Manufacturer - uPVC Window & uPVC Doors

Glossary

 

Industry Glossary

 

Acrylic: Thermoplastic glazing material.


Air infiltration: The amount of air leaking in and out of a building through cracks in walls, windows and doors.


Airspacer: Component placed at the perimeter of an insulating glass unit to separate the two lites of glass.


Annealed glass: Standard float glass.


Arch-top: One of several terms used for a variety of window units with one or more curved frame members, often used over another window or door opening. Also referred to as circle-heads, circle-tops and round-tops.


Argon: An inert, nontoxic gas used in insulating glass to reduce heat transfer.


Awning: Window with sash swinging outward from bottom.

 

Bay: A combination of window units that projects to the exterior. Usually features a large center unit with two flanking units at 30¡ or 45¡ angles to the wall.

 

Bottom rail: The bottom horizontal member of a window sash or door panel.

 

Bow: A combination window that projects to the exterior. Usually features four or more window units in a radial or bow formation.

 

Capillary tube: Tube placed through airspacer and seal of insulating glass that allows unit to accommodate changes in pressure between time and location of manufacture and time and location of installation, where it is sealed. Usually used to accommodate changes in altitude between plant and job site. Also referred to as breather tube.

 

Casement: Window with sash cranking outward, to the right or left.

 

Cellular PVC: Extruded polyvinyl chloride material used in window and door components and trim. Unlike rigid (or hollow) vinyl, it features a foam or cell-structure inside. It can often be nailed, sawn and fabricated like wood.

 

Check rail: The bottom rail on the upper sash and the upper rail of the lower sash of a double-hung window unit, where the lock is mounted. Also referred to as a meeting rail.

 

Cladding: Material placed on the exterior of wood frame and sash components to provide ease of maintenance. Common cladding materials include vinyl and extruded or roll-formed aluminum.

 

Combination door: A screen or storm door used in combination with a primary door. Storm windows also are referred to as combination windows.

 

Composite: A term used for window or door components that consist of two or more materials, such as glass fibers or wood and plastic. The term also is used for windows and doors that combine two or more materials in the frame or sash construction, such as a product with a wood interior and a vinyl or aluminum exterior.

 

Condensation: Water vapor from the air deposited on any cold surface that has a temperature below the dew point. Sometimes a problem on cold (and poorly insulated) window glass or framing that is exposed to humid indoor air.

 

Corner cleaner: Machine that removes the bead of excess material formed in welding vinyl window corners.

 

Cylinder: A subassembly for a door lock containing a cylinder plug with keyway and a cylinder body with tumbler mechanisms.

 

Design pressure (DP): A measurement of the structural performance of a window or door. Usually specified as one-and-a-half times greater than necessary based on expected building, wind and weather conditions.

 

Divided lites: Separately framed pieces or panes of glass. A double-hung window, for instance, often has several lites divided by muntins in each sash. These designs are often referred to as six-over-six, eight-over-one, etc., to indicate the number of lites in each sash. Designs simulating the appearance of separately framed panes of glass are often referred to as SDLs or simulated divided lites. Designs using actual separate pieces of glass are sometimes referred to as TDLs or true divided lites.

 

Double glazing: Use of two panes of glass in a window to increase energy efficiency and provide other performance benefits. May or may not refer to an insulating glass unit.

 

Drainage cap: Cap used on top of the drainage hole to block dust and insects.

 

Energy Star: A program sponsored by the U.S. Department of Energy that establishes minimum performance standards for windows to be recognized as energy efficient. Four different sets of standards for U-value and solar heat gain have been established for four different climate zones in the U.S. See the Association Directory for more information on the Energy Star Windows program. More stringent requirements are planned for 2009.

 

Extrusion: The process, in which a heated material is forced through a die, used to produce aluminum, vinyl (PVC) and other profiles or components used in the production of windows and doors. Term also is used to refer to the profiles or lineals manufactured by this process and used to make window and door components.

