The sizes of Flat Plate and Evacuated Tube Collectors with Heat Pipe area as a function of the share of solar system in the heat demandMałgorzata Olek, Piotr Olczak and Dominik KryziaE3S Web Conf., 10 (2016) 00139DOI: https://doi.org/10.1051/e3sconf/20161000139