A State-Space Identification of Building Temperature System

This paper considers an estimation of state-space system matrices of a building temperature system. The building model has two rooms equipped with air-conditioning (AC) system where they contain heat interactions with walking path and the outdoor. Only one-dimensional heat transfer and internal energy change have been concerned while neglecting the effects caused by humidity and air leakage. Cooling energy from the AC system is expressed via the coefficient of performance (COP) and is a nonlinear function of room temperatures. We propose an approximate linear model with an assumption that the COP is a constant obtained by the air-conditioner specifications or it can be estimated. Temperature data and air-conditioners electrical input data can be collected by the Chulalongkorn University Building Energy Management System (CUBEMS) and therefore allow us to estimate the model parameters using the least-squares approach. Our results show that the model with a structure on the input matrix that agrees with physically-based dynamical equations is recommended and including the solar radiation as an input is not necessary.