System efficiency increase in the planning and implementation phase

Already in the planning phase, system costs can be reduced and the prerequisites for maximum system efficiency can be created. The early involvement of all project participants (project developer, architect, site manager, building services planner, installer, operating company, etc.) is very important. The execution is also essential for the efficiency and quality of the solar system.

The dimensioning of the collector surface and the storage volume is an important planning criterion, as are the inclination and orientation. Optimal solar yields can be achieved with south orientation and with installation angles of about 30°.

The collector wiring is also relevant for optimal operation. Larger thermal solar systems should always be operated according to the low-flow principle. This means specific mass flows of about 5 to 20 kg/m2h. Characteristic features of a low-flow collector connection are a long thermal length and a small number of parallel strings. In combination with the low mass flow, this results in a large temperature swing within a collector flow with largely turbulent flow at the same time.

Determination of the hydraulic concept and control: “Low-flow” systems in connection with single-storage systems and heat distribution via two-pipe networks with home stations have established themselves as standard hydraulics in multi-storey residential buildings. The advantage of this concept is that the demands on the control of the entire system are extremely low.

Correct sensor positions: The collector sensor is mounted in the hottest collector at the collector outlet. Determination of the thermal insulation standard of pipes and energy storage: For efficient operation of the system, post-optimisation after commissioning is just as important as annual maintenance. (Salzburg Institute for Regional Planning & Housing 2006)