IR Rejection

Have you ever noticed how certain rooms in your home become unbearably hot, even with the blinds drawn? The culprit might surprise you: it’s not just the visible sunlight streaming through your windows but also the invisible force of infrared radiation.

This often-overlooked solar energy component contributes to uncomfortable indoor temperatures and sky-high energy bills. But don’t sweat it! This blog post delves into infrared heat rejection, exploring how this innovative technology can help you reclaim a cool, comfortable, and energy-efficient home. Get ready to discover the science behind the heat, the benefits of keeping it at bay, and how you can harness the power of infrared rejection to your advantage.

Infrared heat rejection is a technology used in window films and coatings to reduce heat entering a space through windows. This technology specifically targets infrared radiation, which is a significant component of solar heat gain.

Infrared radiation is part of the electromagnetic spectrum emitted by the sun. It accounts for approximately 53% of the total heat we receive from the sun. The remaining heat comes from visible light (44%) and ultraviolet light (3%).

Infrared (IR) radiation, a form of electromagnetic energy invisible to the human eye, resides just beyond the spectrum of red light. This segment of the electromagnetic spectrum is characterised by wavelengths longer than visible light, extending from about 700 nanometers to 1 millimetre. Along with light and ultraviolet radiation, the sun’s predominant type of radiation, IR radiation plays a foundational role in various applications, most notably solar energy.

Did you know? Solar panels harness energy from the sun, converting sunlight into electricity. While most people associate solar power with visible light, IR radiation is a significant component of the solar spectrum that reaches Earth’s surface. Current technological advancements in photovoltaic cells seek to capitalise on IR radiation, with efforts to increase the efficiency of solar panels and extend energy generation beyond daylight hours.

Dissimilar to the ambient warmth from a household heater, the heat produced by IR radiation can alter the temperature of an indoor space. This thermal energy penetrates through windows, warming objects and surfaces directly. A substantial proportion of a home’s heat gain can be attributed to IR radiation, leading to innovative solutions in building materials, such as low-emissivity windows that reflect IR rays, thereby managing indoor temperature levels more effectively.

Infrared heat-rejecting films or coatings work by:

• Selective Filtering: These films contain nano-level particles that act as a filter, allowing most visible light to pass through while significantly reducing the amount of infrared radiation entering the space.
• Solar Absorption: Some films filter and absorb a portion of the infrared heat, which is then gradually released back outside.

Implementing infrared heat rejection technology offers several advantages:

1. Enhanced Comfort: These films create a more comfortable indoor environment by reducing heat gain.
2. Energy Efficiency: Less heat gain means reduced reliance on air conditioning, leading to lower energy consumption and costs.
3. UV Protection: Many infrared rejecting films also block harmful UV rays, protecting skin and preventing interior fading.
4. Glare Reduction: These films can help reduce glare, improving visibility and comfort.

When considering a good Infrared Rejection (IRR) rating for window tint, it’s important to understand that higher percentages generally indicate better heat rejection capabilities. However, looking at IRR in conjunction with other factors is crucial for a comprehensive assessment of a window tint’s performance. Here’s what you should consider:

High-quality ceramic window tints typically offer excellent IRR ratings:

• Top-tier ceramic window tints can provide up to 96% infrared heat rejection.
• Premium options offer up to 98% infrared heat rejection.

A good IRR for window tint is generally considered to be 80% or higher. However, the best performers on the market can reach up to 98%.

VLT measures the visible light that passes through a window or film. Key aspects of VLT include:

• VLT is a percentage representing the amount of visible light that can pass through the film or glass.
• A higher VLT percentage means more light is transmitted, resulting in a clearer or less tinted appearance.
• VLT is crucial in determining how dark a window tint will appear.
• Lower VLT percentages indicate darker tints that allow less light to pass through.

While IRR and VLT are separate measurements, they can both impact the overall performance of a window film:

• Traditionally, darker tints (lower VLT) were associated with better heat rejection. However, modern nano-ceramic films can provide high heat rejection even with higher VLT values.
• When selecting window films, it’s important to consider both IRR and VLT to balance heat rejection, visibility, and aesthetic preferences.

It’s better to consider the Total Solar Energy Rejection (TSER) value to represent a film’s heat rejection capabilities accurately. TSER considers heat from the entire solar spectrum, including infrared, visible light, and UV.

TSER provides a clearer picture of how much total heat a film can reject. For example, if a film has a 50% TSER, it means it rejects 50% of the sun’s total heat.

Whether you want to reduce reliance on air conditioning, protect your furnishings from fading, or simply enjoy a cooler, more comfortable home, infrared heat rejection technology provides a clear and compelling solution. And this technology isn’t limited to just your house! Think about your car on a scorching summer day. Infrared-rejecting window films can make a world of difference there, too, keeping the interior cooler and reducing the need to blast the AC.

Remember, when considering your options, look beyond just VLT and consider the TSER value for a comprehensive understanding of a film’s heat-blocking capabilities. Consult with the experts at EverClear Window Tinting to determine the best solution tailored to your specific needs.