You’ve probably heard a lot of people raving about the benefits of double glazed windows. If you’re not familiar with the term, it has nothing to do with sugar-coating. It’s simply pushing two layers of glass against each other and making benefit of the air trapped in-between to reduce heat and regulate energy consumption.
The fact that more than 25% of your home energy bill is wasted, as air escapes through inefficient windows and doors should give you a hint of how important these coatings are.
While many are well-acquainted with the benefits double glazing provides, only a few are aware of its mechanism; how it actually reduces heat loss. This will be our focus in this article.
Double Glazing Heat Loss Mechanics
The mechanics of that concept are summed up in how conduction works. For heat to be lost through your window, it’ll need a surface to get transferred or conducted through. Double-glazed windows are made out of two planes of glass with Argon gas in between them.
Argon is a poor conductor of heat. So the heat doesn’t really make it through to the opposite plane of glass, meaning that it’s not fully transferred to the other side of the window. The same thing happens with noise.
By installing double-glazed windows throughout your house, you could reduce the heat lost by a staggering 54% to 64%. This also translates into lower heating bills in the long run.
Now that we’ve discussed all the mechanics that play a role in reducing heat loss, we should discuss how these mechanics actually function.
The main thing double-glazed windows do in terms of reducing heat loss is control temperature. It keeps the inside temperature unaffected by the outside temperature and vice versa. This is due to the poor conduction quality of the structure that we just spoke about.
It controls the temperature keeping the cold areas cold and the warm ones warm without the need to use the heating or cooling systems to counter the effects of the outer temperature.
Another aspect that plays a role in the reduction of heat loss through double-glazed windows is the fact that the glass planes have a reflective e-coating.
The inner side of each glass plane is coated in a reflective material that reflects the temperature back to where it came from to further reduce heat loss. This, again, keeps the inside temperature unaffected by the outside temperature due to the added barrier that poorly conducts heat.
The Science Behind The Process
When molecules are heated they move quickly and conduct heat to each other. In the case of molecules trapped within a thin layer between two glass surfaces; molecules are tight and close to each other. This, in turn, allows for easier heat transfer.
On the other side, regular molecules that are spread widely in the air are far apart from each other, so they have much slower heat transferring rate. Hence, the thin layer of air of double glazed windows acts as a heat insulator.
In other words, making an extremely thin gap for air to prevent it from circulating properly results in lower heat conduction. So, it reduces the overall heat loss. Technically speaking, the heat loss is not avoided, it’s just slowed down.
It’s All About The ‘Spacer’
The gap between the 2 glass layers is called a spacer. It ranges from 6 to 20 mm and is usually made of fiber, metal, or Aluminum, in case you want to reduce condensation. Interestingly, this is the key to keeping your house cool in summer and warm in winter.
For energy efficiency, the spacer is usually 12 mm, which is considered good for both heat and acoustic insulation. But if you put reducing heat loss as your priority, you should opt for 16+ mm for better insulation.
Regarding the thickness of the glass itself, it can vary and it has nothing to do with the spacer. It mostly depends on the temperature of the area you live in.
Heat Loss vs. Radiant Heat
Does double glazing insulate hot temperatures completely?
This sounds too good to be true and it is. You must distinguish between reducing heat loss, which is basically trying to keep the temperature as it is, whether it’s cold or hot. And Radiant heat that comes from direct sunlight.
If sunlight directly hits your window, there’s no way to stop it. Double glazing won’t help with that. Using a UV light blocking window tint might help in such cases.
Should You Double-Glaze Your House?
So, the question beckons. Should you double-glaze your house and is it worth it?
It’s definitely something to consider, especially if you live somewhere cold like England. Instead of spending so much annually on heating systems in an effort to try and make your home feel warmer during winter, you could simply install double-glazed windows to your house.
Double-glazed windows definitely cost more than regular windows do, but when compared to the costs you’ll be saving up in the long run, the one time cost of double-glazing seems less steep.
It’s estimated that you save from 10% to 15% of your annual energy bills when you have double-glazed windows as opposed to regular ones. Not to mention that the life of one of these windows is expected to last for over 35 years, so if you do the math and distribute the cost of installing double-glazed windows in comparison to the annual energy costs you’ll be saving, it seems like a more-than-fair bargain.
To make matters easier, you don’t necessarily have to go through the hassle of removing existing windows in order to install your new double-glazed ones. You could actually double-glaze existing windows.
How to double-glaze existing windows and cut costs even further
There are two main ways to double-glaze an existing window. One of them is to fit a sub-frame on the inside of your window and then fit an optical-grade acrylic panel within that frame. This type of set-up is held together by continuous channels of magnets that provide an air-tight seal to your existing window turning it into a double-glazed window.
Another way to do that is to simply fit a second panel onto a separate frame molded on the inside of your existing windows to create a slightly bulkier double-glazed window.
Other Benefits of Double Glazing
People usually double-glaze their homes in order to prevent heat loss but there are other benefits too. Here are some of the reasons people opt to double-glaze their houses:
They’re more energy efficient
Since double-glazed windows reduce heat loss and maintain the interior temperature of your home to a certain extent, they cut costs on energy bills. You’ll have to spend less on heaters – or coolers – since you’ll be reducing the heat transferred into and outside of your home.
They brighten up your home without making it feel cold
Windows make any home look more alive; they let in more light and make your space feel more open. Unfortunately though, in colder countries, people usually hesitate to build large windows into their homes in fear of feeling cold during winter. Fortunately, double-glazed windows solve this issue since they provide all the benefits of a window without bringing in the drawbacks of having a colder space during cold weather.
They’re safer and stronger
Double-glazed windows are also actually stronger than regular windows since they are dual-layered. The glass itself is much stronger making the whole window much safer than a regular window.
They give you a quieter home
Not to mention, since double-glazed windows have a gap in between their layers, they also reduce noise transfer. Having double-glazed windows will help you have a quieter home, unaffected by outside noises.