 

Fanlight: A half-circle window over a door or window with radiating bars

 

Fenestration: Originally, an architectural term for the arrangement of windows, doors and other glazed areas in a wall. Has evolved to become a standard industry term for windows, doors, skylights and other glazed building openings. From the Latin word, "fenestra," meaning window.

 

Finger-joint: A toothed joint used to combine two pieces of wood end-to-end.

 

Fixed lite: Non-venting or non-operable window.

 

Fixed panel: Non-operable door usually combined with operable door unit.

 

Flashing: A strip of material that diverts water away from a window, door or skylight.

 

Float glass: Glass produced by a process in which the ribbon is floated across a bath of molten tin. The vast majority of flat glass is now produced using this method. The terms "plate" glass and "sheet" glass refer to older manufacturing methods still in limited use.

 

Flush door: Door produced using two skins or faces separated by a stile-and-rail frame construction at the perimeter. Flush doors may be produced with a hollow core or solid core.

 

Fogging: A deposit or film left on an interior surface of a sealed insulating glass unit due to extreme conditions or failed seals.

 

French door: Generally refers to a pair of hinged doors that open from the middle. Also incorporates wider stile-and-rail components around the glass than typical glazed doors.

 

Friction-weld: A process that uses high-speed vibrations to join materials together.

 

Fusion-weld: A term for a type of corner construction, used with vinyl and other types of windows and doors, in which a small amount of material on the ends of two pieces are melted or softened, then pushed together to form a single piece. This also is referred to simply as a welded corner.

 

Glazing: Glass (and other materials) in a window or door. Also, the act or process of 
fitting a unit with glass.

 

Glazing stop: A component of the sash or door panel that holds the glass in place.

 

Green building: A movement in architectural and building circles aimed at creating structures that are occupant and environmentally friendly. Criteria such as sustainability, energy efficiency and healthfulness are considered.

 

Green strength: The immediate holding power achieved by a sealant or adhesive.

 

Hard-coat glass: A glass product that is coated during the manufacturing process at the molten glass stage. Also known as a pyrolytic coating, this type of coating offers a surface that is generally as durable as an ordinary glass surface, and therefore requires no special handling and does not need to be used in an insulating glass unit. The other type of glass coating is a sputter-coat, which is applied in a secondary process. Sometimes referred to as a soft-coat, these types of coatings generally require some additional care in handling and fabrication and must be used within an insulating glass unit.

 

Heat gain: The transfer of heat from outside to inside by means of conduction, convection and radiation through all surfaces of a house.

 

Heat loss: The transfer of heat from inside to outside by means of conduction, convection, and radiation through all surfaces of a house.

 

Hollow-core door: Flush door constructed with two skins or door faces separated by stiles and rails at the perimeter. Generally, a honeycomb-type support is used inside the door between the two faces.
Hopper: Window with sash that swings inward from the top.

 

Horizontal slider: A window with a movable sash that slides horizontally. Also referred to as a gliding window.

 

Impact-resistant: Term used to describe window and door products that have passed established tests for resistance to windborne debris. Such products are typically used in coastal areas that are prone to hurricanes.

 

Insulating glass (IG): Two or more lites of glass with a hermetically sealed airspace between the lites. The sealed space may contain air or be filled with an inert gas, such as argon.

 

Integrated sash: A sash unit in which the the insulating glass spacer profiles are integrated into the sash profiles. Separate IG construction is eliminated as the two lites of glass are applied and sealed directly to the sash, creating one assembly.

 

Laminated glass: Two or more sheets of glass with an inner layer of transparent plastic to which the glass adheres if broken. Used for enhanced safety and security, as well as sound reduction.

 

LEED rating system: A "green building" rating system established by the U.S. Green Building Council. Currently applicable to new commercial construction and major renovations, the program is being expanded to include residential construction as well. LEED stands for Leadership in Energy and Environmental Design.

 

Lintel: A structural component or beam above a window or door opening that supports the wall above. Also referred to as a header.

 

Lite: A piece of glass. In windows and doors, refers to separately framed panes of glass (as well as designs simulating the look of separately framed pieces of glass). Sometimes spelled "light."

 

Low-emissivity (Low-E) glass: A coated glass product that reflects heat.

