Windows are the number one area where temperature transfers occur in homes and buildings. This is partly because older windows are typically not insulated and may only have one pane of glass, making them drafty and uncomfortable. The good news is that modern windows are energy-efficient and insulated, and they do make a difference when it comes to your heating and cooling bills! Let’s take a look at the intricacies of insulated windows.
Anatomy of Insulated Windows
Insulated windows have a low SHGC, a high R-Value, and a low U-value, but what are these terms, and how do they correlate to insulated windows?
- SHGC: Measures how much solar heat is transferred through the window. A lower value is better.
- R-Value: Represents the heat resistance of the window. A higher value is better.
- U-Value: A measure of how much heat escapes a particular room. A lower value is better.
Once you understand the values associated with insulated windows, it’s time to look at the components of an insulated window. These are the glass panes, framing materials, and gas fills. Attention to these components is critical to reduce energy usage and construct a passive building.
Insulated windows have two or three glass panes, often called window glazing. A single-glazed window has one pane and is not considered energy-efficient. A double-glazed window has two panes and is considered insulated and energy efficient. A triple-glazed window contains three panes of glass and is considered insulated and energy efficient.
The framing materials used to construct the windows are incredibly important. Good, solid materials can reduce air leaks and lower your heating and cooling bills. Traditional framing materials include wood, fiberglass, vinyl, and aluminum. Reynaers Aluminium offers aluminum-framed windows for maximum durability and energy efficiency. Not to mention, aluminum is considered an environmentally friendly material due to its high level of recyclability.
To add more insulation to a window, gas, usually krypton or argon, is used to fill the empty spaces between the panes. The gas remains inside the window due to the use of precisely placed and secured spacers. It’s important to note that regular air can be used to fill the spaces between the glass, but it is not as energy-efficient as krypton or argon, which are denser than air and help inhibit heat transfer better.
How Insulated Windows Work
There are a couple of truths when it comes to windows. All windows lose or gain a certain amount of heat via convection, conduction, and air seepage. When we talk about insulated windows, we are talking about those that seek to minimize these flaws to reduce drafts, thermal heating, and air loss from inside the building.
To be considered an insulated window, it must contain at least two panes of glass. Those panes of glass are then set a specific distance apart and hermetically sealed. This process lowers the SHGC and U-factor. When gas is used between the spaces, the thermal conductivity of the window is further reduced. This is because the sun’s energy hits the first pane of glass, warming it. However, when the heat tries to penetrate further, the density of the gas obstructs the flow. This means that the thermal conductivity of the window is minimized.
To further aid in the energy efficiency of the window, the frames can be insulated, and low-E coatings can help keep radiant heat from the sun out of the building in the summer while still allowing plenty of natural light.
Insulated Windows in Passive Home
Passive homes are designed to be highly energy efficient while still being comfortable and healthy to live in. To be a passive home, builders, architects, and homeowners must consider various factors during the building process. This includes the orientation of the building, the materials used, appliances, layout, and degree of solar shading by trees and other structures that may be nearby.
Creating a passive building that uses minimal energy also means attempting to prevent heat transfer from inside the building to the outside and vice versa. For that reason, many passive home builders and architects choose high-quality insulated doors and double or triple-pane windows that are insulated, hermetically sealed, and filled with dense gas. By installing high-quality insulated windows, passive homes experience less heat transfer through the windows and lower heating and cooling bills throughout their life cycle.
High-Insulating Windows With Reynaers Aluminium
At Reynaers Aluminium, we offer high-insulating, super high-insulating, and passive house aluminum and glass windows for commercial and residential buildings. We can even help recommend the right windows for the degree of energy efficiency you want for your new or existing building and show you the corresponding R- and U-values along with the SHGC rating.