The building has 3 levels, each of them is 220 m2, of which actually 2 floors are used. Length of the building is 21 metre and faces to south-west direction. Other side of the building is built next to the warehouse. It’s made of burnt bricks (Wienerberger Porotherm 30 cm + heat insulation 15 cm). The calculated heat loss is 30kW. The used temperature step is 40/30˚C. The first floor level houses the commercial department (sales, purchasers, storekeepers). On the second floor level are placed the accounting, executive offices. The system serves two different purposes: heating and cooling. It is planned to use different kind of heat energy including fossil and renewable. On first floor a wood heating boiler is placed, which is heated with dropouts wood packaging (disposable pallets). A gas boiler, DHW storage tank and two puffer storage tanks are located on the second floor. On the flat roof, there are 3 rows of 6 solar panels in serial connection, facing directly south (installed with 45° slope). 80% of DHW requirement is produced by the solar plant. The working hours of the Comfort controller for DHW storage tank is 2578 hours (max temperature 72°C), for the puffer tanks is 2250 hours. (collector max temperature is 110,4°C.) The heating system consists of 3 heating zones (one for each floor), and many heating/cooling zones nearly equal to the number of rooms. Each one of the 3 heating zones are controlled by temperature regulator for mixing systems (RVA46 controller), while the ceiling heating/cooling zones are controlled with regulators, which can be turned to heating/cooling mode. The cooling system can reach 15°C-18°C cold water, in summer. The wood boiler directly charges the UBPU 1500 puffer storage tank.
Solar system strategy: Speaking about solar system controller, DHW storage tank has the priority on solar system: if its temperature is higher then the set value the controller turns the diverter valve to charge the second UBPT storage tank (1500 l puffer storage).
Gas boiler strategy: There is a boiler interface for climatic regulators (OCI 420) in the gas boiler’s control panel, to receive exact heating value needs. The gas boiler starts working if the storage tank heating value is not enough to fulfil the heating requirements which is calculated by a controller linked to temperature regulator for mixing systems (RVA 46) by DATA bus connection (MD-DB port).