Ordinary multilayer (CPVC/aluminum/CPVC) d16 (16 mm in diameter) pipe that is 22 meter long, connects the solar collector and the boiler. The pipe has 5 mm insulation. The multilayer pipe is situated inside a protective plastic 50x26mm pipe. Heat carrying and return multilayer pipes have been placed inside two separate protective plastic pipes. The pipes have been buried in the ground 1,8 meters deep. 3 additional temperature sensors have been connected for testing. In the diagram, temperature of the technical water which flows into the collector is demonstrated in blue color, temperature of the technical water which flows into the boiler’s heat exchange is portrayed in green, temperature of the technical water which flows out from the boiler is portrayed in violet. The said additional sensors have been measuring temperature for 16 days – from 10 May 2015 to 26 May 2015.
Here are the diagrams:
The diagram shows, that biggest losses in the underground pipes take place when the technical water carries heat from the collector to the boiler.