Guide

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For a long time, sun shading have not only been considered as an element for improving comfort at work and leisure. Changing climatic conditions and rising energy prices make shading an important component of any building, not only reducing costs but also contributing to environmental protection.
Modern energy-efficient buildings are designed to maximise the use of the sun's rays as a natural source of heat, making it all the more necessary to offset the impact of the sun during the hot months of the year.  By using solar shading, the operation of air-conditioning units can be significantly reduced, thereby lowering electricity consumption. Users can take full advantage of the benefits of solar shading systems with control automation that reacts to changes in the weather.
The energy saved translates into the amount of toxic substances that would be produced in energy production and carbon dioxide emissions. Special programmes, which simulate the energy balance of a building, calculate accurate data assessing the effectiveness of solar shading.

The use of a light intensity sensor (also known as a sun sensor), connected to the sunshade drive control, not only increases the comfort of the system, but also contributes to increased energy savings.
How does the sun sensor work?
If the light intensity exceeds a threshold value for 2 minutes, the opening/extension movement is triggered. When the light intensity is below the threshold value for 15 minutes, a closing/retracting movement is triggered. Time delays and hysteresis have been introduced so that the system does not react to short-term changes in weather conditions, so that the motor does not overheat (taking into account its continuous running time) and is always ready for emergency retraction.
What are the advantages of a system with solar automation?
By automatically reducing the penetration of thermal radiation, thermal comfort is increased. This is particularly effective when using external shading. The internal temperature in a room with solar shading is 5°-10° lower than in a room without such shading (if the sun's rays fall on the window). If air-conditioning is used, the energy that would have been used to cool the interior is saved, thus reducing costs. By automatically uncovering the shades at low light levels, the use of artificial light can be reduced. This can result in considerable savings in lighting systems that switch on and off automatically to provide constant illumination of workplaces. By supplementing the sun sensor with a temperature sensor, it is possible to additionally use the function of reheating the room if the indoor temperature is lower than set. Winter gardens are an example of such an application. The light sensor can also be used in some systems to detect dusk and roll down the sun shading to protect privacy.    

Interiors that are full of sunlight require effective sun protection. When deciding to purchase them, it is important to remember that external screens are much more effective. They retain heat energy outside, preventing a significant increase in temperature inside the room, while at the same time improving the aesthetics of the building.
In the case of interior shading, infrared waves are converted into heat energy at the sheathing and raise the temperature inside.
Well-chosen solar control systems are a worthwhile investment for years; they not only increase the comfort of the home, but also help to save energy by reducing the need for air conditioners.

In order to estimate the payback time of the sun shading purchase, we assume that the room is equipped with an air-conditioning and heating system and that a temperature range has been established that must be maintained inside the room (by means of an automatic controller). The payback of the purchase costs is directly determined by the energy saved, which would have been spent on cooling (we block the heat input) and heating. The cost savings can be calculated using building energy efficiency simulation programmes.
The rate of return depends on several factors:
- the size of the window in relation to the volume of the room,
- the type of glazing, - location in relation to the world directions,
- geographical coordinates,
- the type of solar protection,
- air exchange rate coefficient with the surroundings,
- the type of automatic control adopted,
- the cost of purchasing the shade.
Taking into account the above factors, the payback time for the purchase of solar protection systems is between 5 and 15 years.
A study* was carried out in our climate zone, comparing the energy consumption of windows without an external solar control system, but with glazing fitted with a coating that blocks the transfer of thermal energy, with windows with an external solar control system controlled by a sun sensor (uncoated glazing). They have shown that by using glazing with a coating that effectively permanently blocks heat energy from the sun, we are depriving ourselves of the possibility of reheating the room with solar energy in autumn-winter and winter-spring. On the other hand, by using a dynamic solar shading system, we achieve significant energy savings (for cooling and heating the building). The advantage of dynamic shading over fixed shading comes from the ability to block energy and deliver it when it is needed. The use of a solar panel makes the system fully autonomous.  Solar shading offers not only cost savings, but also comfort for users and contributes to environmental protection by reducing energy consumption.  *Based on "AWNINGS AND SOLAR-PROTECTIVE GLAZING FOR EFFICIENT ENERGY USE IN COLD CLIMATES".