Buildings with large glass areas represent one of the symbols of modern architecture. Glass surfaces allow making the most of the natural light, and thereby they fit naturally and harmonically into the surroundings.
Buildings with luminous glass facades do look attractive, but they also have a few disadvantages because solar energy and sun emission can cause problems in the interior of the building.
In normal conditions, glazed areas without protection transmit 88% of solar energy, where 80% penetrates directly into the interior of the building. Walls and household furniture absorb solar emission and transform that energy into long thermal waves that are retained in the interior. This exact phenomenon is the cause of the “greenhouse effect” that causes heat accumulation in rooms. In buildings with 50% or more of glazed areas, where windows are only single-glazed and exposed to sunlight without protection, and in case that windows are closed – interior room temperature reaches range from 10% to 15% higher than the temperature outside. For instance, when the outside temperature is 25°C, room temperature is 35°C or 40°C. If the outside temperature does not fall under the temperature in the interior of the building, the heat accumulated in rooms remains inside, and it cannot be reduced by transmitting the heat, nor by air circulation. Double glass windows have even lower heat transmission capacity.