 

Masonry opening: Area in a masonry wall left open for windows or a door.

 

MDF: Medium-density fiberboard. A wood-fiber composite used in a variety of window, door and millwork applications.

 

Mechanical window: A term for a product, usually vinyl, in which the corners are assembled using screws or other fastening mechanisms, as opposed to a welded corner construction. Also referred to as a mechanically fastened window.

 

Mortise lock: A lock fitting a rectangular-shaped cavity in the edge of a door.

 

Mullion: A component used to structurally join two window or door units.

 

Multipoint lock: A locking system, operated with one handle, that secures a window or door at two or more locking points.

 

Muntin: Profile or moulding, either vertical or horizontal, used to separate glass in a sash into multiple lites. Generally refers to components used to construct divided lite grids or grilles simulating a divided lite look.

 

Panel: Component, usually wood, mounted within stile-and-rail members of doors. Also used to refer to the entire door.

 

Panning: In replacement window work, the outside aluminum trim that can extend around the perimeter of the window opening; used to cover up the old window material.

 

Picture window: Large, non-operating window. It is usually longer than it is wide to provide a panoramic view.

 

Pivot window: A unit with a sash that swings open or shut by revolving on pivots at either side of the sash or at top and bottom.

 

Pocket window: A unit designed for replacement applications that is installed into the existing window frame after removal of the sash, balance hardware and parting stops. Also called an insert window, these units allow existing interior and exterior trim to be maintained.

 

Polycarbonate: A plastic material used for glazing.

 

Polyvinyl Butyral (PVB): Plastic material used as the interlayer in the construction of some types of laminated glass.

 

Projected window: A window in which the sash opens on hinges or pivots. Refers to casements, awnings and hoppers.

 

Pultrusion: The process used to produce fiberglass composite profiles or components for the production of windows and doors. Term also is used generally to refer to the composite profiles or lineals cut and processed to make window and door components.

 

Radiation: The transfer of heat in the form of electromagnetic waves from one separate surface to another. Low-E glass is designed to reduce this type of heat transfer by reflecting electromagnetic waves.

 

Rail: Horizontal member of the framework of a window sash or door.

 

Reflective glass: Window glass coated to reflect visible light and solar radiation striking the surface of the glass.

 

Resin: A term commonly used within the industry that refers to the raw materials used by PVC extruders to produce vinyl window profiles. The word is also used to describe a liquid material that is used in the production of laminated glass.

 

RF: Radio frequency. Technology used with bar code scanners and other input devices in plant and warehouse tracking systems.

 

Roof window: An operable unit similar to a skylight placed in the sloping surface of a roof.

 

Rough opening: Framed opening in a wall into which a window or door unit is to be installed.

 

Round-top: One of several terms used for a variety of window units with one or more curved frame members, often used over another window or door opening. Also referred to as arch-tops, circle-tops and circle-heads.

 

R-value: Resistance to thermal transfer or heat flow. Higher R-value numbers indicate greater insulating value. R-value is frequently used by the insulation industry and is the reciprocal of U-factor, a value more generally used in the window industry.

 

Safety glass: A strengthened or reinforced glass that is less subject to breakage or splintering and less likely to cause injury if broken. Law requires glass in doors to be some type of safety glazing product, such as tempered or laminated glass.

 

Sash: An assembly of stiles and rails (vertical and horizontal members) made into a frame for holding glass.

 

Sash weights: Concealed cast-iron weights used to counterbalance the sash of older double-hung windows.

 

Self-cleaning glass: Glass treated with a special coating. Currently, commercially available products feature a coating that uses the sun's UV rays to break down organic dirt through what is called a photocatalytic effect. The coating also provides a hydrophilic effect, which reduces the surface tension of water to cause it to sheet down the surface easily and wash away dirt.

 

Shading coefficient (SC): A measure of a window's ability to transmit solar heat, relative to that ability for 1/8-inch clear glass. The lower a unit's shading coefficient, the less solar heat it transmits, and the greater its shading ability. It is being phased out in favor of the solar heat gain coefficient (SHGC).

