coated glass product with photocatalytic and hydrophilic properties that combine to result in windows that are easier to clean. SunClean™ is available on ClimaTech™, ClimaTech™ Plus, and ClimaTech™ TG2 glass units. It is not available on ClimaTech™ 2.

T

Tape Glazing
Two-sided tape used to secure and seal the glass to the sash.

Tempered Glass
Glass with a surface compression of not less than 10,000 psi, or an edge compression of not less than 9,700 psi. When broken, the glass breaks into pebbles instead of shards.

Tilt Latch
Mechanism that unlocks the sash and allows it to tilt in from the main frame.

Tilt-in/lift-out sash
A sash that can be tilted to the interior and removed for cleaning and is manufactured by welding.

Total Unit U- and R-values
The U- and R-values of the window calculated from the average of the center of glass, edge of glass and frame U- and R-values. It is the reciprocal of the R-value.

Tri-durometer
An elastomeric material with three different degrees of hardness.

Trucapture™ Sloped Sill
The sill of some Alside double-hung windows that has a downward slope toward the outside with a capture dam that helps to keep water from infiltrating the base of the bottom sash. Sloped sill assists water drainage to the exterior of the window.

U

U-value
A measure of the rate of non-solar heat loss or gain through a material or assembly. It is expressed in units of Btu/hr-sq ft-ºF (W/sq m-ºC). Values are normally given for NFRC/ASHRAE winter conditions of 0ºF (18º C) outdoor temperature, 70º F (21º C) indoor temperature, 15 mph wind and no solar load. The U-factor may be expressed for the glass alone or the entire window, which includes the effect of the frame and the spacer materials. The lower the U-factor, the greater a window’s resistance to heat flow and the better its insulating value.

UV Block or UV Reflection
The percent of ultraviolet rays blocked from being transmitted through the glass. The higher the number the lower the percentage of ultraviolet rays transmitted through the window.

United Inches
The summation of one width (rounded up to the nearest whole number) and one height (rounded up to the nearest whole number).

Ultraviolet Light (UV-Light)
The invisible rays of the spectrum that are outside of the visible spectrum at its short-wavelength violet end. Ultraviolet rays are found in everyday sunlight and can cause fading of paint finishes, carpets and fabrics.

V

Vent-lok
Latch mechanism on the interior face of the sash which retains the window in a partially open position for ventilation.

Visible Light
The portion of the electromagnetic spectrum that produces light that can be seen. Wavelengths range from 380 to 720 nanometers.

Visible Light Transmittance
The percentage of light that is transmitted through glass in the visible light spectrum (380 to 720 nanometers). The higher the number the higher the percentage of visible light transmitted through the window.

W

Weather-stripping
Material used to form a weather-resistant seal around operable sash.

Weep flaps
A weep hole that is covered with vinyl flap that allows water to escape, while keeping insects out.

Weep Holes
Small openings designed to allow water to escape that might otherwise accumulate in a window's sill.

Weep Slots
Slots or holes in the sill (bottom) member of the sash frame that provides an outdoor release of infiltrated rainwater.

Wet Glazing
A silicone-based substance used to secure and seal the glass to the sash.

Wood blocks
Pieces of plywood that come in different thickness, depending on the depth of the hook of the frame. They are used to make the window flush with the opening it is filling. They are also used to assist in pre-mulling windows together and give the screw more to bite into when joining the windows.

X

Y

Z

Zinc Oxide
A chemical added to certain types of laboratory and studio glass. The chemical makes the glass more elastic, which aids in the forming of glass using glass-blowing techniques.