If you're like 90 percent of Americans, you're familiar with the ENERGY STAR label. If you're like 75 percent of Americans, the ENERGY STAR label influences your purchasing decisions. But what is ENERGY STAR and why is it so important? Today we'll delve into the history of the now-ubiquitous badge of energy efficiency and the criteria windows and doors must meet to earn it.
The history of ENERGY STAR
ENERGY STAR is an initiative of the Environmental Protection Agency (EPA) to identify products that meet government standards for energy efficiency, part of a coordinated effort to drastically reduce greenhouse gas emissions. When the ENERGY STAR voluntary labeling program was first introduced in 1992, it only applied to computers and monitors, but since then it has come to encompass some 70,000 products across 75 residential and commercial categories (as of 2019). Of those, only about 3,000 (4 percent) garnered the ENERGY STAR "Most Efficient" designation for exemplary performance.
Throughout its history, ENERGY STAR has implemented a number of programs and resources to assist homebuilders, homeowners, and residential contractors — for both new construction and existing structures. ENERGY STAR new constructions in the single-family, multi-family, and manufactured home categories, on average, exceed building code standards for energy efficiency by 20 percent.
For current homeowners looking to improve their energy efficiency, check out the following:
- ENERGY STAR Home Advisor: self-assessment and customized recommendation tool
- ENERGY STAR Yardstick: learn how you measure up to similar homes in total energy consumption.
- Home Energy Knowledge Center: Find certified contractors, installers, and HVAC specialists.
How windows and doors earn good ENERGY STAR ratings
For a window or door to even be considered for the ENERGY STAR label, it must:
- Come from a certified ENERGY STAR partner manufacturer
- Pass the National Fenestration Rating Council's (NFRC) testing, certification, and verification process.
- Return from the NFRC with ratings that meet guidelines established by the EPA.
NFRC ratings include:
- U-Factor, a measure of insulation proficiency. Lower numbers mean less heat is being transferred between the inside and outside of the glazing, making it easier for your home to maintain a desirable temperature. Min: 0.20, Max: 1.20
- SHGC, meaning solar heat gain coefficient — this is the fraction of solar radiation the window allows to penetrate the glazing. In warmer climates, you'll want this number to be lower. In colder climates, it's okay if it's a little higher. Min: 0, Max: 1
- Visible transmittance, or how much of the visible spectrum of natural light admitted through the window. Higher numbers mean you won't have to spend as much on artificial lighting. Min: 0, Max: 1
- Air leakage through a window is a major energy waster, so seek out a product that is as airtight as possible. Min: 0.1, Max: 0.3
Optimal ENERGY STAR window ratings vary slightly by climate, especially in regard to SHGC. Hodges Windows and Doors services Northern Virginia and the D.C. Metro Area, which both fall within the NFRC's North-Central Climate Zone. Here, windows should have a U-Factor less than or equal to 0.30 and a SHGC less than or equal to 0.40.
Doors are evaluated according to their glazing level, or the percentage of total surface area that is glass. Opaque doors (no glass) should have a U-Factor less than or equal to 0.017, doors that are less than half glass should have a U-Factor and SHGC both less than or equal to 0.25, and doors that are more than half glass should follow the same climate-prescribed ranges as windows.
ENERGY STAR products that save the environment and save you money
All Hodges Windows and Doors suppliers are ENERGY STAR darlings, consistently rating high for energy-saving window features such as non-conductive framing materials, multiple panes with low-emissivity coatings, and non-reactive gas fills to maximize efficiency. This year we are especially proud to be associated with ProVia, winner of the 2020 ENERGY STAR Partner of the Year - Sustained Excellence Award. Thanks to ProVia and ENERGY STAR's thousands of other partners, American families and businesses have saved more than 4 trillion kilowatt-hours of electricity and reduced greenhouse gas emissions by 3.5 million metric tons since 1992.
These are savings that benefit both our bank accounts and our planet.