5 Factors That Determine the Level of Energy Efficiency of Replacement Windows for the Home 

Installing Energy Efficient Windows

When shopping for replacement windows for your home, there are many factors that must be considered. These include the types of windows that are available, the number of glass panes contained in each, and how certain windows will contribute to the overall value of your home.

In addition to this, you must consider the performance ratings associated with the windows. These reflect a measurement of the overall efficiency of the window.

There are 5 factors that determine the overall level of energy efficiency. These are outlined below, along with a brief explanation of each:

The U-Factor 

The U-Factor is a type of measurement that gauges the overall rate of heat loss of a window. The higher level that heat is resisted, the better the window serves as an insulative measure.

All components of the window go into determining the U-Factor. This includes the window frame, the glass used in the frame, and any spacers. I

f the U-Factor is a high number, it means the window has a poor level of energy efficiency. If it is a low number, it means the window will perform optimally and help conserve energy.

Frame materials such as wood, fiberglass, and vinyl are excellent contributors to the U-Factor; whereas, aluminum is not. 

The Solar Heat Gain Coefficient 

The solar heat gain coefficient – also referred to as the “SHGC” – specifies the amount of solar-based radiation that a replacement window allows to move to the interior of the home.

It ranges from the number 0 to the number 1. The lower the number, the better. This indicates that less solar radiation is transmitted from the exterior of the home to the interior of the home. 

The Visible Transmittance (VT)

The visible transmittance is also referred to as the “visible light transmittance” or “VLT”. In short, this outlines how much light the window allows to move into the interior of the home. This is also measured in terms of 0-1.

The higher number indicates more light will make its way inside the home and the lower the number, the less light. The glass, the number of glass panes, and the type of coatings used on replacement windows all play a role in determining the VT.

For performance windows, you will want to select those that have a VT level of 70% or higher. 

Air Leakage (AL) 

The heat loss and the heat gain of replacement windows occur through any type of infiltration that occurs as a result of assembly cracks. By choosing a window with a lower number, it means that less air will succeed at infiltrating the product.

A high number means that more air will infiltration the product. If this occurs, the interior humidity of your home will increase. That means more moisture will be inside of the home. This moisture could result to structural integrity compromises and even health problems among residents. 

Condensation Resistance (CR) 

The condensation resistance gauges how the window is able to resist the formation of moisture on the interior side of the glass. These levels range from as low as 0 to as high as 100. If the CR is low, you will find that the replacement window has a higher level of condensation accumulation.

Naturally, this moisture could result in the growth of mold, discoloration, and compromises to the structural integrity of the home. 

Contact Us Today 

We here at Southern Industries Home Improvements can assist you in determining the performance ratings of the replacement windows you are interested in having installed in your home. We encourage you to contact us today. When you do, be sure to inquire about our current low-cost installation: (833) 240-4900


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