There are numerous benefits to installing new, energy-efficient double or triple-glazed windows. However, one of the drawbacks is the emergence of condensation forming on the external glass. This is a particular issue in the UK’s changeable climate.
But why does condensation form? And how can we stop it?
In a nutshell, condensation is water vapour that condenses on the more humid side of a surface. With windows, this can be the inside or outside of the glass or even between the panes.
In this blog, we’ll further explain why condensation forms on your outer windows and outline some of the measures you can take to eliminate or reduce the problem.
What Causes Condensation?
Condensation forms when an object (such as a glass window) reaches its ‘dew point temperature’, with water vapour from the air condensing on the surface.
The dew point temperature is when the maximum amount of water vapour is achieved, known as saturation or 100% relative humidity. The dew point temperature can’t be higher than the air temperature. The dew point temperature varies depending on humidity and air pressure.
Understanding External Condensation
Whereas condensation on the inside of your windows is a sign that your windows may not be functioning properly, external condensation can mean the opposite.
Some new double and triple-glazed windows are so effective at retaining heat in the home that condensation appears on the outer pane of glass. The low-emissivity inner panes of glass stop heat from travelling out and warming the outer panes, so the temperature of the outer glass stays below the external dew point temperature.
This condensation usually occurs most clearly in the centre of the glass, becoming less visible closer to the insulated frame.
Some external condensation is natural during the summer months, as it is humid outside, and your house may be cool until the sun warms it through. This condensation typically occurs in the morning and should clear up by midday as the sun evaporates the water vapour.
However, if condensation persists, you may have an internal humidity issue.
If you see condensation between the panes of your double or triple glazing, it usually means that the airtight seal has broken, enabling water droplets to form when the hot air hits the space between the glass panes. The good news is, as long as it’s not a big crack, resealing the window is a relatively quick and low-cost fix. If the windows are still within their warranty, you should not have to pay for the seal repair.
How to Prevent Condensation on Windows
A natural phenomenon it may be, but it’s still a nuisance. External condensation can obscure your view and even cause damage to, particularly timber and UPVC windows, over time.
Wooden frames can warp or crack if alternating damp and hot sun. UPVC, while hardwearing and weather-resistant in a stable climate, expands and contracts, eventually cracking with regular exposure to dampness and intense heat. Both types of frames are also susceptible to limescale and mould in these circumstances.
If it persists, there are a few things you can do:
- Treat your windows with a water repellent – this will stop the water vapour gathering on the surface and cause it to run off
- Cut back any nearby foliage that could be dripping and contributing to the moisture it will also ensemble the sun to reach the window faster
- Increase the temperature inside your home – eg turn off your air conditioning for part of the day to help balance the interior and exterior temperature
- Infrared heating can also help eliminate external condensation but is a much pricier solution to what is usually a minor inconvenience
External condensation is largely only an aesthetic issue, but if it happens more frequently than is normal, it can also point to a high humidity problem within the home. If you think this is the case, you can hire a home inspector to check where the moisture is coming from.
Internal condensation is a different issue, potentially causing serious damage and health problems. We have gathered some tips and tricks for reducing condensation in your home in a previous blog.
Conclusion
Condensation on the outside of windows is a common complaint from homeowners, but in most cases, it is nothing to worry about. We hope this blog has set your mind at ease and given you some tips on dealing with condensation on your external windows.
Get In Touch Today
At Manchester Window Factory, we are experts in providing and installing the highest quality UPVC, aluminium and timber windows. We can talk you through your options and offer a free, no-obligation quote for your consideration. We also offer a pay monthly scheme to help you spread the cost. If you would like further information on any of our products or services, please don’t hesitate to get in touch.
We look forward to hearing from you!
