Heat Rejection Explained: Understanding the Numbers

Window tint specifications can be confusing. Let's break down what each number means and why it matters.

Key Metrics Explained

VLT (Visible Light Transmission)

What it measures: The percentage of visible light that passes through the tint.

• 50% VLT = Light tint, 50% of visible light gets through
• 35% VLT = Medium tint, 35% of visible light gets through
• 20% VLT = Dark tint, 20% of visible light gets through
• 5% VLT = Limo tint, only 5% of visible light gets through

Lower VLT = Darker appearance

IRR (Infrared Rejection)

What it measures: How much infrared heat is blocked by the tint.

Infrared radiation makes up about 53% of the sun's energy and is the primary cause of heat buildup in your car.

| Tint Type | IRR Range | |-----------|-----------| | Dyed | 5-15% | | Carbon | 40-50% | | Ceramic | 80-90% | | Nano-Ceramic | 95-99% |

Higher IRR = Cooler cabin

TSER (Total Solar Energy Rejected)

What it measures: The total amount of solar energy blocked, including UV, visible light, and infrared.

TSER gives you the complete picture of a film's heat rejection capability.

• Basic dyed: 25-35% TSER
• Carbon: 40-55% TSER
• Ceramic: 55-70% TSER
• Nano-ceramic: 65-80% TSER

UV Rejection

What it measures: The percentage of ultraviolet rays blocked.

Most quality films block 99%+ of UV rays, regardless of type. UV protection is important for:

• Preventing skin damage
• Protecting interior from fading
• Reducing eye strain

The Math in Real Life

Let's see how these numbers translate to real-world temperature differences:

Scenario: 100°F outside, car parked in direct sun for 1 hour

| Tint Type | Interior Temp | Temp Reduction | |-----------|--------------|----------------| | No tint | 150°F | — | | Dyed (35% VLT) | 140°F | 10°F | | Carbon (35% VLT) | 125°F | 25°F | | Ceramic (35% VLT) | 110°F | 40°F | | Nano-Ceramic (35% VLT) | 100°F | 50°F |

What Numbers Should You Look For?

For maximum heat rejection:

• IRR: 90%+
• TSER: 60%+
• Look for ceramic or nano-ceramic

For balanced performance:

• IRR: 70-80%
• TSER: 50-60%
• Ceramic is ideal

For budget-friendly protection:

• IRR: 40-50%
• TSER: 40-50%
• Carbon offers best value

The Bottom Line

Don't just look at VLT (darkness) when choosing tint. The real performance is in IRR and TSER numbers. A 35% VLT ceramic tint will keep you significantly cooler than a 5% VLT dyed tint, despite appearing lighter.

At SolaroTint, we provide full specifications for every film we install. Ask our technicians about the numbers that matter most for your needs.