INTERNATIONAL JOURNAL of RENEWABLE ENERGY RESEARCH G. Aboina et al., Vol.10, No.3, September, 2020 Analysis of the Influences of Internal Heat Loads on a Solar Heating System Equipped with a Heat Pump G. Aboina * , M. Abdou Tankari * , A.Mahamat Tahir ** , G.Lefebvre * * CERTES Laboratory, University of Paris Est Créteil, 61, Avenue du Général De Gaulle, 94010, Créteil Cedex ** Team Higher National Institute of Sahara and Sahel of Iriba (Chad) (gerard.aboina@u-pec.fr and mahamadou.abdou-tankari@u-pec.fr) Received: 29.01.2020 Accepted:xx.xx.xxxx Abstract- The work presented in this paper is the study of a solar heating system of student’s classroom occupied in the day. This system includes solar thermal collectors, a water storage tank, a heat pump and low temperature hot water radiators. Several heating scenarios have been defined according to the internal heat supply. The objective is to analyze the impacts of each type of internal heat transfer on the performance of system components and thermal comfort. Ambient air temperature regulation is ensured by an on-off regulator that controls the operation of the heat pump and the circulating water pump in the radiators. The system model has been implemented in the Matlab/Simulink environment for simulation. Keywords: Heating, Building, Regulation, Thermal confort, Matlab/Simulink. 1. Introduction Men spend more than 90% of their time in an artificial environment (transport vehicles, workplaces or homes) [1]. The habitat whose function is to shelter its occupants from bad weather, in order to cope with climatic adversity in winter and ensure a pleasant and comfortable environment by heating, is a source of significant energy consumption [2]. In France, the building sector consumes annually, according to the Scientific and Technical Center for Building (CSTB) in June 2006, 47% of energy, half of which is due to heating, against 28% for industry and agriculture and 25% for transportation. This important winter consumption of energy by buildings is a quest for a state of satisfaction and well-being towards our thermal environment, called thermal comfort.Thermal comfort is a concept whose appreciation is largely subjective. For this purpose, for the same thermal environment, a first person can feel comfort while another can feel discomfort. This subjectivity is justified paradoxically by objective foundations. The appreciation of comfort is linked to the metabolism of the person and the exchanges made with the thermal environment. These exchanges depend on the person's constitution, state of health and physical activity [3]. Because of subjectivity of the thermal comfort concept, the American Society of Heating and Air Conditioning Engineer (ASHRAE) specifies the body standards of comfort as a whole in terms of operating temperature. This temperature takes into account air temperature, thermal radiation and the air velocity up to 0.15 to 0.2m/s. Thus, for a relative humidity of 50%, ASHRAE standard defines comfort temperatures in the range of 23 to 26°C in summer, and 20 to 23.5°C in winter [7]. These temperature ranges are slightly displaced at a moisture level of 50% or below [3].The search for comfort in winter induces a significant increase in energy consumption of various origins with all its consequences: very high bills, peaks in consumption, greenhouse gas emissions. [2] That is why, today, it is an obligation for everyone to integrate in their daily lives, the use of renewable energies, including solar thermal in the production system of hot sanitary water and especially the residential heating. In general in domestic or residential heating, the thermal inputs from the solar flows play a key role in the energy consumption of the building. In addition to these external thermal inputs, internal inputs such as lighting and human metabolism are no longer negligible. Unfortunately, they are very little considered in most studies dealing with heating. For this purpose, as part of our study where a solar heating system incorporating a heat pump, several heating scenarios will be studied. The different study scenarios are defined according to lighting and human presence with the hypothesis a sunny sky. These are : - S1: Heating with lighting on and presence of people; - S2: Heating with lighting on and absence of people; - S3: Heating with lighting off and absence of people; - S4: Heating with lighting off and presence of people. The purpose of our work is to analyze the influences of internal heat apply on heating system performance and thermal comfort. The system in its conventional