What Makes A Window Energy Efficient?
We have written on the anatomy of a window, but what makes a window Energy Efficient?What factors contribute to a window’s energy efficiency? Let’s get into some commonly used jargon so to give you a better understanding of what to look for and ask the window installation company you choose to do the work.
Glazing simply refers to the glass of the window itself. We use the words double-glazing and triple-glazing to refer to windows with 2 and 3 glass panes respectively. The days when people used windows with a single glass pane are long gone. Nowadays, any energy efficient window is at least double glazed. All things considered, a triple glazed window is more energy efficient than a double-glazed window. But, most of the energy efficiency does not result from just the presence of more layers of glass; it results from other factors like the gas-filling used in between the panes, and a Low-E film coating.
In double-glazing and triple-glazing windows, an inert gas is used to fill in the space between the glass panes. The reason is that inert gases are bad conductors of heat, and they help in slowing down the rate of heat transfer through the window – which means better insulating properties (this will pull down the U-factor mentioned in the previous blog post). These gases also help in noise isolation.
Typically, Argon is the gas used. Some manufacturers use a mixture of 2 or more inert gases for better results, which is more expensive, but saves costs in the long run.
Low emissivity coatings are basically very thin films applied on the window glass, which significantly improves its insulating ability. Let us briefly understand how Low-E films work.
Emissivity is the ability of a material to radiate heat that is incident on it, i.e. the heat incident on the material is first absorbed by it and then re-radiated. Whereas reflectivity refers to the ability of the material to bounce back the heat incident on it. Window glasses by nature have high thermal emissivity, which means that the heat incident on the window gets transferred through radiation. When a low-emissivity coating is applied to the window glass, it will then reflect more heat. So heat transfer through the window is reduced. However, while these coatings reduce the amount of heat transfer, the amount of visible light that can be transmitted through the window is not reduced, meaning you won’t compromise on brightness.
Window Frames and Energy Efficiency
By this point, you’re probably aware that anything that’s a bad conductor of heat makes for good window material because of its insulating properties. Naturally, that’s the case with window frames as well.
Therefore, the best possible frame materials, from an energy efficiency point of view, are Wood or reinforced Vinyl (vinyl frames reinforced with metal rods for strength). They have good insulating capability. But the best bet would be reinforced Vinyl window frames, because of the additional benefits they provide along with energy efficiency – they’re sturdy, require minimal maintenance, and are reasonably priced.
On the other hand, wooden frames have a great look, but they need a lot of maintenance, and are prone to rotting and other types of damage.
There are some other kinds of frame material as well, like Aluminium, Fiberglass/Composite, standard Vinyl, Aluminium-clad-wooden frames, each with their own advantages/disadvantages.
Metroplex Windows & Glass is committed to helping you find the perfect Dallas energy efficient replacement windows for your home or business. Contact our professionals and let is help you discover the best choice for for your style and your budget.