Dynamic energy performance analysis: Case study for energy efficiency retrofits of hospital buildings Annamaria Buonomano a , Francesco Calise a, * , Gabriele Ferruzzi b , Adolfo Palombo a a DII, Univ. of Naples Federico II, P.le Tecchio 80, 80125 Naples, Italy b DI, Univ. of Naples Parthenope, Centro Direz. IS.C4, 80143 Naples, Italy article info Article history: Received 17 June 2014 Received in revised form 29 September 2014 Accepted 15 October 2014 Available online 7 November 2014 Keywords: Hospital buildings Energy refurbishment of buildings Energy audit Dynamic energy performance simulation abstract This paper investigates several actions for the energy refurbishment of some buildings of the University Hospital Federico II of Naples. The analysis focuses on a specific lot of 4 buildings, representative of the whole district hospital. For those structures, sustainable energy savings actions are investigated. They regard the installation of: i) roofs thermal insulation; ii) a substation climatic 3-way valve; iii) radiators thermostatic valves; iv) AHU (air handling unit) time-programmable regulation. This paper aims at presenting an investigation methodology, useful for designers and other stakeholders involved in hos- pital energy refurbishments, based on an integrated approach which combines dynamic energy per- formance simulations and experimental campaigns. In order to measure all the simulations' missing input parameters, a suitable experimental analysis, including measurements of temperature, humidity, flow rate and density of construction materials, is performed. A thermographic investigation is also performed for investigating the building envelope performance. This analysis showed that significant savings can be achieved especially by adopting radiators thermostatic valves and AHU regulations. Coherently, the installation of a 3-way valve in the substation does not determine significant additional savings when radiators thermostatic valves are already installed. For high-rise buildings, roofs insulation returns only marginal reductions of space heating and cooling demands. © 2014 Elsevier Ltd. All rights reserved. 1. Introduction Healthcare is provided in complex and energy-intensive facil- ities that range from critical care hospitals to medical office buildings. In general, they account for a remarkable fraction of the energy consumption in the utility buildings sector, due in large part to the very high energy intensity levels of hospitals and other inpatient care facilities. Particularly in hospitals, high energy con- sumptions are mostly due to their continuous usage patterns and operation which require substantially variable energy demands depending on the specialized services provided [1]. In addition, sophisticated heating, ventilation, and air conditioning systems are necessary to guarantee a careful control of hospitals internal climate. At the same time, high infiltrations and air changes are demanded by strict indoor air quality levels required by surgeries, intensive care units, white rooms, outpatient clinics, etc. [2]. Therefore, in order to guarantee and maintain satisfactory thermal comfort and indoor air quality levels, continuous demands of heating and cooling energy, as well as electricity (for artificial lighting and electrical equipment), yield remarkable energy con- sumptions, which are relatively higher in comparison with other types of buildings [3]. Hospital construction techniques also play an important role on the energy demands. In this regard, existing hospitals usually consist of large buildings, often known to be among the least energy efficient public buildings, as it is for most European countries [3]. As a result, hospital accounts for the highest energy consumption per unit floor area in the buildings sector and may offer great potentials for energy and cost savings through their refurbishment [4]. From this point of view, technical regulations and directives have been laid down aiming at providing guidelines and promoting measures for the reduction of the energy consumption of hospitals [5]. These measures must be adopted and applied to the hospitals design, construction, retrofit, operations and maintenance, also by integrating advanced energy efficiency technologies and renewable energy sources [6e8]. Nevertheless, the reduction of the energy consumptions must be achieved while preserving or enhancing healthcare delivery. From this point of view, it must be also noted that depending on the design conditions of each hospital function, the related technical system must be properly designed and adjusted in order to meet * Corresponding author. Tel.: þ39 0817682301; fax: þ39 0812390364. E-mail address: frcalise@unina.it (F. Calise). Contents lists available at ScienceDirect Energy journal homepage: www.elsevier.com/locate/energy http://dx.doi.org/10.1016/j.energy.2014.10.042 0360-5442/© 2014 Elsevier Ltd. All rights reserved. Energy 78 (2014) 555e572