A window is designed to keep out the draught and retain heat on the inside. Unfortunately, few windows achieve this primary function. Most windows allow cold air to get in and allow lots of heat to go out. The effects of low heat retention include huge energy bills. Double glazing the windows reduce heat loss in a room.

Double glazing involves putting two glass panes together. The two glass panes are separated by a vacuum. The vacuum is responsible for the insulating properties of the double glazed windows. The two glass panes are effectively sealed together so that no air from the outside can find its way to the vacuum. Manufacturers include a desiccant when sealing the two panes together. The desiccant ensures moisture does not find its way to the vacuum. Glazed windows can be tinted.

What is the science behind double glazing? Heat loss is minimized in different ways. The two panes increase the distance which the heat has to travel. Heat loss is thus minimized due to the distance. But the vacuum is responsible for most of the heat retention.

To understand how the double glazing works, you need to understand the spread of heat. Molecules of air are in constant motion. Heat is transferred because the molecules knock each other as they move around and transfer heat energy in the process. To reduce heat transfer, the motion of air molecules has to be limited. The vacuum is filled with air to ensure the air molecules do not move around. For this reason, the vacuum acts as an insulator. Some of the air in the vacuum escapes and some air molecules can still get in. But the minimized movement reduces the transfer of heat.  The efficiency of double glazed windows is increased by coating the inside surfaces. Heat from either side is reflected back. The reflective coating keeps harmful UV rays from entering the room.

Noise reduction is an additional benefit of double glazed windows. Noise does not travel through vacuums. Noise from the outside is greatly reduced by double glazed windows. Also, sound from the inside does not get out. This improves the quality of sound from sound systems and enhances privacy. Some manufacturers use nitrogen in the vacuum. The nitrogen enhances the heat retention since nitrogen molecules will not escape easily. Loco Windows and Fascias offer free double glazing demos.

Argon can also be used in the cavity. It is more efficient in insulation than air or nitrogen. Homeowners have the option of using laminated window panes. A plastic membrane separates the two glass panes. Laminated glass is more common in commercial property. Laminated glass provides better insulation. In addition, laminated glass is shatterproof, increasing security.