The basic facts about vinyl windows and doors

November 25, 2012



Basic Facts About Vinyl Windows And Doors - Clera Windows + Doors

There are so many technical terms being used by vinyl window manufacturing and installation companies in their sales and marketing literature that the typical homeowner can’t possibly know what they are being told. The purpose of this article is to simplify and explain some commonly used terms relating to vinyl windows and doors.


This is a generic term which refers to the transparent material in a window, vinyl or otherwise. The most common glazing material used in modern vinyl windows and doors is, of course, glass.

When two or more panes of glass are assembled together to form a single unit to fit into a window or door frame, they are commonly called sealed units. Vinyl windows and doors are typically constructed using a double glazed sealed unit, incorporated into a frame made of vinyl. Double glazing means that two panes of glass have been sealed together.

Low E coatings

A Low E, or low-emissivity, coating is a thin transparent metallic layer that is applied directly to the glass. It is usually applied to the surface between the two panes of glazing and is very commonly used in vinyl windows and doors today.

The advantage of Low E coatings is that they allow solar energy to enter the home through the vinyl window or door and, at the same time, reflect radiant heat back into the room. A vinyl window or door with a good Low-E coating will lower your energy bill because it reflects sunlight back outside in the summer and allows it to come inside in the winter.


A spacer is the material used to maintain a uniform separation between the panes of glass (glazing) in a vinyl window or door. One of the main advances in vinyl window and door technology in the past decade has been the development of low conductivity or “warm-edge” spacers. The best ones are made from metal-reinforced butyl, rubber or insulated silicone. These conduct less heat energy and result in a warmer vinyl window and door product. What you’ll notice is a vinyl window and door that saves you energy and reduced condensation at the edges of the glazing because the glass temperature is higher.

Gas fills

You hear a lot about gas filling in vinyl windows and doors these days. Gas filling is a relatively new window technology that removes the air which is usually found between the two panes of glass in a vinyl window and replaces it with a heavier, inert gas. The gas in the sealed unit gives the vinyl window or door a better insulating performance by reducing conduction heat loss. This happens because the gas fill has a lower conductivity than air. Argon gas is frequently used.

Frame construction

About 1/3rd of a window is the frame and sash. Therefore, it is important to choose a window or door material that is energy efficient. Vinyl window and door frames provide very good thermal barriers and therefore good insulation properties. A high performance vinyl window and door system will provide good temperature transfer barriers and reduce sound transmission.

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