Have you felt the sun through your Low-E glass windows even in the winter? This occurs because Low-E glass lets selective heat through windows. In this blog, we’ll dive deeper to explain why.

According to the American Energy Innovation Council, Low-E glass windows can offer substantial energy savings by reducing heat loss up to 70%. Homeowners can save hundreds of dollars annually by switching to energy-efficient windows with Low-E glass. 

But why exactly do Low-E glass windows allow sun through in the winter, and how do they help keep your home warm? Let’s dive in.

What is Low-E Glass?

Low-E glass stands for low-emissivity glass, a type of glass that has a thin, transparent coating that improves performance. Low-E glass can help keep your home comfortable with industry-leading insulation and improved energy efficiency.

How Low-E Glass Works

Low-E glass windows reduce the amount of heat that passes through by reflecting infrared heat. The transparent coating on the windows helps reduce the amount of heat that passes through. 

In turn, this means they keep heat inside during the winter and block heat from entering in the summer. Low-E glass windows allow visible light from the sun into your home while reflecting long-wave infrared radiation into your home. 

The heat from the sun is short-wave infrared radiation (solar heat). A window’s Solar Heat Gain Coefficient (SHGC) measures how much solar radiation enters through it. A window with a lower SHGC will block more heat with a thicker coating of Low-E than a window with a higher SHGC that blocks less heat.

Why You Feel the Sun Through Low-E in the Winter

Depending on the climate where you live, your Low-E coating may let more or less solar heat through. In colder climates, houses facing north, or those surrounded by trees, ENERGY STAR® recommends a higher solar heat gain coefficient (SHGC). This allows for some natural heating in your home that comes from the warmth of the sun. The selective coating of Low-E glass windows allows light through but reflects infrared heat.

In the wintertime, this type of window allows visible sunlight to come through while reducing heat loss and keeping heat inside your home. Feeling the sun through your Low-E glass windows actually reflects that the windows are functioning properly, allowing solar warmth to pass through. This type of ENERGY-STAR-certified window has a lower SHGC that keeps the heat where you want it (inside your home) to help you cut down on monthly energy bills.

Choosing Energy Efficient Replacement Windows 

Are you considering replacing the windows in your home? Upgrading to ENERGY STAR-certified windows can help cut down on your monthly costs. There are a variety of SoftLife windows and doors that offer Low-E Glass to keep your home warmer throughout the winter. Find a SoftLite dealer near you for energy-efficient replacement windows.