TATVA INSTITUTE OF TECHNOLOGICAL STUDIES,MODASA

Window Terminology Windows are factory assembled as complete units, often with the exterior casing in place. The basic parts are the glazing, the sash, and the frame. Glazing refers to the clear glass or plastic portions of a window. (the glass within each section may also be called a pane or light) The sash is the part that holds the glazing and the frame is the fixed part of the assembly that receives the sash.

Anatomy of a Window 1. Tracks 2. Screen 3. Mounting Flange 4. Exterior casing 5. Head jamb 6. Weatherstripping 7. Sash 8. Glazing 9. Muntins 10. Removable storm panel 11. Sill

Types of Windows Casement Have a single hinged side that swings inward or outward Outward-swinging sash does not get in the way of furniture and the wind tends to keep push outward-swinging sash against the weatherstripping making a tighter seal. Hardware consists of a rotary opener, a hinge assembly, and a sash lock.

Types of Windows Awning / Hopper Awning windows swing outward at t he bottom. A hopper window is similar except that the sash swings inward at the top. Both types provide protection from rain while open. Hardware includes hinges, pivots, and sash support arms.

Types of Windows Horizontal Sliding Resemble casement windows in appearance. However, the sashes slide horizontally in tracks or guides, located on the sill and head jamb.

Types of Windows Double Hung Consists of an upper and lower sash that slides up and down in channels in the side jambs. Each sash has springs or balances to hold it in any position. Some types allow the sash to be removed or pivoted for easy cleaning, painting or repair. Hardware includes one or two metal sash locks.

Frame & Sash Materials Any of the basic types of windows can have sashes and frames made of wood, metal, vinyl, fiberglass, or wood composites. Hybrid windows are a combination or two or more materials

Wood Clad-Wood Window Wood window frames and sashes should be made from a clear grade of all-heartwood stock. Species commonly used are ponderosa pine, cedar, cypress, and spruce. Some wooden windows are referred to a “wood-clad” meaning the exterior is covered or “clad” in another type of material such as vinyl or aluminum. Wood-clad windows never need to be painted.

Metal Made from steel or aluminum these windows are lighter and less costly than windows made from other materials. Require less maintenance than wooden windows. Available with baked on or anodized finishes. Are very common in some parts of the country and less common in other parts, especially areas where winters are cold as metal windows experience greater heat loss. Also moist interior air has a tendency to condense on metal windows. The most efficient metal windows have two piece frames separated by a thermal break. Normally installed via a nailing flange.

Vinyl, Fiberglass, & Composites Structural PVC Window Windows with structural PVC (polyvinyl chloride) sashes and frames are easy to maintain. The vinyl is colored all the way through and resists attack from insects. The hollow channels in these windows are insulated making them very energy efficieint.

Vinyl, Fiberglass, & Composites Window frames can also be made of fiberglass, which is a polyester-based material reinforced with very thin glass strands. Like vinyl, they come in hollow and insulated types. Fiberglass is stiffer and stronger than vinyl. Composite windows are made from a mixture of polymers (plastics) and wood under pressure. They have properties of solid wood but are more decay resistant.

Energy Efficiency Energy efficiency of a window depends on more than one component. For example a window with energy efficient glazing would still experience energy losses if it had faulty weatherstripping. Accurate ratings of windows compare glazing, weatherstripping, materials, and construction.

Standards & Certification The Canadian General Standards Board or CGSB sets the minimum durability on edge seals on insulated glass units. CSA in conjunction with the Canadian Window & Door Manufacturers Association came up with a window performance rating known as CSA-A440. This rating considers a windows air tightness, water tightness, wind load resistance, condensation resistance, forced entry resistance, ease of operation, hardware, insect screens, weatherstripping and finishes. The National Building Code of Canada states that all windows meet the CSA –A440 standard. This standard in updated yearly.

Standards & Certification All windows sold in Canada also have an ER Rating. This is a comparative performance rating based on three factors; Solar heat gains Heat loss through frames, spacers, and glass Air leakage

Standards & Certification Finally windows sold in Canada will have a IGMAC Logo on them. This stands for the Insulating Glass Manufacturers of Canada and it applies to the sealed unit only. It can be found etched into the glass or the spacer between the panes of glass. IGMAC certified products will carry the logo and the manufacturers name.

Glazing In all provinces in Canada we now use insulating glass windows in home construction (sometimes called double-glazed windows). They are made with two or more sheets of glass separated by an air space. The edges are sealed to trap air between the sheets, which provides the insulation. Different types of glazing are available.

Types of Glazing Low-e glazing; also called Low-Emissivity, means that the glass radiates less heat to the outdoors than regular glass. In some types a special coating is applied to one glass surface facing the air space. This can reduce energy flow by as much as 50%. Heat-absorbing glazing; contains special tints that enable it to absorb large amounts of solar energy. Gas-filled glazing; air between the glazing is replaced by a heavier gas such as argon or krypton. The heavier gas increases energy efficiency.

Weatherstripping The main purpose of weatherstripping around a window is to prevent air from leaking between the sash and the frame. It can be made from various flexible materials such as foam and fibrous pile. Over time it will loose its effectiveness and must be replaced… it must never be painted or stained.

* Source: (1) Carpentry & Building Construction / Feirer & Feirer (2) Sill to Sash: A Professionals Guide to Windows & Doors