Fiberglass Window & Door Glass Options
Inline Fiberglass offers double- and triple-pane insulating glass configurations, IGMAC-certified glass units and a range of Low-E coating options. Our team can help you compare available glass packages and determine the appropriate configuration for your selected window series and project requirements.
Glass Plays a Major Role in How a Window Performs
The frame is only one part of a high-performing window. The glass package can have a significant effect on thermal comfort, energy efficiency, condensation resistance and the overall performance of the finished window.
Inline offers different glazing configurations and Low-E coatings to support a range of residential, commercial and high-performance projects. From everyday residential applications to projects with more demanding energy targets, the appropriate glass package should be selected alongside the window series, size, configuration and overall building requirements.
Choose the Right Glass Configuration for Your Project
Different projects place different demands on their windows. Inline offers both double- and triple-pane options across applicable product series, allowing the glazing package to be selected around the project’s performance requirements.
Double-Pane Glass
Double-pane insulating glass uses two panes of glass to create an insulated glass unit and can be an appropriate choice for many residential and commercial applications.
Available configurations can be paired with Low-E coatings to help address the project’s energy performance, solar control and comfort requirements. Depending on the window series and configuration, double-pane glass can provide a practical balance of thermal performance, natural light and overall project requirements.
Best suited for: Projects where a balanced combination of performance, application and project requirements is the priority.
Triple-Pane Glass
Triple-pane insulating glass adds a third pane and an additional insulating space to the glass unit, supporting higher levels of thermal performance.
Triple glazing can be particularly valuable for projects focused on improved thermal comfort, energy efficiency or high-performance building objectives. ENERGY STAR performance is available across Inline’s triple-glazed products, with select Inline series capable of meeting ENERGY STAR Most Efficient criteria when appropriately configured.
Best suited for: High-performance homes, demanding climates and projects where enhanced thermal performance is an important design objective.
Double- and triple-pane availability varies by Inline window series and configuration. Final glass packages, performance values and certification eligibility should always be confirmed for the specific product, unit size and project requirements.
Control More Than the Temperature
Low-emissivity—or Low-E—coatings help control how heat and solar energy move through a window. Inline offers several Low-E options, including 180, 272, 366 and i89, allowing the glass package to be selected around thermal performance, solar heat gain, daylight and overall building design.
Low-E 180
Higher Solar Heat Gain
Low-E 180 is designed to allow comparatively more solar heat through the glass while still providing Low-E performance. This can make it useful in applications where passive solar gain is desirable.
Cardinal classifies LoĒ-180 as its high solar gain glass option.
Consider for: Projects where higher solar heat gain is part of the glazing strategy.
Low-E 272
Balanced Solar Performance
Low-E 272 provides a balance between natural light, solar heat gain and insulating performance.
Cardinal categorizes LoĒ²-272 as a moderate solar gain product, making it an option for projects looking for a more balanced glazing approach.
Consider for: Applications requiring a balance of daylight, solar control and energy performance.
Low-E 366
Greater Solar Control
Low-E 366 is designed to provide stronger solar control, helping reduce the amount of solar heat entering through the glass while maintaining natural light.
Cardinal categorizes LoĒ³-366 as an ultimate solar control glass option.
Consider for: Projects where limiting unwanted solar heat gain is an important part of the glazing strategy.
Low-E i89
Room-Side Thermal Performance
Unlike the other coatings, i89 is designed for application to the room-side surface of an insulating glass unit and can be combined with other Low-E coatings to further improve insulating performance.
Cardinal identifies LoĒ-i89 specifically as a room-side U-factor efficiency option.
Consider for: Projects looking to enhance the insulating performance of an appropriate glass configuration.
Low-E Selection Note
The appropriate Low-E coating depends on more than the window itself. Building orientation, climate, window area, desired solar heat gain, glass configuration and project performance requirements can all influence the selection.
Inline can help confirm available Low-E configurations for the selected window series and project.
