Below is a list of window terminology which will help in the home window selection process.
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.
Apron: Inside horizontal trim located under the window stool at the bottom of a unit.
Argon: An odorless, colorless, tasteless, nontoxic gas that is six times denser than air. Replacing the air between two panes of glass with argon gas reduces temperature transfer, making the surface of the glass inside the house closer to the inside temperature.
Awning window: Hinged at the top, this window has a single sash that swings outward from the bottom.
Balance: Device for counterbalancing a sliding sash, usually associated with a double-hung window, so sash may be held open at any given position. Usually a system of cords, weights, springs, spiral devices or block and tackle hardware.
Bay window: A composite of 3 or more windows that project out from the wall. Usually consists of one large center window with two flanking fixed or operating windows at 30- or 45-degree angles to the wall.
Bottom rail: Bottom horizontal member of a window sash.
Bow window: A composite of 3 or more windows in a radial or bow formation. Typically consists of casement windows both fixed and operating. The windows are attached at 10-degree angles to project a more circular, arced appearance.
Brickmold: Standard outside casing around the home window to cover the gap between the window frame and the opening. Nails are driven through the molding to install the window to the framed opening.
Casement window: A window with side hinges that cranks outward for ventilation from either the right or left.
Casement operator: A hardware device used to operate a casement window to any open position.
Condensation: The deposit of water vapor from the air on any cold surface whose temperature is below the dew point, such as a window glass or frame that is exposed to cold outdoor air. Is controlled by limiting the amount of humidity inside of a room relative to the outdoor temperature.
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.
Crank handle: A handle that attaches to an awning or casement operator, used to open the venting window.
Dead-air space: The space between the panes of glass of an I.G. Unit.
Double-hung window: A window with two operable sash which slide vertically.
Double-strength Glass: Glass with a thickness of approximately 1/8".
ENERGY STAR®: ENERGY STAR® is an independent government program establishing a standard set of guidelines to recognize the energy efficiency of various products. ENERGY STAR® guidelines are used in conjunction with a variety of building materials, including windows and patio doors. Over the past ten years, ENERGY STAR® guidelines have helped double the efficiency of windows they endorse.
Frame: The entire window's outside edges, or the head, jambs and sill combined.
Geometric window: Specially designed windows made up of 2 or more angles (i.e., pentagon or trapezoid).
Glazing (pane): The glass panes or lights in the sash of a window. Also the installation of glass in a window.
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.
Head :The horizontal top part of the window frame.
Insulating glass: A combination of 2 or more panes of glass with a hermetically sealed air space between the panes. The space may be filled with an inert glass such as argon.
I.G. Unit (Insulating Glass Unit): Two or more lites of glass separated by a spacer and hermetically sealed at the glass edges.
Jamb: The vertical portions of the window frame.
Keeper: The hook-shaped piece of hardware that it is mounted on the inside sash stile of a casement window in which the sash lock engages.
Krypton Gas: An inert, odorless, colorless, tasteless, non-toxic 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.
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.
Low E (Emissive) 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.
Main Frame: The head, sill and jambs sections of a window.
Meeting rail: The horizontal sections of a pair of sash that meet when the sash are closed
Mullion: A vertical member to structurally join two window units.
Operable window: Window which can be opened for ventilation.
Picture window: Large fixed windows.
Rail: Horizontal member of a window sash or door panel.
R-Value: The measurement of resistance to heat transfer in a material. The higher the R-Value, the better the resistance, the greater the insulation value.
Sash: The part of the window which contains the glass.
Shading coefficient: Decimal value which is the solar gain of a window, divided by the solar gain for a clear single-glass window of the same size. The lower the number - the more efficient the window is at reducing solar heat gains.
Sill: Horizontal member at the bottom of the window frame.
Single-hung window: Window similar to double-hung window, except the top sash is stationary.
Slider Window: Home windows in which the sash move horizontally.
Stile: Vertical member of a window sash or door panel.
Tempered glass: Special heat-treated, high-strength safety glass. When broken, the glass breaks into pebbles instead of shards.
Transom: This is a fixed or operable window placed above a larger window. They can be used for added ventilation or lighting, but are often times used only for decoration.
Triple glazing: Three panes of glass with two air spaces between, commonly consisting of an insulating glass with a separate storm sash. Also available in an insulating window in a single frame.
U-Value: A U-value indicates the rate of heat transfer. The lower the U-value number, the slower it transfers heat from a warm area to a cold area.
Weather-stripping: Material used to form a weather-resistant seal around operable sash.
|Services||Products||Photo Gallery||WDR links|
|Replacement Windows Online Price Quote
Porch Enclosure Price Quote
In-Home Consultation & Quote
awning replacement windows, bay window,
bow window, fixed replacement windows,
picture windows, single/double slider windows,
single/double hung windows, custom vinyl windows
Vinyl Siding & Eavestrough
Single/Double Hung windows
Single/Double Slider windows
WDR Service Area & Installations Map