Identification of the Real Thermal Characteristics of Existing Buildings

Abstract

The identification of the real thermal characteristic of an existing building implies mainly the assessment of the invariants specific to that structure, namely the equivalent thermal conductivity of the materials used for the opaque external envelope of the dwelling space. The paper focuses on the problem of identifying the thermal characteristic of the opaque external envelope of the apartment buildings with central heating system and implicitly with heating units in the dwelling and commune. The method used is of the inverse modelling type, based on the building global balance and on the thermal response of the heating system to random climatic conditions. The problem implies two phases as follows: - the preliminary phase, consisting in the integration of the heat balance differential equation of the dwelling spaces; - the final phase, based on the thermal response characteristic of the heating system in real operation conditions.

Keywords

• global heat transfer coefficient
• thermal conductivity
• mass flow-rate
• exponent specific to the heating element
• ventilation rate