How does double glazing work?

Double glazing insulates against heat transfer between two different temperature zones by creating an air difference (inside and outside). In an IGU unit, two panes of glass are sealed together and divided by a spacer strip. The distance between the panes (usually 6-12mm) provides an air gap that delays thermal transfer (hot or cold) through conduction – it doesn't 'trap heat,' but it does delay heat movement to minimise heat loss. Since air cannot flow through the small gap between the panes, convection is delayed, reducing heat transfer.

How does double glazing reduce heat loss?

Through the use of the thermal cushion and insulation of the air stored in the enclosed unit, double glazing eliminates heat loss. When cold air strikes the exterior pane of glass, the temperature is transferred to the Argon gas layer. Argon gas has a 34% lower thermal transfer rate than air, which delays heat transfer between two different temperatures.

As a result, the Argon layer transfers less of the temperature difference to the internal glass pane, which stays at a temperature that is halfway between the Argon glass and the room. Similarly, Argon gas slows the movement of heat from the inside out as warm air from the room reaches an internal pane of glass. And heat is retained in the room. In a double glazed unit, the outside pane of glass and the internal will be different temperatures.

How does double glazing reduce noise?

Sound is an energy that travels in waves, similar to sea waves, by vibrating the molecules in the air and the objects it comes into contact with. As sound waves strike glass, it vibrates at the frequency of the sound wave and transmits the vibration to the air molecules on the other hand.

Dense structures absorb the energy as the sound wave travels, lowering the frequency of the waves as they pass through. This is why you can hear people talking on the other side of a wall if you place your ear to it, but not if you move away from it. Since sound has a longer wave vibration than light, it may bend (diffract) around corners, making it far more difficult to contain. Even if your window is closed, you will hear a lot of noise if you have a trickle fan. It also ensures that if the double-glazed unit's seals break, you'll notice a rise in noise leaking through the window.

By removing some of the energy and slowing the vibration frequency as it passes through the glass and the Argon gas coating, double glazing eliminates noise. The sound wave is slightly reduced and the echo is slightly louder as it travels through the other side of the glass. However, disrupting sound waves and frequencies as they move through a substance is the secret to eliminating noise as much as possible. This can be accomplished by layering various glass thicknesses close together.

Everest Acoustic glass uses 6mm and 6.8mm panes in double and triple glazing. When the waves pass through, an extra special laminate coating absorbs more energy and reduces the frequency. Acoustic glass can minimise noise by up to 40 decibels due to its unique properties (in triple glazing).

How does double glazing reduce condensation?

The air we breathe is full of small molecular water droplets that are invisible to the naked eye. The molecules in warm air are far apart, which traps the moisture, but as the air cools, the molecules move closer together, allowing the moisture to escape. The 'dew point' is when molecules are so close together that they blend into visible liquid.

When moist air comes into contact with a cold surface, such as a windowpane, condensation occurs. When you boil a kettle, cook food, or take a hot shower, the air becomes saturated with moisture, which is why kitchen windows and bathroom mirrors are so steamy. We also expel moisture through our breath, which is why we wake up with condensation on our bedroom windows. The stored air within the double-glazed sealed device often contains a small amount of moisture that could form on the glass if the temperature difference changes. 

Since double glazing is not as cold as single glazing, it helps to minimise condensation on the inside of your windows (inside the room). The air gap between the two panes of glass within the double glazing sandwich helps to hold the internal pane of glass at a more comfortable temperature. This temperature differential is sufficient to prevent water vapour from hitting dew point and creating condensation on the bottle.

If you’re thinking of upgrading your windows, we can help you in double glazing watford & double glazing north london and other areas too. All our windows are bespoke made from a range of different glass products. If you have an extra cold room that doesn't get light, a room that gets too much sun, or a bedroom facing a noisy road – we can make the perfect window for you.