Andersen windows offer a wide range of energy-efficient glass coatings and other glass customization options.
Whether for a new build or replacement window project, glass type is an important part of the purchase decision. This guide walks through the different glass options available with Andersen products to help decision-making go smoothly! (Spoiler alert from our pros: the Low-e, dual pane window is a winning configuration that’s our bestseller with homeowners and contractors.)
Basic Glass Configurations
| Black | Dual-Pane Glass | Triple-Pane Glass |
| What it is | By far the most popular option for Andersen windows, dual-pane glass provides much better thermal performance than single-pane glass for homes in any climate. You can also add a "soft" Low-E glass coating to the inside of the insulated glass unit (IGU) to improve its energy efficiency. ates | Triple-pane glass keeps more heat inside and blocks cold air even better than dual-pane glass. It's ideal for homes in northern climates that experience long winters and consistently cold temperatures or if you’re located in an extremely noisy environment. Because there is another surface inside the insulated glass unit, triple-pane windows can be installed with up to two soft Low-E coatings. |
| Best for | All climates | Cold climates (where heating is the main concern); urban environments |
| Availability | All Andersen products | A-Series windows and patio doors, 400 Series patio doors, select 200 Series patio doors |
Types of Glass Coatings
Soft vs. Hard Glass Coatings
Andersen offers four “soft coating” options and one “hard coating.” Soft coatings are applied to the glass surface inside the IGU (insulated glass unit) — the space between the panes. A “hard coating” is applied to the outer surface of the interior glass pane. This hard coating can be used in combination with one or two soft coatings depending on whether the window has dual or triple-pane glass.
Low-E / Low-E4 Glass
Low-E is a bestseller at Ring’s End because it has the highest average performance across all categories with fewer trade-offs. Low-E/Low-E4 glass improves energy efficiency by reflecting heat indoors during winter and blocking solar heat in summer. It's ideal for regions with both hot and cold seasons, balancing comfort and energy savings year-round.
Availability: All Andersen products
Best for: Climates with four seasons
SmartSun Glass
SmartSun glass is similar to Low-E/Low-E4 glass, but it blocks more ultraviolet rays (up to 95% of UV rays) and further reduces solar heat gain — while limiting the loss of visible light transmitted through the glass. It's ideal for climates where UV protection and cooling efficiency are priorities but you still want to enjoy the sunlight. You can also pair SmartSun glass with HeatLock technology to minimize heat gain while improving insulation.
Availability: All Andersen products
Best for: Climates with four seasons
Sun Glass
Sun Glass has a stronger tint than SmartSun, blocking even more heat and helping reduce cooling costs by minimizing solar heat gain. It's an excellent choice for hot, southern climates and homes that get intense sun. Keep in mind that Sun Glass also lets in less sunlight, which is a tradeoff that may deter homeowners.
Availability: E-Series, A-Series, 400 Series, 200 Series and 100 Series products
Best for: Hot climates (where cooling is the main concern)
Experience Andersen Window Options for Yourself
PassiveSun Glass
PassiveSun glass is designed to capture and retain solar heat. It enhances energy efficiency by allowing more solar warmth into the home and reducing heating needs in winter. You can also combine PassiveSun glass with HeatLock technology, which will help insulate the home. Rooms with high sun exposure, especially southeast facing rooms, may get very warm in the summer.
Availability: All Andersen products
Best for: Cold climates (where heating is the main concern)
HeatLock Glass Hard Coating
In addition to Andersen’s four soft coating options, they also offer HeatLock, a hard coating applied to the outer surface of the interior glass pane. This coating reflects heat back into the room, improving insulation. It's primarily used in cold climates to retain heat during the winter. For maximum energy efficiency, you can also combine HeatLock with all of Andersen's soft coatings except Sun Glass.
Availability: Most Andersen products
Best for: Cold climates (where heating is the main concern)
Specialty Glass Options
Privacy Glass
Privacy glass is designed to obscure visibility while still allowing light to pass through. It's often used in bathrooms or alongside entry doors. Andersen offers the following privacy glass patterns:
Cascade
Reed
Obscure
Fern
Satin-etched
Note that Andersen's HeatLock coating cannot be installed on windows with patterned glass.
