International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 03 Issue: 05 | May-2016 www.irjet.net p-ISSN: 2395-0072 © 2016, IRJET | Impact Factor value: 4.45 | ISO 9001:2008 Certified Journal | Page 29 Mathematical Modeling of buildings towards the design strategy of the Green buildings with MATLAB B.Vikram Anand 1 , Asit Kumar Mohanty 2 , Soumya Ranjan Mishra 3 , Nara Narayan Das 4 Satya Gopal Mishra 5 Subham Sial 6 1 Assistnat Professor, Department of Electrical Engineering, GIET, Gunupur, Orissa, INDIA 3,4,5,6 Final Year UG student, Dept. of Electrical Engineering, GIET, Gunupur, Orissa, INDIA ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - Maintaining of the indoor climate conditions so that they keep compatible with the occupants comfort is a key issue for control of heating, ventilation along with air conditioning systems (HVAC systems). Computer modelling offer a virtual environment similar to real climatic conditions indoors and outdoors. It aims basically to devise solutions for control of indoor climatic conditions. This process requires understanding of these environments from physical and mathematical perspective, so that physical processes of these environments can be represented using relationships and equations which can reflect the influence of different environmental parameters. Here different physical models associated in the construction of building are modelled and a new control strategy is developed to limit the effect of temperature rise using MATLAB/SIMULINK and the output results are shown which results in better performance. Key Words: HVAC system, mathematical modeling, temperature, control. 1. INTRODUCTION It is must to have a better knowledge about the heat, air and moisture balance of the whole building and how the indoor environment is affected due to it. And it in turn impacts the thermal comfort of the occupants which invariably reduces pollution and energy consumption. There is no such tool or computer application in existence which covers these issues. Hence, integrated mathematical models which cover every aspects of building design are required. Modeling is defined as obtaining the mathematical equations which shows the dynamic response of the physical processes. It is basically derived from the known laws. The physical system, once its modeling is completed [1]; it can be simulated by a particular software tool. It just takes few seconds to simulate the process, as compared to the real system as it takes hours. It helps in saving a great deal of money and we can correct the errors before the real system is implemented. For predicting the energy being consumed and what are the indoor climate parameters, some popular methods can be used[2][3]. The results which are obtained from these methods are used to design the buildings, which meets every aspect of the energy consumption and indoor climate. The principles of energy simulation are to determine the energy flow across the building. Energy flow is found out in terms of heat loss through the building envelopes with also the ventilation system and infiltration. It is quite evident that the actual indoor temperature is the representation of complex interaction between losses and gains. The variables used vary continuously as outdoor temperature, solar heat gain and internal heat gain, vary with time [4]. All the parameters which directly or indirectly affect the energy balance must be included in the model. This in term says that every wall, windows, ventilation system and all the components sub-model must be designed. With so many sub-models being designed come so many factors, which further increase the complexity of the whole model. And with many factors, a detailed result will be obtained. But we may have problems in running it. Accuracy and complexity must be balanced in such way that, we get higher accuracy with less complexity. The mathematical model is again run in various simulation processes. After the initial implementation of the model, validation of the model is important as to check whether the results obtained are near to real parameters. There is a big advantage of simulation, as we can vary the parameters and can further improve the design of the building [5]. There is only one software that has advanced capabilities for simulation of indoor thermal process, and it is MATLAB.SIMULINK is a software package which is basically used for modeling, simulating and analyzing dynamical systems. Using ordinary differential equations, the indoor environment modeling can be implemented in SIMULINK. Here in this work a closed room is considered, where an external wall and windows separate it from the outdoors, internal partitions divide it from the adjoining rooms, and from above by a ceiling and a floor slab at below and it is shown below in figure 1.