|Meaning of Symbols|
The film that we assess offers the best value for money - highest performance at the lowest cost, taking into account heat (TSER) and insulating performance (U-value), high Visible Light Transmission (VLT) and low Visible Light Reflection.
The difference in price between films is often greater than the difference in performance.
|Highest heat (TSER) performance|
|Second highest heat (TSER) performance|
|Third highest heat (TSER) performance|
Best performance against a specific criteria - for example, highest VLT, lowest VLR, lowest U-value, lowest price.
|Glossary of Terms|
|Windows Energy Rating Scheme - performance data has been independently tested and verified as correct|
|2. VLT %||Visible Light Transmission - % of visible light that passes through the film. Usually more is better|
|3. VLR %||Visible Light Reflected - % of visible light that is reflected by the film. Clear glass has a VLR of 8%. The higher the VLR the more shiny (mirrored) the film appears. A personal preference but usually less is better|
|4. UV Blocked %||UltraViolet Light Blocked - % of UV light blocked by the film. UV causes sun damage and fading, so more blocked the better|
|5. U-Value||A measure of the flow of heat through a window (glass and frame): the lower the U-value, the better the insulating ability of the window - will keep the interior warmer in winter and cooler in summer|
|6. SHGC||Solar Heat Gain Coefficient - a measure of the amount of heat that can be gained through your windows at times of direct solar contact. The SHGC is important as during summer the SHGC can add large amounts of unwanted heat to your house. Equally in winter the SHGC can be utilised to provide cost and pollution free heat from the sun. The Solar heat gain is measure as a coefficient and indicates the amount of direct solar heat that will penetrate your house. |
The SHGC is mainly affected by the glazing type. Products like tinted glass and applied films can help to reduce the SHGC. It is important that when selecting windows and doors the orientation, location and house design are all considered to achieve the best outcomes. In cooler climates it is often advantageous to have a higher SHGC and in hotter climates a lower SHGC is better. To comply with energy reports, the SHGC must be within 10% of the set value,
|7. TSER %||Total Solar Energy Rejected - % of solar energy (Visible Light + UV Light + InfraRed Light) blocked by the film. All three forms of solar energy will convert to heat energy. Higher % blocked is better but should compare films with similar VLT. Blocking more visible light will improve TSER but make a room feel darker.|
| ||These films are very light in appearance and provide some heat, fading and glare protection|