Understanding solar protection
How does solar protection work ?
Outdoor applications
| Indoor applications
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Any solar radiation partly passes through the fabric, is absorbed or is reflected by the fabric. The sum of the three equals 100. Ts + Rs + As = 100 % of the solar energy received by a wall.
Solar transmittance (Ts) : This factor measures the proportion of solar radiation that passes through the fabric alone.
A low percentage indicates a good reduction of solar energy by the fabric alone.
Solar reflection (Rs) : This factor measures the proportion of the solar radiation reflected by the fabric alone.
A high percentage indicates good reflection of solar energy by the fabric alone.
Solar absorption (As) : This factor measures the proportion of the solar radiation absorbed by the fabric alone.
A low percentage indicates low absorption of the solar energy by the fabric.
Visual transmittance (Tv or TL Light transmission) : invariably called visible transmittance (Tv) or light transmission (TL), visual transmittance (Tv) indicates the percentage of light radiation that is visible to the human eye. With a wavelength of between 380 to 780 nm (nanometres), it determines the part of the visible spectrum passing through the fabric.
Various parameters enable a good match between the solar protection sought and a suitable fabric to be defined :
- The building's orientation
- Geographic location
- Seasons
All these elements cause the solar radiation's direct impact on the window to vary.