 

Sheet glass: A transparent, flat glass found in older windows, now largely replaced by float glass.

 

Sidelites: Narrow fixed units mulled or joined to operating door units to give a more open appearance.

 

Sill: The main horizontal member forming the bottom of the frame of a window or door.

 

Simulated divided lites (SDLs): A type of grille or grid design that creates the appearance of a number of smaller panes of glass separated by muntins, but actually uses larger lites of glass with the muntins placed between and/or on the surfaces of the glass layers.

 

Single glazing: Use of a single lite of glass in a window. Generally not as energy efficient as insulating glass or other forms of double glazing.

 

Slab: A term for a complete door panel that has not been prepared for installation into a frame.

 

Slider: A window with a movable sash that slides horizontally. Also referred to as a horizontal sliding window.

 

Smart window: Generic term, sometimes used for windows offering high energy efficiency or windows featuring switchable glass to control solar gain.

 

Solar-control glass: Glass produced with a coating or tint that absorbs or reflects solar energy, thereby reducing solar gain.

 

Solar heat gain coefficient (SHGC): A rating, which is now generally replacing shading coefficient, measuring a window's ability to transmit solar heat. It measures both the solar radiation which is directly transmitted, as well as the solar radiation absorbed by the glass and subsequently transmitted. The lower a unit's solar heat gain coefficient, the less solar heat it transmits, and the greater its shading ability. It is approximately equal to the shading coefficient divided by 1.15. It is expressed as a number without units between 0 and 1.

 

Solid-core door: Flush door produced with a solid material placed within the door skins.

 

Soft-coat glass: A glass product that is coated in a secondary process known as sputter-coating, usually to offer low-emissivity or solar-control benefits. The term refers to the fact that these types of coatings generally require some additional care in handling and fabrication and must be used within an insulating glass unit. A hard-coat or pyrolytic glass is coated during the manufacturing process at the molten glass stage. This type of coating offers a surface that is generally as durable as an ordinary glass surface, and therefore requires no special handling and does not need to be used in an insulating glass unit.

 

Tempered glass: Glass heat-treated to withstand greater than normal forces on its surface. When it breaks, it shatters into small pieces to reduce hazard.

 

Thermal break: A thermally insulating or low-conductance material used between interior and exterior aluminum (or other conductive material) window and door components.

 

Tilt window: A single- or double-hung window whose operable sash can be tilted into a room to allow cleaning of the exterior surface on the inside.

 

Transom: Window used over the top of a door or window, primarily for additional light and aesthetic value.

 

Triple glazing: Use of three panes of glass or plastic with two airspaces between. Generally refers to a sealed insulating unit.

 

True divided lites (TDLs): Traditional window construction incorporating smaller panes of glass actually separated by muntins, rather than simulating such an appearance with larger lites of glass and a muntin grid or grille placed between or on the surfaces of the glass layers.

 

U-factor: Rate of heat flow-value through a building component, from room air to outside air. Also referred to as U-value. The lower the U-factor, the better the insulating value. U-factor, a rating more generally used in the window industry, is the reciprocal of R-value, a rating commonly used in the insulation industry.

 

Ultraviolet light (UV): Invisible rays of solar radiation at the short-wavelength violet end of the spectrum. Ultraviolet rays can cause fading of paint finishes, carpets and fabrics, as well as deterioration of some materials.

 

UPVC: Un-plasticized Polyvinylchloride. An extruded material used for window and door framing.

 

Vinyl: Generic term for polyvinylchloride or PVC, an extruded material used for window and door framing.

 

Weatherstripping/ Gaskets: A material or device used to seal the openings, gaps or cracks of venting window and door units to prevent water and air infiltration.

 

Weep hole / Drainage hole: A small opening in a window or sill member through which water may drain to the building exterior.

 

Weld: A term used for a type of corner construction, used with vinyl and other types of windows and doors, in which a small amount of material at the two pieces are melted or softened, then pushed together to form a single piece. This also is referred to commonly as a fusion-weld.

 

Wind load: Force exerted on a surface by moving air.