How Efficient Can Window Replacement Units Be?

You might be weighing the costs of window replacement and asking yourself how efficient window replacement units can be.

While you may be aware of how much you spend on energy through your bills, most people don’t know just how much of that goes to heating and cooling. About 41% of recurrent energy bills go to air conditioning. If you are spending this amount on energy or even more, your windows may be part of the problem. Damaged windows affect insulation leading to higher heating and cooling costs.

So, if you are wondering when to get replacement windows, your energy expenditure may offer the clearest indication. Are you sitting there and wondering how efficient are the replacement units at decreasing your heating bills in the first place? Well, the efficiency of window replacement units will vary based on the type of window and the frame.

Single, Dual and Triple Glazing

Single-glazed windows are the simplest because they have just one layer of glass. These windows don’t often have too many issues; but over time, they can get damaged due to normal wear and tear. On the other hand, they do not provide any insulation for the rooms, which means you may spend a lot more on heating. There are however better options out there when it comes to energy efficiency. For instance, you may decide to upgrade your single glazed windows with dual-glazed ones.

They are more energy efficient and durable too. Dual glazed windows usually achieve energy efficiency by trapping air between the two layers of glass.  Air is a lousy conductor of heat.  This fact significantly reduces the amount of heat your home loses to the external environment.

However, it is essential to know that even dual-paned windows are prone to wear and tear. For example, the hermetic seal that traps the air will fail over time. This seal reduces the windows ability to catch air between the glasses. The good thing, however, is that the seal can easily be replaced without changing the entire window unit.

But, it takes a long time before such a replacement is needed. Usually, it takes about 15 to 20 years, which would be worth it considering the savings on energy you get with these types of windows.

There are also cases where additional insulation for frigid temperatures will be needed. Triple-glazed windows are ideal for such situations. This necessity is because they trap two layers of air between three layers of glass. Think of it as a better version of double glazed windows that is more energy efficient. The windows will, however, cost relatively more but they will undoubtedly be worth it especially in areas that experience extremely cold temperatures.

Additional options

There are some options to make sure that your new window units are efficient. First, make sure that the window replacement units are Energy Star certified.  Energy Star certified windows can save up to 12% on energy costs.

Other alternatives include low-E glass. These window replacement options feature a coating on the outside that blocks heat and UV light from the sunshine. This keeps the heat out while lowering cooling costs in the process. The opposite happens for homes in cold regions. In these areas, the coating is placed on the inside. This ensures that the heat is kept inside leading to lower heating costs.

However, to maximize the benefits of these units, there has to be effective insulation for the entire home, not just the windows. Some homeowners may also choose to add argon gas between the window glazing. This addition can further improve insulation. Installing argon is an added expense though.

Framing material

If you want to know when to get replacement windows, then you may also want to look at the frame and decide whether its time to upgrade or not. Different frames have different efficiency levels.

Aluminum frames, for example, are the least energy efficient because they hardly insulate the room. This inefficiency is because aluminum is a perfect conductor of heat and cold.

Wood frames, on the other hand, are very efficient, but they can be quite expensive. The best options in terms of energy efficiency are vinyl and fiberglass. Vinyl is cheaper compared to fiberglass.

The Bottom Line

The efficiency of window replacement units depends on the window design and the frame. However, in case you want to achieve full energy efficiency for your home, you may also want to consider adding insulation options.


Meet Dan: Dan Hatcher is a home services industry pro and owns When he’s not helping homeowners select the perfect windows, he’s an avid Houston Astros fan and you might catch him on the jumbo-tron doing the wave.

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