Wet windows every morning? There is a solution
If you're regularly wiping water from your windows on cold mornings, you're certainly not alone. Condensation is a common problem in New Zealand homes and can be particularly noticeable through the colder months in Dunedin, Otago and Southland.
Retrofitting your existing timber windows with double glazing can significantly reduce condensation on the glass. By keeping the inside surface of your windows warmer, double glazing reduces one of the main places moisture in the air turns back into water. The result can be noticeably warmer, drier windows and a more comfortable home through winter.
Why does condensation form on your windows?
There's always some moisture in the air inside your home. Everyday activities such as cooking, showering, washing and drying clothes – and even breathing – continually add more.
When that warm, moisture-laden air comes into contact with a cold surface, it cools. If the surface is cold enough, the moisture turns into the droplets of water we know as condensation.
Single-glazed windows are particularly prone to this because there's only one thin pane of glass separating the warmth inside your home from the cold outside.
Why it's such a problem during a southern winter
The colder it gets outside, the colder single-glazed windows become – and that can make condensation much more noticeable.
It can be particularly frustrating in older homes that are harder to keep consistently warm. You heat the room, but the glass remains a cold surface where moisture can continue to collect.
That water doesn't necessarily mean there's anything wrong with the window itself. The moisture is coming from inside your home; the cold glass is simply where you're seeing it.
How does double glazing reduce condensation?
This is where changing the glazing makes such a difference. Instead of a single pane of glass, double glazing has two panes separated by an insulating space. This slows the transfer of heat through the window and keeps the inside pane of glass considerably warmer than single glazing.
Because that surface stays warmer, moisture in the indoor air is less likely to condense when it reaches the window. Choosing higher-performing options such as Low-E glass and argon gas can improve the insulating performance further and provide even greater benefits for heat loss and condensation.
Keep the natural insulation of your timber windows
If your home already has timber windows, there's another advantage. Timber is a natural thermal insulator. Its cellular structure contains tiny air pockets that help create a barrier to heat and cold. Rather than removing your existing timber frames, Thermawood Otago can retain them, carry out any timber window restoration needed, and retrofit modern double glazing into the existing joinery. You're combining the natural insulating properties of timber with much better performing glass.
Thermawood also manages moisture around the double glazing
There's another moisture issue that's important when double glazing timber windows – and it's different from the condensation you see on the glass.
Moisture can find its way into the glazing rebate where the double-glazed unit sits within the timber. If water becomes trapped there, it can sit against both the timber and the sealed double-glazed unit. Over time, that can contribute to deterioration of the timber and failure of the glass unit.
The thermawood system patented design
The Thermawood system is specifically designed to give that moisture somewhere to go. The double glazing sits above a purpose-designed drainage system on a 15-degree slope. If water gets into the glazing rebate, it can drain beneath the bottom beading and out of the window rather than remaining trapped around the glass.
It's one of the important differences between the complete Thermawood system and simply fitting double-glazed glass into an existing timber window.
Double glazing is only part of creating a drier home
Double glazing tackles one of the most visible symptoms of excess moisture by making your internal glass warmer. But it doesn't remove moisture from the air itself.
There are some simple things you can do alongside your new double glazing to help keep your home drier:
- use extractor fans vented to the outside when cooking and showering
- vent clothes dryers outside and avoid drying washing indoors where possible
- keep rooms adequately heated and ventilated
- check for leaks and moisture underneath the house
- avoid unflued gas heaters, which release moisture into the indoor air.
Reducing the amount of moisture produced inside your home while improving the thermal performance of your windows gives you the best chance of getting condensation under control. Find out more about condensation here.
Condensation on the outside of the glass can actually indicate that your double glazing is insulating effectively. Because less heat is escaping from inside your home, the external pane can remain cold enough for moisture in the outdoor air to condense on it. It will normally disappear as the outside temperature rises.
It shouldn’t. Condensation or fogging between the panes usually indicates that the seal around the insulated glass unit has failed and moisture has entered the space between the glass. Thermawood developed its drainage system specifically to prevent water sitting around the edge of the double-glazed unit, helping protect it from the conditions that can contribute to failure.
The amount of condensation can vary according to how much moisture is produced in the room, its temperature, ventilation and how cold the window surface becomes. Bathrooms, kitchens and bedrooms can therefore behave quite differently, even within the same house.
Yes. The type of double glazing you choose can make a difference to thermal performance and condensation reduction. Thermawood Otago offers different glazing options, including Low-E glass, and can recommend the most suitable combination for your home. Their highest-performing Low-E option is specifically promoted for optimal insulation with minimal condensation.
Because an unflued gas heater releases water vapour from combustion directly into the room. That adds even more moisture to the indoor air, which can increase condensation on cold surfaces. Thermawood's condensation guidance specifically recommends avoiding unflued LPG heaters when trying to reduce moisture inside the home.
The new windows also eliminated all of the condensation
"It has been over 2 years since we had our widows retrofitted and double glazed by Thermawood. We instantly noticed how much warmer the house was and the way the windows reduced street noise. The new windows also eliminated all of the condensation that used to build up on the windows we had replaced. The windows have continued to perform well, and we have had no issues with the windows since their installation. Could not recommend them more!"
J Loehr
No condensation now and the lounge feels so much warmer
"We are so so happy with our lounge retrofitted wooden doubleglazed windows - the guys were absolutely awesome - so lovely and professional. Can't speak highly enough of these guys and Thermawood - would highly recommend them. No condensation now and the lounge feels so much warmer. Thanks to the whole team from quote to installation - very professional!"
L Morrison