The components of a more efficient window are: welding, foam fill and the types of glass used. Double pane Low-E glass with argon gas is the first line of upgrade. The most efficient glass is triple pane low-E with krypton gas. All windows are rated with a U value to determine their efficiency.
Every window has an Energy Star label. The top left hand corner of the sticker is the windows U value. This number is the only criteria for accepetance into the Energy Star program. To convert the U value into an R rating, this is the formula. R = 1/u. This R rating is the same system used to evaluate insulation.
In 2015, the qualifications for the Energy Star program increased from a R 3 to an R 3.75. In order to have the Energy Star label, the window must be at least rated at an R 3.75.
Windows that have achieved an R 5 or better rating receive the "most efficient" qualification. Vinyl windows can achieve a R 5.88 rating whereas most wood windows are not able to achieve even a R 4 efficiency rating. This is the way for the Energy Star program to recognize the superior efficiency performance of vinyl windows yet allow the wood window industry to still qualify for the Energy Star program.
While vinyl windows have been considered lesser quality than wood windows in the past, today's technologies have turned the table. Vinyl windows are not only much more efficient, the industry has advanced the beauty and performance by offering a multitude of options. Such as: wood graining, miter formed edges, wood style grid options and infinite number of color choices.
No. Since the Energy Star label is on the window, you know the efficiency of the window without a full demonstration. The Energy Star label has acted as our own industry "consumer reports" performed by the NFRC.org, an independent testing organization for Energy Star.
We all know Anderson and Marvin. These companies have built their reputation nationally in the new construction industry. Vinyl windows traditionally are regional operations. Interestingly the vinyl window manufacturers have been in this market for many years and the wood manufacturers are actually newcomers to the replacement market.
With Get Clear Windows LLC we strive to give you the most value for all levels of window. Always choose the best window that your budget allows.