Simulation of heat transfer at the junction of the attic floor to the building envelope

Abstract

Numerous studies and thermal imaging inspection of multi-storey residential buildings indicate characteristic places with increased heat loss. In houses built in accordance with modern domestic regulatory requirements for the thermal resistance of enclosing structures, the actual thermal resistance of walls and windows coincides with the standard. However, nodes of elements of external enclosing structures with increased values of heat loss were found. Insulation of the junction points allows increasing the thermal resistance of the external enclosing structures. In order to increase the energy efficiency of a building, the design of the insulation of the junction of the ceiling in the technical attic has been proposed, which is protected by a patent for a useful model. The linear heat transfer coefficients of the junction point of the ceiling in the attic are analyzed. It was revealed that such information was not indicated in the regulatory documents. Reducing heat loss is achieved by arranging additional layers of insulation in the form of aerogel slabs at the junction of the ceiling to the external enclosing structures. The analysis of the energy efficiency of the proposed design of the junction unit of the attic floor as a "cold bridge" was carried out according to the results of mathematical modeling in the DAMWERK software package. Based on the simulation results, the temperature distribution in the junction of the ceiling in the technical attic was established. The linear heat transfer coefficient of the recommended junction point of the ceiling in the technical attic has been determined, the value of which should be taken into account when developing the Energy Efficiency section. The results obtained confirm the feasibility of introducing the proposed structural design of the floor abutment unit in the technical attic, which will improve the energy efficiency of the building's thermal insulation envelope.