ABSTRACT
The energy consumption for heating could be reduced minimizing the heat losses of the building and increasing the efficiency of the heating systems. During the operation of central heating systems disturbances may occur, which have a negative influence both on the obtained thermal comfort and the real energy consumption. The scope of this research was to analyze the effects of different disturbances on the internal temperature and energy consumption taking into account the most used supply/return temperature of the heating fluid before and after thermal rehabilitation of the building envelope. Using the energy balance equations the internal temperature variation was obtained. Writing the equation of energy consumption for a heating season, using the degree-day curve, a relation between energy consumption deviation and internal temperature gradient was found.
