In Architecture we talk about solar protection to refer to the effect of the sun and the ability to regulate the temperature inside habitable premises. A glazed surface or an opaque surface needs to be protected from the sun without distinction. In each case the way in which the sun's heat will be transmitted to the interior of the premises will be significantly different.

Contenido

En el caso de superficies vidriadas o simplemente ventanas la radiación solar llegará a la superficie del exterior del vidrio y en condiciones generales medias el 86% continuará por el interior del local hasta encontrar una superficie opaca. Dependiendo de su color parte de absorberá y parte se reflejará. La parte absorbida calentará la masa del elemento y luego de calentada irradiará calor en el espectro infrarrojo, ya no visible al ojo humano.

Location of sun protection

Solar protection can be located either inside the premises to prevent the entry of solar radiation, in the space between two glasses in certain types of windows or outside.

For the same window facing midday and depending on the location of the sun protection, the temperature will not be the same within a room.

The table shows the changes in temperatures at various points for a constant outside temperature, depending on where the sun protection is located.

Types of sun protection

Sun protection is understood as any fixed or mobile device that totally or partially prevents the entry of solar radiation into a premises or room. We will have: blinds, roller blinds), shutters, parasol screens, awnings, balconies and overhangs, among others.

Each of these will have the capacity to partially stop the passage of the sun's rays and it is common to use a factor to determine this capacity.

The Solar Factor

The sun factor is small when the sun protection is opaque and light in color. If the sun protection is not opaque and partially allows the passage of solar radiation, the value of the solar factor F increases.

where:.

In the case of opaque surfaces, 100% of the radiation is received and depending on the color, part is absorbed and part is reflected. The absorbed part begins to heat the mass and the heat travels through it by conduction to then radiate the interior of the room in infrared and raise its temperature.

This, which can be beneficial in a cold climate or in the cold period of the year anywhere on earth, becomes harmful in hot climates or in the warm period. This is because it tends to overheat the interior of the premises above the hygrothermal comfort levels.

It is in these conditions that sun protection is necessary.