On a newly constructed building meant to become a school, an innovative and sustainable building automation system based on KNX standard was realized, which will save a significant amount of energy and guarantee a management optimization.
Invisible system
The building needs a heating-only system; as terminal for heat exchange among different environments, a ceiling radiant panel system has been selected. This false ceiling, made by suspended metallic panels integrates a series of hydraulic circuits filled with hot water. Reasons for this particular choice can be many: the indoor designer wanted to eliminate all visible radiators inside the rooms to gain more space, thus avoiding any interference with the students’ everyday life; the plant designer combined the low temperature of the water requested by the radiant ceiling with the heat pump, creating a system that distributes a uniform amount of heat in all environments’ angles.

Room temperature control with KNX
In line with the decision of making the terminals invisible, also the temperature control solution is not immediately visible in the rooms; to achieve this function, the ekinex pushbuttons EK-E12-TP, already foreseen for the manual control of blinds and lights, have been selected. These pushbuttons integrate an operational temperature sensor, which allows to individually control the rooms’ temperature without a visible thermostat students could touch at any time. In order for the temperature control to be optimized in big classrooms, a weighted average of the temperature values measured by two pushbuttons each one installed on a room’s opposite side. In the rooms meant for teachers, in the infirmary, in the headmaster’s office, in the library and in some common rooms, ekinex EK-E72-TP thermostats were installed; anyway, in the library and in the common rooms the thermostats are configured for a ±2°C variation only comparing to the set point configured during commissioning. The KNX control system is completed by ekinex EK-HE1-TP actuators for electrothermal drive control, installed on the intercept valves of each hydraulic circuit integrated inside the distribution manifold.
Special rooms: gym

Energy saving
Aiming at energy saving, ekinex EK-DF2-TP presence sensors have been installed on the classrooms’ ceiling; if nobody is present in the rooms, after some time sensors not only automatically switch off the light, but also change the operating mode of the heating system; this operation is possible thanks to the low inertia of the metallic heating false ceiling. In some rooms, EK-SM2-TP motion sensors have been used, which automatically switch on and off the lights; a proper off delay is configured and the switch on is only possible if the available natural light is not enough.
Other functions of the KNX building automation system
Il sistema di building automation KNX svolge numerose altre funzioni:
- Interface with DALI (Digital Addressable Lighting Interface) system for lighting control in the auditorium and library with dimmering and different management of direct and indirect components;
- Assistant personnel calling from the classrooms and remote bathroom alarms;
- Monitoring and control by central stations;
- Blinds angle control to protect glass surfaces on the south side;
- Protection blind and internal shades command in auditorium;
- Heating and sanitary water ricirculation time scheduling.



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