Parametric analysis and multi-objective optimization of a solar heating system for various building envelopes

The objective of the present work is to investigate energetically and financially a solar assisted heating system for various building envelopes in the climate conditions of Greece. The examined solar heating system includes flat plate collectors, storage tank, boiler and heating devices. The analysis is conducted for the locations of Athens and Thessaloniki which are the most populated cities in Greece. The total analysis is conducted with the TEE-KENAK software which is the official software of Greece for energy audit studies. Different insulation thicknesses are examined (from 0 cm up to 8 cm) and three different glazing scenarios are also investigated. The collecting area is studies from 0 m2 up to 30 m2 for all the building scenarios. The results are evaluated energetically and financially. The optimum design scenarios are determined using the net present cost criterion, as well as through a multi-objective optimization/evaluation procedure. Finally, it is found that the optimum design for Athens is the use of 6 cm insulation layer, double glazing (G2 quality) and 30 m2 solar collectors, while the optimum scenario for Thessaloniki is the use of 8 cm insulation layer, coated glazing (G3 quality) and 30 m2 solar collectors. The results of this work can be applied for the proper design of the Greek buildings regarding the new buildings and the retrofitting cases.