Method for Studying the Influence of Thermal Inertia on the Room Temperature

Abstract

The efficiency of using thermal energy that is received from the central heating system to supply a building (a complex of interconnected rooms) is determined by the completeness of information available on the factors that affect the thermal regime. This article presents an approach that allows evaluating the significance for thermal management of such complex parameters as thermal inertia of a room and features of its use. The proposed methodology is based on the analysis of the dynamics of temperature changes in rooms, considering the standard characteristics that determine heat exchange, meteorological conditions, and the presence of people. The degree of the thermal inertia influence on a room is determined on the lag time, which is the time interval between a significant change in weather conditions or the supply of thermal energy and a change in the air temperature in the room. The initial data included the values of the temperature of the air and heating elements, that were obtained from the sensors located in a university building. The observation was conducted between 1 March and 19 April 2020 (measurement frequency — 10 minutes). The collected data consist of measurements gathered during room usage in different modes. Additionally, the presence of periods of complete shutdown of the heating system also affected the respective data. The module of the intelligent monitoring system for the thermal regime of the building was developed to perform data analysis. The module was implemented as a pipeline that sequentially performs the following operations: filtering and cleaning data; aggregation for specified periods; determination of the delay time. The results of the data analysis show the possibility of selecting groups of rooms that react to significant changes in external conditions and heating mode with a remarkable lag time. This confirms the importance of considering the thermal inertia for efficient heating control (intermittent operation). The results allow concluding that it is possible to build a classification model based on the thermal inertia parameter. These models will help in determining the most significant factors affecting the thermal regime of the room. In its turn, it allows producing recommendations for making decisions on heat supply management.