Energy and Buildings 48 (2012) 146–154 Contents lists available at SciVerse ScienceDirect Energy and Buildings j our na l ho me p age: www.elsevier.com/locate/enbuild Assessing the energy consumption for heating and cooling in hospitals Velimir ˇ Congradac a,∗ , Bogdan Prebiraˇ cevi ´ c b , Nikola Jorgovanovi ´ c a , Darko Staniˇ si´ c a a Faculty of Technical Sciences, Trg D. Obradovi´ ca 6, 2100 Novi Sad, Serbia b ION Solutions, Laze Kosti´ ca 7 21000 Novi Sad, Serbia a r t i c l e i n f o Article history: Received 10 December 2011 Received in revised form 27 December 2011 Accepted 14 January 2012 Keywords: Energy demands Mathematical tool Optimization a b s t r a c t This work is a part of a larger project initiated under the patronage of Europe’s Information Society, within ICT PSP – ICT Policy Support Programme 1 in order to increase energy efficiency in hospitals, using a variety of currently available technologies. A prerequisite for the determination of savings is the accurate calculation of energy consumption and then the application of different methods of intelligent control for the energy savings, which should be combined with a system of expert advices in order to gain the highest efficiency. This study concentrates on the first part of the problem – the creation of a mathematical tool for the exact calculation of room/building energy demands. © 2012 Elsevier B.V. All rights reserved. 1. Introduction In recent decades the increased attention is paid to the optimiza- tion of energy consumption wherever possible, and large buildings and business centers, which include tens of thousands of square meters of area and a number of floors, are one of the priorities in this scope. Therefore, different software packages such as EnergyPlus [1] are developed to enable high-precision modeling of buildings and energy balance calculations, thus determining the amount of energy needed for heating and cooling, both for existing and objects that are in the designing phase. However, given that these programs provide only consumption but not the power-saving features and suggestions, it was necessary to find a new approach to the whole concept, an approach that would enable (besides consumption) the calculation of potential savings using different intelligent energy controlling methods. In addition, this approach should be simple, since it would be primarily intended for ordinary engineers and technical staff responsible for the maintenance of the building (in this case in particular hospitals) and not for research purposes. This is not the first tool which uses that approach [2], but it is among the first that integrates the assessment of consumption, savings methods and ease of use. Many researches are dedicated to the energy demand prob- lem and building modeling. Ayres [3] as early as 1977 presented both the approximate and more precise computer methods for ∗ Corresponding author. Tel.: +381 631010120. E-mail address: velimir@uns.ac.rs (V. ˇ Congradac). 1 Call identifier CIP-ICT-PSP-2008-2, Project full title “Intelligent Energy Efficiency Control in Hospitals”, Project acronym “HosPilot”; www.hospilot.eu. predicting building energy consumption. Balcomb [4] introduced diurnal heat capacity which allowed beneficial use of stored energy balance during the half-day-cycle periods in the building, while degree-day concept (as described by Eto [5]) at the same time eases the calculations and increases the accuracy of the estimated energy requirements. To include all the remaining important factors, heat- ing and cooling loads must be considered – gain through glazed surfaces [6], internal heat gain, infiltration, etc. After development of EnergyPlus, many studies used this tool for obtaining [7] or verification of energy consumption data, even with control strategies recommendation when comparison with measured data gives satisfactory results [8], but none of them pro- vides a general solution that would unite the energy demands and potential savings within them. Another very important thing worth mentioning is that hospi- tals have long been out of sight in terms of this issue, despite its size and opportunities for savings (Fig. 1) [9]. The main reason is the viewpoint that patients should be provided with maximum com- fort and all the necessary conditions; however, applying modern technologies and management strategies can keep the same level of comfort with significant savings in consumption. At the same time, many of the rooms are standard offices and clinics, in which energy control strategies can be applied as in any other institution. 2. The purpose and objectives definition The two main problems that arise in connection with the assign- ments are: defining a list of methods that can achieve cost savings and integration of a mathematical tool which should calculate savings. 0378-7788/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.enbuild.2012.01.022