Low-emissivity (Low-E) glass is a type of energy-efficient glass designed to minimize the amount of infrared and ultraviolet light that passes through it without compromising the amount of visible light that is transmitted. The result is a glass that helps regulate indoor temperatures, reduces energy costs, and protects interior furnishings from fading. This blog explores the different types of Low-E glass and their benefits, applications, and technical details.

What is Low-E Glass?

Low-E glass has a microscopically thin coating that is transparent and reflects heat. The coating can be applied to one or more surfaces of insulated glass units (IGUs) to enhance their energy efficiency. The coating works by reflecting long-wave infrared energy (or heat), thus keeping the heat inside in winter and outside in summer. It also blocks ultraviolet rays that can cause furnishings to fade.

Types of Low-E Glass

There are primarily two types of Low-E coatings used in glass manufacturing: Passive Low-E coatings and Solar Control Low-E coatings. Additionally, the coatings can be applied to different surfaces of the glass, known as Hard Coat (Pyrolytic) and Soft Coat (Sputtered).

1. Passive Low-E Coatings

Passive Low-E coatings are designed to maximize solar heat gain into a building to create a passive heating effect and reduce heating costs. This type of Low-E glass is ideal for colder climates where heating is the primary concern.

• Hard Coat (Pyrolytic) Low-E Glass: This type of Low-E glass has the coating applied during the glass manufacturing process when the glass is still hot. The coating is durable and can be used in single-pane applications. However, it is not as effective as soft coat Low-E glass in blocking heat.

• Soft Coat (Sputtered) Low-E Glass: Soft coat Low-E glass has the coating applied after the glass is made. This method results in a more efficient and higher-performing Low-E glass that is typically used in double or triple-pane insulated glass units. The coating is more susceptible to damage and must be protected within the IGU.

2. Solar Control Low-E Coatings

Solar Control Low-E coatings are designed to limit the amount of solar heat gain into a building, making them ideal for warmer climates where cooling costs are a concern. These coatings reflect a significant portion of the solar spectrum while allowing visible light to pass through.

• Hard Coat (Pyrolytic) Solar Control Low-E Glass: Similar to passive hard coat, this coating is applied during the manufacturing process and is durable. It is less efficient in blocking solar heat gain compared to soft coat options.

• Soft Coat (Sputtered) Solar Control Low-E Glass: This glass provides superior solar control performance and is used in double or triple-pane IGUs. The soft coat method results in a higher-performing glass that significantly reduces cooling costs in warmer climates.

Benefits of Low-E Glass

• Energy Efficiency: Low-E glass reduces heating and cooling costs by improving the insulation properties of windows.
• Comfort: It helps maintain a consistent indoor temperature, reducing drafts and cold spots near windows.
• UV Protection: Low-E glass blocks harmful UV rays, protecting interior furnishings from fading and damage.
• Reduced Condensation: The improved insulation reduces condensation on the interior surface of windows.
• Environmental Impact: By reducing energy consumption, Low-E glass helps lower the carbon footprint of buildings.

Applications of Low-E Glass

Low-E glass is versatile and can be used in various applications, including:

• Residential Windows: Enhances energy efficiency and comfort in homes.
• Commercial Buildings: Reduces energy costs and improves indoor climate control.
• Skylights: Provides natural light while minimizing heat gain or loss.
• Facades and Curtain Walls: Improves energy performance and comfort in large buildings.
• Automotive Windows: Enhances comfort and reduces energy consumption in vehicles.

How to Identify Low-E Glass and Ensure It's Performing Well

Identifying Low-E glass and ensuring its performance is essential for reaping its benefits. Here are some methods to help you:

1. Visual Inspection

Low-E coatings can sometimes give the glass a slightly tinted or reflective appearance. However, this is not always noticeable to the naked eye.

2. Use a Low-E Detector

A Low-E detector is a small, handheld device designed specifically to identify the presence of Low-E coatings on glass. Place the detector against the glass, and it will indicate whether a Low-E coating is present.

3. Check for Certification Labels

Reputable manufacturers often include labels or etchings on their glass products indicating the type of Low-E coating and compliance with energy efficiency standards. Look for these labels on the corners of the glass.

4. Perform a Heat Lamp Test

A heat lamp test can demonstrate the effectiveness of Low-E glass. Shine a heat lamp or an infrared lamp through the glass, and use a thermometer to measure the heat passing through. Low-E glass should significantly reduce the amount of heat transferred compared to regular glass.

5. Evaluate Energy Bills

Over time, properly installed Low-E glass should result in lower heating and cooling costs. Compare energy bills before and after installation to gauge the performance of the glass.

Technical Data of Low-E Glass

When evaluating Low-E glass, consider the following technical data:

• U-Value: Indicates the rate of heat transfer. Lower U-values represent better insulation.
• Solar Heat Gain Coefficient (SHGC): Measures how well the glass blocks heat from sunlight. Lower SHGC values indicate better solar control.
• Visible Light Transmittance (VLT): The percentage of visible light that passes through the glass. Higher VLT values mean more natural light.
• Emissivity: Indicates the efficiency of the Low-E coating. Lower emissivity values represent better performance in reflecting heat.

Conclusion

Low-E glass is a smart choice for enhancing energy efficiency, comfort, and protection in buildings. Understanding the different types of Low-E glass, their benefits, applications, and how to identify and ensure their performance can help you choose the right product for your needs. Whether you are looking to reduce heating costs in a cold climate or cooling costs in a warm climate, there is a Low-E glass solution that meets your requirements.

FG Glass - Your Partner in High-Quality Low-E Glass Solutions

At FG Glass, we offer a comprehensive range of Low-E glass products that meet the highest standards of performance and durability. Our solutions are designed to enhance energy efficiency, comfort, and protection in various applications. Discover how FG Glass can help you achieve your energy efficiency goals with our innovative Low-E glass products. For more information, visit fgglass.com