Introduction to the Special Issue on Energy Efficient Buildings

The current energy prices are at a historically high level. This, ombined with technological advances, has led to a surge in the nterest in energy savings in buildings. Buildings are traditionlly the domain of civil engineers, but from a modeling, control nd optimal operation point of view, there are strong similarities ith industrial processes, where use of control and other system ngineering methods have a long history. It is therefore strongly esirable to get a transfer of knowledge between the fields. Over the ast few years, there have been a number of dedicated sessions on uildings at the American Institute of Chemical Engineers Annual eeting and building control sessions at meeting organized by IFAC International Federation of Automatic Control) and at the Amercan Control Conference, among others. This growing interest and mportance of the subject motivated the Editorial Board to suggest special issue on “Modelling, control, optimization and monitorng of energy-efficient buildings”. A call for contribution was sent o selected groups who have been active in the area, and in addiion a general call was sent to the community, including in eletter Nov. 2012) and the CAST email list. Eventually, a total of seventeen apers were submitted. Subsequently, the papers went through the egular JPC review process. Thirteen papers were finally accepted nd are included in the special issue. In Thermal comfort control using a non-linear MPC strategy: A real ase of study in a bioclimatic building Castilla et. al., present a hierarhical thermal comfort control system with two layers. The upper ayer includes a non-linear model predictive controller that allows o obtain a high thermal comfort level by optimizing the use of an VAC system in order to reduce, as much as possible, the energy onsumption, with PID controllers at the lower level. The effectiveess of the proposed control system is discussed using suitable real esults obtained in a bioclimatic building. In the paper Inference of building occupancy signals using movng horizon estimation and fourier regularization, Zavala studies the roblem of estimating time-varying occupancy and ambient air ow signals using noisy carbon dioxide and flow sensor meaurements. A moving horizon estimation approach is utilized and emonstrated to be robust to high levels of noise. Computational xperiments with simulated and real data are used to demonstrate he effectiveness of the approach. Touretzky and Baldea in their contribution titled Nonlinear odel Reduction and Model Predictive Control of Residential Buildings ith Energy Recovery focus on understanding the dynamic behavor of buildings with an emphasis on energy management. First ingular perturbation arguments are used to provide a theoretical