Condensation in Double Glazing

Condensation is an age old problem that Finesse is used to dealing with on a daily basis and its intricacies have led us to develop and investigate solutions for our customers over the decades. It is a process where gas or vapour changes into a liquid and if the temperature of an object falls below ‘Dew point’ that liquid will collect on its surface. It can be seen on 3 areas of double glazing:

  1. On the internal pane
  2. Inside the unit itself
  3. On the outside pane

Internal pane:

This type of condensation can cause problems from pools of water on window sills to damp and mould growth. Modern homes are designed to be well insulated; therefore, we have created rooms with much less ventilation. All homes contain moisture that is generated by people doing normal everyday activities if that moisture cannot escape it will collect somewhere in the house. Just breathing in your home produces ½ litre of moisture per day!

Many people believe that having double glazing fitted will eradicate condensation and this is not strictly true. The treatments for condensation are ventilation and heating. Therefore at Finesse we always design our double glazed windows with customer’s experience of condensation in mind. If condensation has been a problem in the past the designer might consider including trickle vents in the new windows to provide ventilation. The other way to significantly reduce condensation is to install enhanced thermally insulating units.

  • Low Emissivity glass restricts heat exchange across the air space between the panes of glass, this also helps to keep the inner pane of glass warmer and less attractive to moisture.
  • Warm edge spacer bar is made of insulating material which reduces condensation at the edges.
  • Argon gas is injected into the cavity between the panes of glass; argon has 34% lower thermal conductivity than air so helps to keep warmth inside your home.
  • Insulating coating on the internal pane of glass reflects heat back into your room preventing heat loss.

Finesse provide this for our customers with all our A – rated units.

2. Condensation inside the panes of glass.

This is usually a sign that the unit is no longer completely sealed and that air is being allowed to creep into the cavity. Air will be penetrating the seal around the glass and visibility through the window will become reduced. There is no solution to this problem and it cannot be reversed, therefore the unit will need to be replaced. This is not a problem for Finesse customers as all our installations carry a 10 year guarantee.

3. Condensation on the outside pane of glass.

This is the type of condensation that you want to see because it means your unit is working very efficiently as heat reduction is actively being reduced from inside your home and is not the sign of a defective unit. This phenomenon occurs on days with certain atmospheric conditions which means that external condensation may form on some units and not others even if they are right next to each other! The coating on the inside pane of glass reflects heat from radiators and fires back into your room, therefore as the warm air has not been allowed to pass through your glass the warmth does not reach the outside pane of glass making it very cold and susceptible to collecting moisture. This type of condensation disappears as the day warms up and is no reason for concern.

If you have any further questions regarding insulation and how a Finesse window can help please do not hesitate to contact us.