Kindergarten and apartments in Chur - Heating / Cooling / Ventilation

The city of Chur is paving the way for the energy transition with an innovative heat network concept in the retrofit of this Kindergarten & Apartments building. In the basement of the neighbour house there was a gas central heating which was replaced in 2014 by a pellet heating with a 1000L accumulator. This pellet heating from the neighbour supplies the Kindergarten & Apartments building with heat during the winter months. It also provides additional heating for the Domestic Hot Water (DHW), during periods when solar energy is insufficient. During the rest of the year, a Combined Heat and Power (CHP) system, composed of a combined PV and solar thermal system on the roof, provides the necessary energy for the heating and domestic hot water (DHW). 35m² of thermal collectors for hot water and heating support were installed on the roof of the Kindergarten & Apartments building. The final yield of reach approximately 21'000kWh per year. The yield covers the demand of about 19'000 kWh of the building by far, even a high surplus is balanced, but in the winter months the coverage is not sufficient. The surplus is transferred to the neighbour building at Calandastrasse 48. In return, the CO2-neutral pellet heating system from the neighbour building provides the missing heat for the Kindergarten & Apartments building during the winter months (Cf. Solution 13). The aim is to achieve an annual balance between exports and imports. BIPV and ST plants covers 95% of energy demand (NZEB). The project was awarded with the Swiss Solar Prize Diploma 2016 - Category B, Buildings: renovations.

The interventions for the heat production did not bring any particularly invasive interventions with the exception of the solar collectors on the roof The solar thermal system complies with many of the geometric and spatial and construction compatibility criteria required by current regulations for the integration of solar systems in historic buildings (grouping, coplanarity with the roof slope, respect for the eaves lines and roof edge, joint precision, etc.). The aesthetic, material and colour compatibility with the existing roof is not optimal, but the final result is good and well integrated with other new elements incorporated in the renovation of the building such as the dormers.