Frequently Asked Questions About Energy Efficiency
We've taken the questions we most often hear from homeowners like you regarding energy efficiency and had our engineers and experts answer themto help you learn more about how windows and doors can affect energy efficiency.
QUESTIONS ABOUT ENERGY EFFICIENCY
- What makes a window or door energy efficient?
- What is an R-value and how important is it in selecting windows?
- What is a U-Factor?
- What is Low-E and, how important is it to have it on your windows or doors?
- What is ENERGY STAR®and what does it have to do with windows and doors?
- What is the NFRC and what should I know about it?
- Does argon or krypton gas between glass panes really make a difference in energy efficiency?
- How important is weather stripping?
- What are the different types of weather stripping, and what benefits do each have?
- Is there a way to improve the energy efficiency of existing (prime) windows that are still in good condition but have just a single pane of glass?
What makes a window or door energy efficient?
Numerous factors, including how the frame and sashes are engineered and built, the type of glass used (single-, double- or triple-pane), the weather stripping, the type of low-emissivity coating on the glass and the presence of argon or krypton gas.
What is an R-value and how important is it in selecting windows?
Although the U-Factor is actually the important number in evaluating windows and doors today, most people are more familiar with the related concept of R-value (or R-factor). The R-factor of a window is the measure of its resistance to the transfer of heat flow. The higher its R-value, the greater its insulating ability.
What is a U-Factor?
U-Factor (or U-value) is the measure of the window's ability to conduct heatin other words, the amount of heat transmitted through the window. The lower a window's U-Factor, the better the window is at insulating your home.
What is Low-E and, how important is it to have it on your windows or doors?
Low-E stands for low emissivity and is a fairly new advancement in glass technology. Basically, it's a microscopic, metallic coatingapplied to a surface of glassthat reflects and re-radiates heat energy either into or out of a home depending on climate conditions. Using Low- E is an excellent way to increase the energy efficiency of a window. In fact, it's so effective that every Soft-Lite Gorell window with Low-E is ENERGY STAR®-compliant in every region of the U.S.
What is ENERGY STAR®and what does it have to do with windows and doors?
ENERGY STAR is a U.S. government programadministered by the Department of Energy and the Environmental Protection Agency with the cooperation of manufacturersthat's designed to reduce the consumption of fossil fuels through the education of consumers. The program covers many different types of products. Windows and doors can only carry the ENERGY STAR label if they are tested by an independent laboratory through the NFRC program and meet specific, predetermined U-Factor ratings. By selecting ENERGY STAR products, you will reduce your energy costs and help make the environment cleaner.
What is the NFRC and what should I know about it?
NFRC stands for the National Fenestration Rating Council. It's a program established by the U.S. Department of Energy to help consumers compare window products and options. Window manufacturers participating in the program are required to label every window to its specific thermal performance level. Customers are then ensured that the products they select meet the requirements for their application. Participation in the NFRC program is voluntary. Not all manufacturers participate because it requires outside third party inspection and extensive product testing. Soft-Lite Gorell IS a participant in the NFRC program.
Does argon or krypton gas between glass panes really make a difference in energy efficiency?
For air to insulate well, it needs to be as still as possible because moving air carries energy. Both argon and krypton are heavier than airso they're less prone to convection or thermal movement. The bottom line is that heavier-than-air gases offer a higher level of insulation. Both argon and krypton are found naturally in the air you breathe and are completely harmless.
How important is weather stripping?
Very. Weather stripping is important because it provides the barrier against air and water in windows and doors. It is the only element of operating windows or doors that make them reasonably air tight. High-quality weather stripping that's applied and compressed properly really does improve the insulating performance of windows.
What are the different types of weather stripping, and what benefits do each have?
Although there are many different types of weather stripping, they basically fall into one of three categorieswoven piles, flaps, and hollow or foam bulbs. Which is best? That depends on the window style, design and application. Windows and doors that are expertly engineeredlike Soft-Lite Gorell'sare designed with weather stripping that creates the tightest possible seal and holds up to time and heavy use.
Is there a way to improve the energy efficiency of existing (prime) windows that are still in good condition but have just a single pane of glass?
High-quality, custom-built storm windows represent a practical way to improve the efficiency of existing windows that are in good condition. Be sure to choose only high-quality, custom-built storm products for your existing windows to ensure the tightest possible fit and to seal out the elements.