IGMAC-Certified Glass Units for Long-Term Performance
The insulating glass unit is a critical component of window performance. It influences energy efficiency, thermal comfort, condensation resistance and long-term durability.
All Inline products use IGMAC-certified insulating glass units. IGMAC certification provides an established quality framework for insulating glass units and supports reliable glass-unit performance across Inline’s fiberglass window and door systems.
Match the Glass Package to the Performance Goal
For projects with more demanding energy-performance requirements, glazing needs to be considered as part of the complete window system.
Inline offers ENERGY STAR performance across all triple-glazed products and select double-glazed products. Eligibility depends on the product, glass package and configuration, so the appropriate glazing specification should be confirmed for each project.
Select Inline products also carry PHIUS and PHI certifications for Passive House and high-performance applications. These certifications apply only to specific products and configurations, so glass selection should always be reviewed alongside the complete window system and applicable technical documentation.
What Should You Consider When Choosing Window Glass?
The right glass package depends on how the window needs to perform within the building. Thermal performance, solar heat gain, natural light, condensation resistance and project-specific requirements should all be considered alongside the selected window series and configuration.
Thermal Performance
The glass package plays an important role in controlling heat transfer through the window and supporting interior comfort throughout the year.
Solar Heat Gain
Different Low-E coatings allow different amounts of solar energy through the glass. The right level depends on climate, orientation and the overall building strategy.
Natural Light
Glass selection can influence how much visible light enters a space. Performance requirements should be balanced with daylight and architectural goals.
Condensation Resistance
The complete window and glass configuration can affect interior surface temperatures and condensation resistance, particularly in colder conditions.
Project Requirements
Energy targets, building codes, certification goals and project specifications may influence which glass packages are appropriate.
Window Series & Configuration
Not every glazing option is available with every Inline product. Unit size, operating style and window series all need to be considered before the final glass package is specified.
Selecting Your Glass Package
1. Start With the Project
Tell us whether you’re planning a replacement, renovation, custom home, commercial building or high-performance project.
2. Choose Your Window Series
Glass availability and performance can vary by window series, size and configuration.
3. Establish Your Performance Goals
Consider comfort, energy efficiency, solar control, natural light and any certification or project-specific requirements.
4. Compare Glass & Low-E Options
Inline can help you compare available double- or triple-pane packages and applicable Low-E coatings.
5. Confirm the Final Specification
Before ordering or specifying, confirm the complete glass package, product configuration and applicable performance documentation with Inline.
Common Questions About Fiberglass Window and Door Glass Options
Find clear answers to common questions about fiberglass window and door glass options.
Does Inline offer double- and triple-pane glass?
Yes. Double- and triple-pane insulating glass configurations are available across applicable Inline window series. Availability depends on the particular product, size and configuration.
What Low-E glass options does Inline offer?
Inline identifies Low-E 180, 272, 366 and i89 among its available coating options. The appropriate coating depends on the glass configuration and project performance requirements.
Is triple-pane glass always the better choice?
Not necessarily. Triple glazing can provide higher thermal performance, but the appropriate choice depends on the window series, climate, project goals, budget and required performance. Double glazing may be suitable for many applications.
Are Inline's glass units IGMAC certified?
Yes. All Inline products use IGMAC-certified insulating glass units.
Are Inline's triple-glazed windows ENERGY STAR rated?
ENERGY STAR performance is available across all Inline triple-glazed products and select double-glazed products. Eligibility depends on the product, glass package and configuration, so the appropriate glazing specification should be confirmed for each project.
Can Inline help me choose the right glass?
Yes. Glass selection should account for the window series, configuration and project performance requirements. Inline can help review the available glazing packages and provide applicable product information and technical documentation.
Find the Right Glass for Your Project
Whether you’re choosing windows for a home, commercial building or high-performance project, Inline can help you compare glass configurations, Low-E coatings and product-specific performance options.