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Platform on sun and daylight control, shutters, patio covers and closures
The steady march of climate change means that summer thermal insulation is becoming increasingly central to new construction and renovation. Reducing heat input from sunlight is not just a comfort issue for users: it is more than ever a necessary building block for more climate-resilient buildings.
Through an automation of shading, the facade reacts quickly to external conditions and thus becomes climate-active. Such a "climate-active façade" keeps out much of the solar energy in summer. Due to the low energy permeability, overheating of interior spaces is avoided - and therefore often energy-intensive technical cooling. In contrast, upwardly moved shading systems enable the targeted entry of radiant energy in winter and thus support heating. In winter nights, energy losses through the window can be reduced by closing the shading up to 37% (due to the additional thermal resistance of a shutter in combination with a conventional window (Uw=2.7W/(m²K)). Daylighting can also be improved by automation, especially in the case of louvered products, leading to a reduction in artificial lighting requirements.
For Warema, the system concept is at the forefront of building envelope optimization. The components essential for energy input, glazing and shading, are included in a total energy value: the total transmission (gtot). By perfectly coordinating both components, heat radiation can be efficiently reduced. The following applies especially to shading: Only an intelligent control makes optimal use of the technical possibilities within the framework of a climate-active facade.
The gtot value is composed of the transmitted radiation and the secondary heat input from the absorbed radiation trapped between shading and window. Decisive factors in shading are the reflection of heat-intensive radiation with a large wavelength and the lowest possible transmission value combined with precise control of the required daylight. The good news is that the user can sit back and relax in terms of control. An automatic performs the control significantly better, and especially proactively. Standard components for this are a weather station and a control unit with an intelligent control algorithm that, among other things, takes into account the seasonal position of the sun, adjusts the slat position if necessary and regulates the louver heights depending on the weather.
The reputable engineering firm Prof. Dr. Hauser (IBH) was commissioned through the RTG (Representative Office for Transparent Building Envelopes) to conduct several studies on the effectiveness of shading devices. In the current IBH 4 study, calculations on a model of a predefined test room with a floor area of about 45 m² and a south-facing window area of about 36% of the room's floor area show the major advantages of external shading and intelligent control: With conventional operation of external shading, the number of hours with indoor temperatures above 26°C can be reduced from 2,781 hours (without shading) to 512 hours. With early activation via automation, such as with a climate-active facade, the number of hours can be reduced even further to 212 hours. This corresponds to a value of just under 10 percent - compared to the situation without shading. With additional night cooling through ventilation, the number of hours with indoor temperatures above 26°C can even be reduced to 39 hours, i.e. a value below 2 percent.
Of course, the best energy value is always achieved with closed blinds. However, the rooms behind them can then only be used to a very limited extent due to the lack of sufficient daylight without artificial lighting. But: Unused rooms are not necessarily a special case, but very often standard. The precise recording of these times using presence detectors, registering Sundays and holidays, working hours and vacation periods and including these in the control of the climate-active façade is another, often untapped energy saving potential.
The perfect balance between amount of daylight and degree of shading is one of the central factors for effective heat insulation in summer. Outdoor blinds offer the greatest advantage and flexibility here. By perfectly adjusting the slat angle to the current elevation angle of the sun, it can be achieved that no direct sun rays enter the room - at the same time maximum, diffuse daylight input. By preventing direct solar radiation, there is no strong energy input, the controlled diffuse daylight input enables additional energy savings in artificial lighting.
Just the fact that already about 40 percent of the incoming heat radiation can be reflected by a slat sunshade is already good news. In terms of planning, however, we must move away from the idea of "one fits all." Each building should be considered individually. This applies to both renovations and new construction, which is why Warema actively supports architects and specialized planners on this complex issue. The future of efficient thermal insulation lies in the intelligent use and perfect interaction of all installation systems in the building. Perfect shading systems combined with smart control solutions are therefore more than just a recommendation for Warema. These opportunities to optimize the building envelope must be exploited: proactively.
