What causes condensation on the outside of new windows?

One of the many reasons we replace the windows and doors in our home is for better energy efficiency.  Whether multi-chambered PVCu windows or thermally broken aluminium with polyamide materials, modern aluminium windows and doors are designed to be as energy efficient as possible.  At times you may see condensation on the outside of your new windows and doors.  What causes condensation on the outside of new windows and why does it happen?

condensation on the outside of new windows

Understanding condensation on the outside of double glazed windows.

Whether made from aluminium or PVCU, both types of modern replacement windows feature a frame design and materials that provide insulation for the entire window and prevent the cold from the outside transferring to the inside.  They also prevent the heat inside your home from escaping to the outside.

As well as advanced frames, the glass we use is also latest generation and specification working together with your window frames.  Our table explains the key differences between old and new windows and doors to help explain why you get condensation on the outside of new windows.

Old Windows and DoorsModern Windows and Doors
Single glass.Advanced Double or Triple Glazing.
No thermal insulation to the window frames.Multi-chamber PVCu or thermally insulated aluminium.
Basic double glazing with basic sealant and metal spacer bars.Warm-edge spacer bars and advanced seals.
No coatings to the glass.Sophisticated low-emissivity coatings.
Air space between the glass.Argon gas fill.
Do not meet current Building Regulation energy efficiency requirements.Meet or exceed current Building Regulations energy efficiency requirements.
Do not retain heat in the home.Retain more heat in the home.
Cold from the outside passes through the windows.Cold is prevented from passing through the windows.
More cold surfaces.Minimal cold surfaces.
Basic window seals.Advanced rubbers, woolpile or Q-Lon
Cold Spots on the inside of the home.Cold spots kept on the outside of the home.
Condensation on the inside of an inefficient window.Possible condensation on the outside of a modern window.
Basic fixing methods used.Modern fixing methods employed.

Therefore if we have replaced your old, inefficient and single glazed windows, or even those with first generation double glazing, your new windows are more advanced and better made than ever before.  All these features of your new windows make them highly energy efficient.

Condensation on the outside of new windows is normal.

Condensation on the outside of new windows does not mean they are faulty. It is simply the windows doing their job of keeping your home more energy efficient.

During the Autumnal and Winter months the phenomenon of condensation on the outside of your new windows and doors will be more frequent. Where previously the heat was escaping and the cold was entering your home, your advanced windows and doors are so good, the heat is staying in your home and the cold is being prevented from entering it.  The outside of your window is now colder than the glass or the window it replaced.

A great example is defrosting a frozen windscreen on a cold morning.  Your car heating is warming up the windscreen from the inside, the heat is passing through and defrosting it on the ouside.  An energy efficient window prevents the transfer of heat.

Helping you understand external and internal condensation.

Internal condensation is usually caused by how we live in our homes and the amount of moisture we create from cooking, heating, drying clothes inside and not ventilating our homes enough.  Often this is the cause of internal condensation and not just on windows and doors.

External condensation is the opposite, with moisture remaining on the outside and landing on the first cold spot it finds, in this case the outside of your windows.

Finally, if you see condensation between your panes of glass this means the sealed unit has failed and will need replacing.  This is common on very old double glazed windows.

Condensation on the outside of new windows means great performing windows.

Why not visit our showroom and let us show you all the features of our advanced windows and doors such as the glass spacer bars, frame insulation and glass coatings? This will help you understand  why condensation on the outside of new windows is normal.

Any condensation on the outside of your windows and doors will disappear as soon as the outside temperature starts to rise.  Your new energy-efficient windows are keeping your home warmer, more comfortable and more secure than ever before.