How ProVia provides the most energy-efficient windows


ProVia provides energy-efficient windows that best meet the weather conditions in your area. The technology in the windows includes the vinyl compound, the frame design, and specialized glass system that combines low-E and clear glass with an insulating gas, like argon or krypton.

Read below to find out how homeowners can find the best windows for their needs and what makes ProVia windows among the most energy-efficient windows on the market.

How windows are rated


Reviewing this section will help homeowners understand how to determine the best energy-efficient windows for their home.


The National Fenestration Rating Council, an independent, non-profit organization that establishes window, door and skylight energy performance ratings, helps homeowners compare products by the label that is applied to the products of participating suppliers. The NFRC label for doors provides information on the energy performance for five factors:

  • U-Factor – The insulating value of the entire door system. Lower numbers reflect better insulating value, with values generally ranging from 0.25 to 1.25.
  • Solar Heat Gain Coefficient (SHGC) – The amount of heat from the sun passing through the glass (if the door has glass). Lower numbers indicate glass is keeping heat from entering your home, with SHGC measured on a scale of 0 to 1.
  • Visible Transmittance – The amount of visible light passing through glass. Higher numbers indicate glass is allowing more light to enter your home. The visible transmittance is measured on a scale of 0 to 1.
  • Air Infiltration – Measures how much air enters or escapes through the door, with lower numbers indicating that less air enters or escapes.
  • Condensation Resistance – The amount of moisture it takes for glass to condensate when exposed to extreme interior and exterior temperature changes. Higher numbers indicate better resistance to condensation. The condensation resistance is rated on a scale of 0 to 100.

Homeowners seeking to compare the NFRC ratings of ProVia windows can find our energy-efficient windows in the NFRC’s Certified Products Directory.

Energy Star® Certification

ENERGY STAR, a government-funded program, provides simple, credible and unbiased energy-efficiency information about products available to U.S. consumers. To be an ENERGY STAR window, it must be:

  • Manufactured by an ENERGY STAR partner
  • Independently tested, certified and verified by the NFRC
  • Have NFRC ratings that meet strict energy-efficiency guidelines set by the U.S. Environmental Protection Agency (EPA).

  • When looking for an ENERGY STAR window, it’s important to consider the climate in which you live. The ENERGY STAR climate zones chart helps homeowners identify windows that best meet the energy-efficiency standards for their region.

The features that make ProVia windows among the best


The overall construction of ProVia’s windows, including the materials used, the design of the frame and the energy-efficiency enhancements to the glass all work together to provide homeowners durable windows that deliver the comfort they require and the energy cost-savings they want.

Window Frame

  • Low-maintenance vinyl, offering superior weatherability and color retention – Learn More
  • INNERGY® thermal reinforcement (Endure & Aspect windows)
    • 700 times the insulating value of aluminum
    • Better protection against staining caused by condensation
    • Better impact resistance compared to other thermal reinforcements
  • Graphite polystyrene rigid foam insulation (Aeris & Endure, and upgrade option on Aspect windows) within cavities of the window frame
    • Reflects radiant heat
    • Increases resistance to the flow of heat
    • Increases the R-value as the temperature outside drops
  • Weatherstripping on the frame and sash
    • Barrier fin weatherstripping provides an effective barrier against air, water, dust and noise, with resistance to abrasion
    • Bulb seals are closed cell compression seals that prevent water from penetrating the foam cell structure and provides a barrier that enhances weatherstripping’s sealing performance

Insulated Glass Unit

ProVia offers multiple “glass packages,” combinations of window glass construction, energy-efficient coatings and insulation, to provide varying levels of energy efficiency, in part, to meet ENERGY STAR standards for different regions. Here are the components that make up an insulated glass unit:

  • Low-E Glass – Special coatings that reflect infrared light, keeping your home warmer in the winter and cooler in the summer. These low-E coatings also reflect ultraviolet light, which helps protect interior furnishings from fading. ProVia offers additional UV-protective coatings as well, though these may not be good options for homeowners with house plants as additional UV coatings will block rays vital for plants.
  • Multiple Panes – Two panes of glass with an air or gas-filled space in the middle insulate much better than a single pane. And, three panes are better than two. ProVia offers glass packages with two and three panes.
  • Gas Fills – Energy-efficient argon or krypton gas between the panes. These odorless, colorless, non-toxic gases insulate better than air.
  • Super Spacer® – A warm edge spacer keeps the glass panes the correct distance apart. ProVia’s Super Spacer, a non-metallic, dual-seal insulating glass spacer, insulates the pane edges, reduces heat transfer through the window, and offers the lowest U-Factor among dual-seal systems. Super Spacer performed the best among other dual- and single-seal units in the world’s toughest IG (insulating glass) durability test.

The best options for energy-efficient windows


Choose the ComforTech glass package that meets ENERGY STAR’s Most Efficient Window Criteria for your climate zone.

The best options for energy-efficient windows

PROVIA ComforTech™ Glass Packages

ProVia’s glass packages, branded the ComforTech Warm Edge Glazing System, have acryonym monikers that help describe the differences among them. Each ComforTech product is rated by its R-Value and has passed stringent testing and is IG Certified to ensure seals are durable and will not leak. (The R-Value only reflects data for the center of the glass, while overall window energy efficiency is measured by the U-Factor.)


  • T – Triple Glazed (three panes)
  • D – Double Glazed (two panes)
  • L – Low E
  • C – Clear Glass
  • A – Argon Gas: Chemically inert to UV radiation, sunlight stable, non-corrosive, and non-toxic, making it the best choice for double-glazed glass packages
  • K – Krypton Gas: Inert to glass coatings, heat and spacers, has the lowest conductivity of any gas used and raises the inner glazing temperature. This gas performs well in small chambers, making it the best choice for triple-glazed glass packages.
  • E – Elevation (no gas)
  • UV – Ultraviolet
  • HC – Hard Coat

Options for every home


Isolated image of an Aeris™ double hung window with prairie-style grids, example of both wood and vinyl window materials; image in ProVia's best window brands comparison

Superior vinyl window exterior construction paired with a beautiful wood-clad interior.

Isolated image of one of ProVia's Endure™ double hung top rated vinyl windows with grids on the top pane; image in ProVia's best window brands comparison

Stunning energy efficiency and the most options for colors, glass and more.

Isolated image of one of ProVia's Aspect™ double hung top rated vinyl windows with grids on the top pane; image in ProVia's best window brands comparison

Excellent mid-range window with high energy efficiency and sturdy construction.

Isolated image of a white ecoLite™ double hung vinyl window with grids on the top pane; image in ProVia's best window brands comparison

The best option for homeowners seeking a white, all-vinyl, economy-class window.