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The Science Behind Double Glazed Windows

Science Behind Double Glazed Windows

You probably know the benefits of double glazed windows, but do you understand the Science Behind Double Glazed Windows? In this post, we are going tell you about the 5 components of double glazed windows and how they work together to efficiently:

  • Insulate your home and decrease energy bills
  • Give you a better view
  • Increase security
  • Filter out noise

The window frame

Over the years, window frames have been made of wood, aluminium and fiberglass, but today some of the best double glazed windows come with uPVC frames.

uPVC makes outstanding window frames because it is exceptionally strong  and weather resistant. Whether it is made into awning, chamfered or sculptured window frames, uPVC increases the security of homes and businesses by its strength and functions efficiently for years thanks to its resistance to sun and rain.


The glass

Double glazed windows earn their name from having two panes of glass. A window with one pane of glass slows the transfer of heat between an indoor and outdoor environment, while also filtering out some sound waves. Installing two panes of glass in a window doubles the insulation that the window provides and the amount of noise that it filters out.

When necessary, double glazed windows can be made with specialty glass, for instance solar control, low-e and self-cleaning glass.

Spacer bar and desiccant

A spacer bar, sometimes also called a profile, is a continuous hollow frame that separates the two panes of glass in a double glazed window.  Most spacer bars are made out of aluminum, because it is reasonably priced and flexible which makes it easy to work with.

A double glazed window’s spacer bar is filled with a desiccant. The desiccant which can be a variety of products, including silica pellets and zeolite spheroids, absorbs any humidity from the weather or washing that manages to creep in between the panes of glass. This keeps condensation from building up and obstructing the view through the window.

Insulating gas

The space between the glass of a double glazed window depends on the size of the window and the type of glass that is used, but it is generally between 4 and 20 mm wide. This cavity is filled with insulating gas to give the window one more vital layer of insulation.

Before the window cavity is filled with insulating gas, all the ambient air is removed to eliminate humidity and then Argon or dehydrated air is pumped in. The insulating gas in a double glazed window significantly increases the window’s energy efficiency and its ability to block sound waves.


Double glazed windows have two important seals. The primary seal is placed over the spacer bar and between the two panes of glass. This seal is responsible for keeping the insulating gas in and humidity out of the window cavity.

The second seal goes completely around the window unit. This seal helps hold all the components together and prevents drafts from seeping in around the window once it is installed.

The benefits of double glazed windows are not just vender hype. They are true benefits that come from the components of carefully designed double glazed windows.

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