Within the finished Singular Strategic Project about Bioclimatic Architecture and Solar Cooling (SSP-ARFRISOL), five buildings were built or restored - Research and Development Buildings - using bioclimatic architectural designs and solar based HVAC and DHW systems. This article is about the overall operation of the HVAC and DHW system installed in the building number 70 of CIEMAT in Madrid. It consists of a solar collector field, linked with absorption machines to obtain cold water, "Solar Cooling", as well as the support of conventional means. The system and its operation are described, and then an eleven-month period of operation, under real use conditions, is analyzed from an energetic point of view. The methodology described in this article allows detecting energy sinks and abnormal operations, where the critical points are, and eases to make corrections. We also include an example of optimization using this methodology applied to this system and, after the changes were made in the configuration and the operation, a further energy analysis for the next four months. (C) 2014 Elsevier B.V. All rights reserved.