Low-E Glass vs Spandrel Glass: Which Is Better?

September 22, 2024

Key Takeaways

Low-E glass is energy efficient and controls heat and UV light – ideal for areas where visibility is needed.
Spandrel glass is used to conceal building features and has an opaque finish, perfect for creating uniform facades.
While Low-E glass can help lower energy costs, spandrel glass tends to be more cost-effective to install.
Both glass types have specific installation and maintenance requirements, with Low-E glass needing more careful handling.
The choice between Low-E and Spandrel glass should be based on the specific needs and aesthetic goals of your project – and at Panda, we’ll help you make the right choice of glass for your commercial or residential projects.

What is Low-E Glass

Low-E glass is a type of glass that has been coated with microscopic layers of metallic oxides. This invisible coat is designed to minimize the amount of ultraviolet and infrared light that can pass through glass without compromising the amount of visible light that’s transmitted.

An image which shows how low-e glass works.

This coating reflects interior temperatures back inside, keeping your space warm during cold months. During hot months, it does the opposite by reflecting exterior heat away from your windows, keeping your space cooler (image courtesy of Energy Education).

Advantages of Low-E Glass

Energy savings: By reflecting heat back to its source, Low-E glass can significantly reduce energy bills.
UV protection: It blocks most of the harmful UV rays that can fade furniture and floors.
Comfort: It reduces temperature fluctuations, making your living or working space more comfortable.

Disadvantages of Low-E Glass

However, low-E glass tends to cost more than regular or annealed glass, and the installation process requires expertise to avoid damaging the coatings. Also, if not properly selected, the coatings can affect the color perception of the natural light entering the space.

Founded in 1991, Panda Windows & Doors specializes in state-of-the-art custom glass wall systems for both residential and commercial spaces through Panda Windows & Doors. Operating from our manufacturing facility in Las Vegas, Nevada, we have been at the forefront of innovation for over 30 years. Our extensive product lineup includes over 80 high-end offerings, such as pivot doors, French doors, folding doors, lift & slides, multi-slides, horizontal sliding walls, and operable windows. These systems are available in materials like aluminum, steel, stainless steel, bronze, solid wood, and aluminum-wood clad.

We are renowned for our award-winning designs, engineering solutions, and fast lead times, delivering in just 6-10 weeks to customers throughout the U.S. and Caribbean. Trusted by leading architectural firms and glaziers nationwide, we stand as the premier manufacturer of custom luxury windows and doors in the United States.

Explore Custom Solutions from Panda Windows & Doors Today

What is Spandrel Glass

Spandrel glass is a type of architectural glass used to cover and protect building features that are not visually appealing. It is typically found between floors of a building, hiding things like construction materials, structural elements, floor slabs, columns, insulation, and HVAC systems – providing a sleek, uniform look to the exterior of a building.

The way Spandrel glass works is simple: it has an opaque coating that blocks the view. It can be back-painted, ceramic frit, or have a reflective coating, depending on the desired effect and performance requirements. In the image above, the spandrel glass is the one that is fully opaque and gray in color (image courtesy of Glass Magazine).

Advantages of Spandrel Glass

Allows architects to achieve a clean, seamless appearance on the building exterior by hiding structural elements.
Can be customized in a variety of colors to complement or contrast with the vision glass.
Provides heat and impact resistance when made from tempered or laminated glass.
Essential component of curtain wall and structurally glazed building designs.

Disadvantages of Spandrel Glass

Highly transparent glass cannot be perfectly matched with spandrel glass .
Ceramic enamel frit used as an opacifier can reduce the flexural strength of heat-treated glass by up to 50%.
Thermal stress issues are increased when using low-e coatings or dark colors in the spandrel cavity, potentially leading to glass breakage.
Shadow box spandrel designs are vulnerable to condensation, debris buildup, and volatile organic compound (VOC) staining.

Low-E Glass vs Spandrel Glass

Comparing Energy Efficiency

Low-E glass is a standout here because of its heat-reflective properties – it’s engineered to keep heat out during the summer and in during the winter, which can lead to significant savings on heating and cooling bills.

Spandrel glass, on the other hand, is not typically used for energy efficiency – its primary role is aesthetic, concealing areas that don’t need to be seen, and it doesn’t have the same thermal performance as Low-E glass.

Analyzing Cost

Low-E glass tends to be more expensive upfront due to its specialized coating. However, the investment can pay off in the long run with the energy savings it provides. Spandrel glass, while potentially less expensive initially, doesn’t offer the same energy benefits. If you’re looking for long-term savings, Low-E glass might be better.

Installation Concerns

Low-E glass requires careful handling to protect the energy-saving coating during installation. For example, when installing low-E glass, workers must be cautious not to touch the coated surface with bare hands, as oils and dirt can compromise its effectiveness.This can mean a more delicate and sometimes more costly process.

Spandrel glass is a bit more forgiving during installation since its main purpose is to cover and not to insulate or let light pass through.

Maintenance Considerations

Once installed, both types of glass have different maintenance needs. Low-E glass should be cleaned with care to avoid scratching or damaging the coating. Spandrel glass, being less delicate, is generally easier to maintain since it’s robust and doesn’t require special cleaners or methods.

Aesthetics Showdown

Low-E glass is clear and provides a crisp view, which can enhance the building’s aesthetics while still being energy efficient.

Spandrel glass comes in various colors and finishes, allowing for design flexibility and the ability to blend in with the building’s exterior.

