# TSER, VLT, SHGC, IR Rejection — Window Film Spec Sheets Explained (Toronto 2026)

Quick answer. Every quality window film publishes a spec sheet with five to eight performance numbers. The five that matter most for Toronto residential decisions: VLT (visible light transmittance), TSER (total solar energy rejected), IR rejection (infrared specifically), UV rejection (fade protection), and glare reduction. SHGC and U-value also appear on architectural-grade spec sheets but require interpretation against the underlying glass. This post explains each number, what is realistic, and how to compare quotes from different brands without getting confused.

For the parent context see the pillar Window Tinting & Solar Film Toronto 2026 Complete Guide.

VLT — Visible Light Transmittance

The percentage of visible light that passes through the filmed glass. The number you see in product names: 3M Prestige PR 70 has VLT 68%; Llumar Vista VS 50 has VLT 50%; 3M Night Vision NV 15 has VLT 18%.

What VLT means visually:

VLT 70: nearly clear from inside, very subtle exterior tint. The room stays bright.
VLT 50: noticeably tinted from outside, slight reduction in interior brightness.
VLT 35: clearly tinted, ~25-35% interior brightness reduction.
VLT 15: dark and reflective, ~50-60% interior brightness reduction.

VLT is the most important consumer-visible number. Pick your VLT before your TSER — the room appearance is what you live with daily.

TSER — Total Solar Energy Rejected

The percentage of total solar energy (UV + visible + IR combined) the filmed glass system rejects. This is the headline heat-rejection number.

Realistic 2026 TSER ranges by film class on clear annealed glass:

Dyed: 25-35%
Carbon: 35-45%
Metallized solar: 60-75%
Ceramic mid-tier: 45-55%
Ceramic premium / 3M Prestige: 50-62%
3M Crystalline: 56-62%
Dual-reflective: 60-70%

TSER is calculated by ASHRAE-defined methodology and is comparable across manufacturers. When two films from different brands list 55% TSER, they are genuinely comparable.

IR Rejection — Infrared Specifically

The percentage of infrared (heat-carrying) energy specifically rejected. This is the sharper "will my room feel cooler" number than TSER.

Realistic IR rejection ranges:

Dyed: 10-20%
Carbon: 20-35%
Metallized: 70-85%
Ceramic: 88-95%
Nano-ceramic / Crystalline: 95-98%

IR rejection is what makes ceramic films feel cooler than dyed at the same TSER — most of the heat you feel comes from the IR portion of solar energy. A film at 95% IR rejection feels noticeably cooler than a film at 75% IR rejection, even if both list comparable TSER.

UV Rejection — Fade Protection

The percentage of UV-A and UV-B radiation rejected. This drives hardwood floor, fabric, art, and leather fade prevention.

Need professional home renovation?

Call RenoHouse at 289-212-2345 or get a free estimate today.

Get Free Estimate →

Virtually all professional films achieve 99-99.9% UV rejection. The 0.1% difference between 99% and 99.9% rarely matters in practice — both will drop fade rate to 5-15% of unfilmed glass. UV rejection is essentially a free benefit of any quality film, not a meaningful differentiator.

Glare Reduction

Percentage reduction in visible light glare. Mid-tier solar films cut glare 50-70%; reflective films 70-85%.

Glare reduction is correlated with VLT but not identical — a film can have moderate VLT and high glare reduction depending on the diffusion characteristics. For TVs, computer screens, and reading chairs glare reduction matters more than overall VLT.

SHGC — Solar Heat Gain Coefficient

A whole-glass-system rating: the fraction of incident solar radiation transmitted through the filmed window (lower is better for cooling). SHGC of 0.20 means 20% of incident solar energy enters the room; 80% is reflected or absorbed.

Pre-film SHGC on clear annealed double-pane IGU: 0.55-0.70.

Post-film SHGC with mid-tier ceramic: 0.30-0.42.

Post-film SHGC with premium nano-ceramic: 0.25-0.35.

Post-film SHGC with dual-reflective: 0.20-0.30.

SHGC is what HRS and ENERGY STAR window programs use. It is the architecturally-meaningful number for new-construction and replacement-window comparison. For aftermarket film, the manufacturer publishes the post-film SHGC against a reference glass — but your specific glass may be slightly different. SHGC is comparable across brands but requires the underlying glass spec for full accuracy.

U-Value (U-Factor)

The rate of conductive heat loss through the filmed glass system, in watts per square metre Kelvin. Lower is better for winter heat retention.

Pre-film U-value on clear double-pane IGU: 1.4-1.8 W/(m^2 K).

Post-film U-value with most solar films: 1.3-1.6 W/(m^2 K) — modest improvement (5-15%). With low-E retrofit films (a niche category): can drop to 0.9-1.2 W/(m^2 K).

U-value barely changes with most solar film. Solar film is a summer-cooling product, not a winter-heating product. If winter U-value is your priority, the answer is window replacement (under HRS rebate) or low-E retrofit film, not standard solar film.

Emissivity

The fraction of thermal radiation emitted by the film surface (lower is better for energy retention). Standard solar films have emissivity 0.85-0.90 (similar to clear glass). Low-E retrofit films can hit emissivity 0.10-0.30 (similar to factory low-E coatings).

Emissivity is a low-E retrofit conversation, not a standard solar film conversation. Most consumer-tier solar films do not change emissivity meaningfully.

Honest Spec-Sheet Reading Pattern

When comparing two films from different brands, look at:

1. VLT first — pick your interior brightness target.
2. TSER second — apples-to-apples across brands at the same VLT.
3. IR rejection third — sharpens "will my room feel cooler" compared to dyed/carbon at similar TSER.
4. UV rejection — confirm 99%+ (virtually always true).
5. Glare reduction — check if you have specific TV/laptop glare priorities.
6. SHGC — only matters if you are comparing film vs window replacement.
7. U-value — barely changes with film; ignore unless evaluating low-E retrofit film.

Common Spec-Sheet Tricks to Watch

TSER on tinted glass vs clear glass. Some manufacturers publish "TSER on bronze tinted glass" which inflates the number relative to clear annealed. Always confirm the reference glass. Room-side reflectance. Dual-reflective films publish low room-side reflectance (good — less interior mirror at night) and high exterior reflectance. Single-reflective metallized films may bury room-side reflectance because it is high (interior fishbowl effect at night). "Up to" performance. Watch for "rejects up to 80% of solar energy" without the specific TSER number. Read the actual spec sheet. SHGC alone without VLT. A film that lists SHGC 0.25 but does not list VLT may be very dark. SHGC alone is not enough.