I. Introduction
Heat dynamics of building temperature system can be traditionally derived from the principles of heat conduction, convection, radiation and simplified to a heat transfer model which requires the knowledge of physical characteristics of materials used in the building. Typical variables in the dynamics are room (or indoor) temperatures, outdoor temperature, solar radiation, heating or cooling devices in the room [1], [2], [3]. Simplified thermal dynamics in a room can be described by a first-order differential equation which is equivalent to a thermal RC (resistance/capacitance) network. Knowing dynamical models of the system allows us to analyze the system characteristics, predict room temperatures at a certain time, and also provide a plant model for engineers to control operations for the heating or cooling devices. For these reasons, estimation of model parameters of the building energy system has become a topic of interest in many studies [4].