Owing to the double façades of the Courtyard and East buildings, it is possible to use the sunlight that shines through the large glass panels for passive heating – even just south of the Alps!
In the winter, the closed double façade works interiorly as an insulating grille, and externally as a single, suspended glass panel that buffers heat, making efficient use of sunlight with only minor heat loss. During summer, most available sunlight is absorbed by the blinds between the glass panels.
In addition, the surface temperature of the grille can be reduced by opening the flue and sliding elements located at the lower and upper positions, releasing warm air into the room like a fireplace. The active use of solar energy is based on an innovative heating and cooling system.
The amount of energy irradiated by the sun in Bolzano amounts to about 1200 kWh/m annually – assuming the receptor surface is optimally aligned – a third of which is absorbed during winter, 2/3 over the course of summer. Vacuum tube collectors are positioned over the flat roofs of the library, courtyard, central and east buildings to take advantage of this energy, with a total receptive surface of 472m².
The system provides for all water heating year-round, and during the transition periods of spring and autumn, for basic heating as well. In the summer, the system is driven to temperatures over 90°C, and together with the absorption cooler, provides the facility's air conditioning.
Energy use in excess of the solar collectors' thermal output is covered by a cogeneration unit, which is also the facility's primary heat source during winter. Two condensing boilers cover the peak energy requirements, as well as basic heating during low-usage periods (such as overnight). Dimensioning and regulation of the cogeneration unit is determined by the current consumption of the building; a network supply is not provided. The entire EURAC complex is actively ventilated, and the warmth in the winter (as well as cold during summer) is conserved using heat exchangers with a temperature efficiency of over 90%. In the office areas, the ventilation system brings in fresh air, while heating and cooling are optimized by low-temperature radiators and ceiling fans, both of which are thermostatically regulated, making it possible to adjust temperature controls for various areas of the facility according to need.