Safety Glass
Tempered safety glass is heat-treated to increase its strength, and it shatters into small, less harmful pieces if broken. It's used in locations where safety is a concern, such as on patio doors. Tempered glass is often required by code when the window is 18 inches or less off the ground or located in a stairwell.
Laminated Glass
Laminated glass consists of layers of glass bonded together with an interlayer of vinyl. This interlayer holds the glass together so that the shards don't scatter even if the window breaks. Laminated, impact-resistant glass is often used in windows and doors in hurricane-prone regions.
Sound-Reducing Glass
This specialty glass minimizes noise transmission through windows and doors. It's typically used in homes near busy streets, and it can be paired with Low-E, SmartSun, or HeatLock coatings. Sound-reducing glass is an add-on option to A, 400, and 200 series windows.
Art Glass
Art glass features decorative colors and designs. These windows are often incorporated in entryways or as accent windows that add character to a space. Andersen's wide selection of glass patterns complements historic or modern homes, and homeowners can either choose from standard color palettes or customize their own.
Performance Ratings Guide
Looking for more technical details on the performance data for Andersen window glass coatings? Here are the specifications on each option. See glossary below for information on relevant terms.
| Andersen Performance Ratings Guide | |||||
| Glass Coating | U-Factor | SHGC | VLT | LSG | Climate |
| Low-E/Low-E4 | 0.27 to 0.30 | 0.41 - 0.42 | 66% - 73% | 1.58 - 1.76 | Four seasons |
| SmartSun | 0.24 - 0.27 | 0.25 - 0.27 | 56% - 66% | 2.07 - 2.64 | Four seasons |
| Sun Glass | 0.28 - 0.30 | 0.18 | 39% - 40% | 2.17 - 2.22 | Hot |
| PassiveSun | 0.29 - 0.31 | 0.62 - 0.70 | 77% - 80% | 1.10 - 1.29 | Cold |
| Low-E4 + HeatLock | 0.26 - 0.29 | 0.36 - 0.41 | 62% - 71% | 1.63 - 1.76 | Cold |
| PassiveSun + HeatLock | 0.28 - 0.30 | 0.62 - 0.64 | 75% - 78% | 1.15 - 1.24 | Very Cold |
* Approximate values from Andersen A-Series, 400 Series, 200 Series, and 100 Series products, center of glass performance only. Numbers will vary depending on specific product configurations. For precise specifications, refer to Andersen’s technical documents. For summary of performance by type, see Andersen’s performance summary.
Window Energy Efficiency and Performance Terms
U-Factor: Measures how well a window prevents heat from escaping — lower numbers mean better insulation. Learn more in our Guide to U-Factor and R-Value.
Solar Heat Gain Coefficient (SHGC): Indicates how much heat from the sun is allowed through a window — lower numbers mean less heat enters.
Visible Light Transmittance (VLT): Represents the amount of visible light that passes through a window — higher numbers mean more natural light.
Light to Solar Gain (LSG): The ratio of VLT to SHGC, indicating how well a window provides daylight while minimizing heat gain — higher values are better for balancing light and heat control.
For performance ratings on each product in Andersen’s series, please reference the performance guides below:
- 100 Series Product Performance
- 200 Series Product Performance
- 400 Series Product Performance
- A-Series Product Performance
Discuss Your Project with the Andersen Experts at Ring’s End
As a window supplier and installer in the Northeast, the window team at Ring’s End knows the importance of installing windows that perform well in harsh winters and hot summers.
Andersen Windows and Doors offers our customers a wide range of quality options that accommodate all types of project needs, and we’re proud to be an authorized Andersen dealer. Visit one of our eight showrooms to experience Andersen windows for yourself and talk with our window specialists in person.
Do you live in Connecticut, Westchester County, NY, or South County, RI? We offer a 100% free on-site or in-home consultation to help plan and price the window installation project. One of our window experts will work with you to evaluate the project, inspect windows, identify problems, and provide design options tailored to the home.