Thermal Dynamic Modeling and Simulation of a Heating System for a Multi-Zone Office Building Equipped with Demand Controlled Ventilation Using MATLAB/Simulink Ali Behravan, Roman Obermaisser Chair for Embedded Systems University of Siegen Siegen, Germany e-mail: Ali.behravan@uni-siegen.de, Roman.obermaisser@uni-siegen.de Amirbahador Nasari University of Siegen Siegen, Germany e-mail: Amirbahador.nasari@student.uni-siegen.de Abstract—Energy consumption of the office buildings demonstrates potential energy savings. One of the major parts of the energy consumption in these building is related to the heating, ventilation and air conditioning systems which keep thermal conditions in a comfort zone and indoor air quality in an acceptable range. Nowadays, building management systems are developed to reduce the energy consumption of these systems besides supplying occupants with comfort conditions. Furthermore, these complex systems can be faced by different operation faults. To diagnose and detect these faults, getting the knowledge about the system behavior through modeling is substantial. This paper introduces a scalable multi-zone office building model that was established in Matlab/Simulink using Simscape toolbox. The model contains the thermal dynamics of the building elements and the heating control system which is equipped with demand-controlled ventilation. The results show that the model can correctly describe and predict the dynamics of the system. The proposed approach is intended to be used for HVAC systems in building automation with a specific focus on faults diagnosis and detection. Keywords-simulation; modeling; Simulink; thermal dynamic; natural ventilation; carbon dioxide; demand control I. INTRODUCTION The building sector in the European Union (EU) consumes 40% of the total energy in the union [1, 2]. The energy consumption in the office building sector is almost 18% of the global energy consumption [3]. Energy consumption of the buildings is very dependent on the occupancy pattern, the outdoor environment, the structure specifications, and the materials. These statements demonstrate the importance of energy saving in the office building sector. One of the major parts of the energy consumption in these building relates to the heating, ventilation and air conditioning (HVAC) systems which keep thermal conditions in a comfort zone and indoor air quality in an acceptable range. Recent research trends emerged based on advanced control strategies in building energy management systems (BEMS) which indicate that there could be a potential energy saving up to 30% of total energy consumed in a building [4]. To optimize a complex building automation model, it is important to get the knowledge about the system behavior by analyzing the system model, because the model specifies what a system does. C. Lapusan et al. developed a multi-room building thermodynamic model based on 3R-2C network (3 resistors and 2 capacitors) using Simscape library from Matlab/Simulink [5]. A. Thavlov et al. presented a model for prediction of indoor air temperature and power consumption from electrical space heating in an office building, using stochastic differential equations [6]. This model was developed by SYSLAB. A. Thavlov showed that due to the high amount of natural ventilation in FlexHouse especially the nonlinear properties of wind, conditions should be integrated into the model, due to their influence on the indoor temperature. This paper considers another concept for the simulation, which also considers carbon dioxide (CO ଶ ) proliferation in office spaces due to human respiration that could cause some negative characteristics for occupants comfort e.g. feeling unwell, lack of concentration, and deterioration in efficiency. Natural ventilation is an effective method to improve indoor air quality (IAQ) and to dilute indoor CO ଶ concentration in offices. Therefore, this studied model includes the single- sided natural ventilation, a type of ventialtion that the air change is limited to the zone close to the opening. Demand- controlled ventilation (DCV) is a control strategy that modifies the amount of fresh air coming from outside environment delivered to a room by adjusting the position of damper actuator based on the CO ଶ sensor measurement. Most codes and standards specify some constant for required air change volume per person or per area for different places which can lead to over ventilation and increased energy consumption [7], while DCV profits the potential energy saving in heating systems by preventing excess outside low- temperature air from coming into the building spaces. Studies demonstrate that 15% to 25% of the HVAC system’s energy can be saved by setting the ventilation rates based on the maximum occupancy fresh air requirement [8]. According to this concept, this paper not only developed the thermal dynamic modeling and simulation of the heating system for a multi-zone office building in the aspects of accuracy and predictability by using novel governing equations, but also, to fill a sensible research gap in these kinds of simulations by considering the effects of CO ଶ 103 2017 International Conference on Circuits, System and Simulation 978-1-5386-0391-8/17/$31.00 ©2017 IEEE