INVESTIGATION OF THE DETERMINATION OF THE COST-OPTIMAL THICKNESS OF THE THERMAL INSULATION LAYER OF THE WALLS OF A MODERNIZED PUBLIC BUILDING

Abstract

The aim of the work is to conduct an investigation of the determination of the cost-optimal thickness of the thermal insulation layer of the walls of a modernized public building. The tasks of the research are as follows: to create a research model by using a typical detail of a modernized Lithuanian public building; to perform calculations of the heat transfer coefficient of the walls of a public building; to determine the optimal thickness of the wall thermal insulation layer when using the energy of district heating networks; to analyze which energy efficiency class of a building and what thermal insulation thickness is rational for a modernized public building. Research methods: the analysis of technical and scientific literature, and empirical modeling. In this article, the author carried out a research on the typical wall detail of a public building, based on the principles of energy and economic efficiency. The empirical research has shown that the cost-optimal thermal insulation layer corresponds to an energy efficiency class ‘A+‘ building and the optimal insulation thickness is from 180 to 240 mm (EPS70N). Taking into account the Lithuanian construction technical regulation No. STR 2.01.02:2016, the energy efficiency classes ‘C‘ (120 mm) and ‘A++‘ (270 mm) are not the cost-optimal solutions.