The basic tasks of each window include letting in the right amount of natural light. The lighting of the interior is largely influenced by the technical parameters of the glass. The light transmitting factor speaks of how much visible solar radiation enters through it.
Role of light transmitting factor
Among the most important parameters describing the properties of glazing is the light transmitting coefficient Lt. This indicator indicates how much visible solar radiation, falling on the glass at an angle close to 90°, enters the room. It is calculated as the ratio of light passing through the glass to the amount of visible solar radiation falling on it. Therefore, the light transmitting factor is expressed as a percentage. The high value of the parameter indicates that the use of a given glass is associated with a well-lit interior. As a result, less electricity is needed to illuminate the room. In accordance with PN-EN 410,the light transmitting factor is determined as ?V.
What does light transmittance depend on?
One of the factors influencing the amount of light entering the interior is the number of glass panes in the glass package. The more glazing in the contribution, the harder it is to achieve a high Lt factor value. In addition, the degree of light transmittance depends on the composition of the raw materials used in the production of glass. The thickness of the individual panes forming the shaft insert is also of great importance. Moreover, the value of the Lt factor is influenced by the presence of low-carbon coatings, which are used to limit the escape of heat from the room to the outside. They reduce the amount of visible light entering the interior. However, this does not mean that the use of low-emission glass is associated with poorly lit housing. Modern low-emission coatings, such as climaguard? Premium 2,have a beneficial effect on the thermal insulation of the window,while providing the right amount of light in the room. The value of the light transmittance coefficient may be altered by using suitable glazing to control sunlight.
