The solar spectrum consists of three types of radiations: ultraviolet beams, the visible light and the infrared ones, the latter is invisible but it warms the solid or gaseous matter, creating the heat sensation that so much concerns the organism. The effect of the pollution of the gases, the greenhouse effect called, provokes a climatic warming that is translated in an increase of the everage temperature, an increase that raises half a degree Celsius every 10 years.
All these aspects have been contemplated in a study, where there is detailed that in a terrace, the heat that is perceived is the generated one for the direct beams of the Sun joined that of the elements reflectantes of the environment.

Under a awnings, the calorific contribution diminishes thanks to the low degree of energetic transmission of the canvases (30 % as maximum, according to colors) and the reduction of the temperature of the surfaces protected by the canvas.
It is possible to say that the solar factor calculated according to norm EN 410, indicates the total quantity of solar radiation transmitted by a canvas. In addition, it allows to evaluate the decrease of temperature perceived by the persons placed under the canvas in summer conditions (temperature of the air 30 ° C, without wind), the lower it is the solar, more limited factor it will be the heat contributed by the solar flow.