Frequently Asked Questions About Energy Efficient Windows

Well-built replacement windows should be more than just beautiful and durable; they also have to be energy-efficient. Homeowners buying replacement windows for the first time find it difficult to make an informed decision during consultations with a window replacement contractor because of the technical terms and a vast number of options.

Here, we answer some of the most frequently asked questions about energy-efficient windows.

Why do my windows need to have two glass panes?

Energy-efficient replacement windows have to be well-insulated. The idea is to keep heat where it’s needed—outside during hot days, and inside during cold days. Glass, however, is a naturally conductive material, which makes windows with single-panel glass a freeway for heat loss. By installing two panels of glass separated by insulation at the edges and center, plus a layer of vacuum-sealed airspace in between, heat conduction is greatly reduced, making the window energy-efficient.

Why do you fill the window with gas? And is it dangerous?

The airspace between the glass panels can be optionally filled with an inert gas, which, in our replacement windows, is a custom argon gas blend. Argon is a colorless, odorless, non-toxic, and non-flammable gas that enhances insulation, and is perfectly safe in case it’s accidentally inhaled.

What is low-E glass?

Low-emissivity glass is coated with layers of almost-clear material that filters ultraviolet (UV) and infrared rays without compromising the amount of visible light that goes through your windows. UV rays cause fabrics and printed matter to fade while infrared rays is what makes sunlight hot, precisely why you wouldn’t like either getting into your home. Each Renewal by Andersen® window replacement unit is available with High-Performance™ Low-E4® glass options, which can filter UV rays up to 95% and infrared rays up to 74%.

I keep hearing about U-value and R-value. What are they? And is there a difference?

Replacement window consultants, printed literature, and ratings labels refer to both U- and R-values interchangeably. They both refer to heat transfer, except that U-value (or U-factor) measures heat transmittance, while R-value measures heat resistance, making them inversely proportional. Replacement windows with a low U-value will therefore have a high R-value.

Renewal by Andersen® of Atlanta serves homeowners in Atlanta and surrounding areas. Our representatives are happy to answer your questions about our energy-efficient replacement windows. Call us today at (866) 609-5033 or fill out our contact form to receive a free estimate.