Glossary
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a
Air Leakage Resistance
A characteristic of a closed window which restricts air passage when the window is subjected to a differential pressure.
Awning Window
A window with a sash that swings outward at the bottom.
Casement/Awning 3300, 3400 & 3500 Series
B
Blow-Out
An assessment of failure or permanent deformation of any part of a window that would cause operational malfunction(s) and/or endanger the user when subjected to test pressures.
Brush type seal
Most commonly found on sliders to facilitate the sliding movement. It consists of a brush that fits into a plastic track mounted on the sash or frame. Helps reduce air leakage.
C
Casement Window
A Window type that has a sash that may be fixed or hinged at the side to open in or out by turning a crank mechanism.
Certification
The process through which an independent body ensures that standards have been met by means of conducting audits and testing.
Combination Window
A combination of two or more complete window assemblies of the same or different types, whose frames are mulled together.
Complete Tear Out
An installation procedure in which the entire window assembly is removed right back to the rough opening and replaced with a completely new window.
Compression Seals
Seals that can be squeezed tightly together between the moving sash and frame.
Condensation
The formation of moisture on the surface of the window.
Conductivity
The ability of a material to conduct heat from the warm side to the cold side.
Conduction
Heat loss in windows that occurs primarily through the edges of the glazing and through the sash and frames.
Convection
Heat loss that occurs due to air movement between the glazings of a window.
CSA-A440
Minimum standards established by the Canadian Standards Association for air tightness, water tightness, wind resistance, condensation resistance, forced entry resistance and ease of operation. It also sets minimum requirements for all components and their materials from hardware, insect screens and weatherstripping to finishes and adhesives.
D
Dew point
The temperature at which the air can hold no more humidity and it condenses to liquid.
Double-Glazed Window
A window containing two layers of glazing with a uniform space in between the layers, usually two panes of glass.
Double Hung
Both sash, top and bottom in a vertical slider, open and close.
E
Emissivity
Relating to windows, the ability of the glazing to allow radiation to pass through it.
Energy Rating, or ER
A scale rating the comparative performance of windows based on three factors: 1) solar heat gains; 2) heat loss through frames, spacer and glass; and 3) air leakage heat losses.
F
Fixed Window
A frame including a fixed light or lights. They do not open.
Frame
The associated head, jamb, sill and, where applicable, mullion and muntin that, when assembled, house the sash or fixed glazing.
G
Gas Fill
An inert gas, usually argon or krypton, pumped into the sealed unit replacing the air.
Glazing
The generic term for the transparent, or sometimes translucent, material in a window or a door. It is most often glass.
H
Head
The horizontal member forming the top of the frame.
Heat Loss
A basic law of nature that heat energy will move from warmer areas to colder areas.
High Emissivity
Relating to windows, glazing that allows radiated energy to pass easily through it.
Hopper window
A frame with a sash that swings inward at the top.
Horizontal Sliding Window
A frame containing two sash and one or both sash operate by sliding sideways in the frame. The sash meet when closed.
I
IGMA
Insulating Glass Manufacturers Alliance
Insulating Glass Unit
Two or more panes of glass spaced apart and hermetically sealed in a factory.
J
Jamb
The upright or vertical members forming the side of the frame.
L
Light
Another term for a pane of glass or glazing in a window.
Low Emissivity
Relating to windows, glazing that restricts the passage of radiation through it.
Low-emissivity, or low-E, coating
A thin metallic layer, only several atoms thick, applied directly to the glazing surface the purpose of which is to reflect longwave energy back towards the source.
M
Mullion
A vertical or horizontal frame member that separates two or more sash, two or more fixed lights, or a combination of sash and fixed lights.
Muntin
A vertical or horizontal sash member that separates two or more lights within a sash.
O
Operable windows
Windows that open.
P
Permanent Deformation
A change in shape or dimension which does not disappear when pressures are no longer applied.
Projecting Window
A frame containing one or more sash, each of which swings horizontally to open in or out (Awning Window).
R
R-Value
A measure of the resistance to heat flow through an object or material.
Radiation
Heat loss that occurs through the window glass.
Relative Humidity
The amount of water vapour in the air as a percentage of the maximum amount the air could hold at the same temperature.
Retrofit
An installation procedure that involves working within the existing frame and replacing the sash and the glazed unit with a new window.
S
Sash
A unit assembly of stiles and rails for holding glass with or without dividing bars and muntins.
SAWDAC
Siding and Window Dealers Association of Canada
Shims
Wedges, usually about 2″ wide used to position the window into the opening and ensure it is level, square and plumb.
Sill
The main cross or horizontal member forming the bottom of the frame.
Single-Glazed Window
A window containing just one layer of glazing, usually a single pane of glass.
Single Hung
A window with only one sash, the bottom sash in a vertical slider, opens and closes.
Solar Gain
The positive contribution to the heating of a building’s interior made by the sun’s energy passing through a window.
Spacer
The strip of material that maintains uniform separation between the layers of glass in the glazing unit of the window.
Sweep Seal
A flexible fin usually made of rubber or polypropylene which is fastened to either the movable sash or the stationary frame and sweeps against the opposing component to form a barrier.
Standards
Minimum requirements, to which compliance is voluntary, for the components, materials and performance of windows.
Stiles (Meeting Stiles)
The stiles of a pair of sash that meet when the sash are installed and in a closed position.
Storm Window
An exterior-mounted window intended for use in conjunction with a separate interior prime window.
T
Thermal Break
An insulating material applied to a high conducting material to slow the transfer of heat.
Triple-Glazed Window
A window containing three layers of glazing with two uniform spaces in between the layers.
Turn and Tilt Window
A frame with a sash that can either tilt inward like a hopper window, or to swing inward like a casement window.
V
Vertical Sliding Window
A frame containing two sash and one or both sash operate by sliding up and down in the frame. The sash meet when closed.
W
Warm Air Spacers
Spacers made from insulating material such as foam, butyl, thermo-plastic, or thermally improved metals and therefore conduct significantly less heat energy than standard spacers.
Water Leakage
The penetration of water that would continuously or repeatedly wet parts of a building or components not designed to be wetted.
Weatherstripping
Material around operating lights designed to reduce air leakage or water penetration or both.
Window Wise™
A national certification program that establishes minimum standards for windows, outlines best practises and trains installers on proper window installation procedures.
