Shading is an effective way to save energy in buildings. Good shading design can enrich the indoor light distribution while saving energy, as well as the building shape and facade effect. 

    Nowadays, the indoor and outdoor environments of buildings are controlled intelligently or in an automated manner to achieve the safety and energy saving of the building. When the intelligentization of HVAC and lighting systems is gradually accepted by people, the many advantages of intelligent shading systems are be ignored.

    1. The concept and characteristics of intelligent sunshade louver

    Different from old-fashioned sun shading systems, smart sun shading systems are usually composed of sun shading louvers (curtains), motors and control systems. The control system software is an integral part of the intelligent shading control system. It is used in conjunction with the control system hardware. According to the changes in the surrounding natural conditions, through the system circuit, the curtain angle is automatically adjusted or the overall lifting is performed to complete the intelligent control function of the shading shutters. It not only blocks radiant heat, reduces direct sunlight, avoids glare, but also makes full use of natural light to save energy.

According to its own characteristics, the intelligent sunshade system can be divided into manual electric control and induction intelligent control. Manual electric control can artificially adjust the angle of the sunshade system according to the angle and intensity of the sunlight in a day. Inductive intelligent control is to automatically adjust the sunshade direction, angle, position, and sunshade area of the sunshade through the sensor's induction of the sun's height, position, and direction of the sun's irradiation, and the sun's intensity, so as to achieve the purpose of sunshading. This kind of sun shading system has a particularly good effect on the sun shading used in the roof daylighting system.

    2. Intelligent system of intelligent sunshade louver

    The intelligent shading system mainly relies on its intelligent control system to achieve the purpose of energy saving.

    The most widely used intelligent shading control system is based on the technology of the control network, which can realize the following functions: The system calculates the elevation and azimuth angles of the sun in different seasons, dates, different periods and different directions based on local meteorological data and sunshine analysis results . Then the intelligent controller controls the turning angle of the blinds in different directions according to the set time period. The multi-directional sunlight sensor installed on the roof detects whether it is sunny or cloudy. On cloudy days, the system controls the shutters to open horizontally; on sunny days, it is executed in the sunlight automatic tracking mode. At the same time, the occlusion model is established according to the shape of the building and the surrounding buildings, and the daily shadow changes at the reference point are calculated and stored in the motor controller. , And then run automatically according to the results.

The software of the intelligent sunshade control system includes two parts, the computer monitoring software and the intelligent node control software, and the main functional modules.

    3. The design of smart sunshade louver in smart building

    3.1 Principles of automatic sunlight tracking and leaf turning

According to the latitude and longitude of the location of the building, the software can be used to calculate the elevation and azimuth angles of sunlight in different seasons and at different times, and the results can be directly stored in the motor controller. The motor controller will automatically calculate the corresponding sunlight angle, and automatically flip the blades to an appropriate angle with the set angle as the step length to block the direct sunlight.

    3.2 Set up sun tracking

    According to the shape and orientation of the building, a number of reference points are set on the facade of the building, and the reference points are analyzed for four seasons.

     Software is used to calculate the sunlight elevation and azimuth angles of each reference point in different seasons and different moments according to the orientation and height of the building.

    The calculation results are stored in the motor controller and run automatically.

Turn the angle of the blades at any time to prevent sunlight from directly entering the room, and at the same time, open the angle as much as possible to maintain a good visual effect and let natural light reflect to the indoor ceiling.

    3.3 Calculate the effect of building shadow on shading

    During the operation of the sun, the building itself casts shadows on neighboring buildings, and the surrounding tall buildings may also block the building. The window where the shadow is projected does not actually need to be shaded, otherwise the room will be darkened, so the blades need to be level or stowed.

    Build a model based on the floor plan and elevation of the building.

    Using the elevation angle and azimuth angle of each reference point just calculated, the shadow change of each day and year is calculated according to the shadow of the surrounding buildings and the shape and orientation of the building.

    Once these data are calculated, they are recorded in the louver controller.

    At different times, the louver controller automatically knows which reference points are in the shadow according to the stored calculation results, and turn the blades to a horizontal position to allow more light to enter the room.

    Intelligent shading system is an indispensable part of building intelligent system. As a shading system that can improve the indoor environment of buildings and improve the living quality of buildings, its intelligentization will be the intelligent building system and the most potential branch, and it will also contribute to energy saving. Make a huge contribution. And with the continuous advancement of technology and the popularization of building intelligence, building shading will have a more complete intelligent control system, and the use of smart shading systems in intelligent buildings will become more and more prominent.