Ideal Uses for Each Glass Type

So, when should you use each type of glass? Here’s a quick rundown:

When to Use Low-E Glass

Areas with large windows or glass doors where energy efficiency is desired.
Spaces where UV protection is important to prevent fading of materials.
Regions with extreme temperatures, either hot or cold, to help manage interior climate control.

When to Use Spandrel Glass

Between floors of a multi-story building to conceal floor slabs and structural elements.
On parts of the facade where mechanical systems or other building components need to be hidden.
Where uniform exterior aesthetics are crucial to the building’s design.

Comparison	Low-E Glass	Spandrel Glass
Energy Efficiency	– Highly energy efficient, with coatings that reflect heat while allowing visible light transmission – Helps reduce heating and cooling costs	– Primarily used to conceal building elements, so does not provide the same energy efficiency benefits as low-e glass
Cost Considerations	– Carries a small cost premium over standard glass, but energy savings can offset this over time	– May be slightly less expensive than low-e glass, as the opacifying coatings are simpler to apply
Installation and Maintenance	– Requires careful handling during installation to avoid damaging the delicate coatings – Minimal maintenance once installed	– Generally easier to install, as the opaque coatings are less vulnerable to damage – Minimal maintenance once installed
Aesthetic and Practical Considerations	– Allows for high visible light transmission while controlling heat and UV, making it well-suited for vision glass areas	– Designed to be opaque, concealing building elements and providing a uniform appearance to the facade – Can be customized in a variety of colors to complement the vision glass
When to Use	– Areas with high temperature fluctuations – Homes where UV protection is important – Regions with a mix of hot and cold climates – Homes that get a lot of sunlight – Cold climates	– Curtain wall and structurally glazed building designs – Hiding building components like HVAC, wiring, and plumbing – Complementing vision glass – Commercial construction projects

Table comparing the characteristics of low-E glass and spandrel glass.

Making the Right Choice with Panda Windows & Doors

At Panda Windows & Doors, we understand that choosing the right glass for your project can be a complex decision.

That’s why we offer expert guidance to help you weigh the benefits of low-E and spandrel glass. We’re here to make sure that your selection meets your energy efficiency and aesthetic needs – and aligns with your budget and maintenance capabilities.

The Panda Process

1. Design: We assist you in choosing the perfect custom luxury glass doors and windows from our selection of over 80 options. Tailor every detail, including glass types like low-E or spandrel glass, to meet your specific needs. Review and approve your sales order to ensure all specifications are correct before we commence manufacturing.

2. Manufacturing: Our project manager verifies all necessary components and procures any unique materials required. CNC machines precisely cut and mill extrusions, which are then thoroughly cleaned and powder-coated for a durable finish.

3. Quality Control: Each product undergoes rigorous inspection and testing on our test wall to ensure smooth functionality and high quality. We provide you with photos and videos of your products before packaging to confirm everything meets your expectations.

4. Packaging & Shipping: We wrap each product in protective materials and place them in custom-built crates to ensure safe transit. Whether shipping domestically or internationally, we guarantee your order arrives intact.

5. Delivery & Warranty: Upon delivery, inspect your order and register the product to activate the limited warranty. Apply a high-quality finish to any wood surfaces within 7 days to prevent damage. Ensure proper installation and protection during construction.

6. Care & Maintenance: Follow our care and maintenance guide to keep your products in top condition. Regular cleaning and upkeep will ensure they remain functional and beautiful for a lifetime.

Frequently Asked Questions (FAQ)

What Defines Low-E Glass?

Low-E glass is defined by its microscopically thin, transparent coatings that reflect heat. These coatings are made of metallic oxides that allow the glass to provide insulation against heat transfer, which makes it highly energy efficient. The ‘E’ in Low-E stands for ’emissivity,’ which refers to the ability of the glass to radiate thermal energy.

The most important feature of Low-E glass is its ability to maintain a comfortable indoor temperature by reflecting interior heat inside during colder months and by reflecting exterior heat away during warmer months. This balance makes Low-E glass a top choice for those looking to reduce their energy consumption and costs.

Where Is Spandrel Glass Typically Used?

Spandrel glass is normally used in parts of a building that require the concealment of structural components, such as the spaces between floors, behind wall cladding, or around columns. Its primary function is to provide an aesthetically pleasing cover for areas that are not meant to be visible, such as ceiling spaces, insulation, or ventilation systems.

This type of glass is often seen in commercial buildings, where it contributes to the uniform and modern appearance of the facade. It’s also used in areas where light transmission is not necessary or desired – for a sleek and continuous look to the exterior of a structure.

Since spandrel glass is available in a variety of colors and finishes, it can complement or contrast with the building’s design. This versatility allows for creative freedom in design, making it a popular choice for modern architecture.

Can Low-E Glass Save Energy in Any Climate?

Yes, low-E glass is designed to be versatile and effective in a wide range of climates. In hot climates, it reflects the sun’s heat away from the building, reducing the need for air conditioning – in cold climates, it keeps the warmth inside, lowering heating costs. This adaptability makes Low-E glass a smart choice for energy savings, no matter where you’re located.

What Are the Cost Differences Between Low-E and Spandrel Glass?

The initial cost of Low-E glass is typically higher than that of Spandrel glass due to its specialized coatings.

However, the long-term energy savings provided by Low-E glass can offset the upfront cost over time. Spandrel glass, being less technologically advanced, is usually less expensive initially but doesn’t offer energy-saving benefits.