Performances of modern domestic hot-water stores Roman Spur a , Dusan Fiala b, * , Dusan Nevrala c , Doug Probert d a Department of Environmental and Building Services, Faculty of Civil Engineering, Czech Technical University in Prague, Czech Republic b Institute of Energy and Sustainable Development, De Montfort University, Leicester, UK c Enplan - heating technology company, Pod vodovodem, Prague, Czech Republic d School of Engineering, Cranfield University, Bedford, UK Available online 29 November 2005 Abstract Several designs of domestic hot-water (DHW) store, including those with immersed heat- exchangers (HXs), are commercially available. So there is a need for a method that accurately assesses their effectivenesses. In this study, the behaviours of a novel stratified, and two standard, stores were analyzed. The TRNSYS simulation software was enhanced to simulate the functioning of those stores. The resulting mathematical model was validated using measurements obtained from experiments, which required a realistic daily DHW draw-off for testing the DHW systems. Evalua- tion of a user-related effectivenesses (URE) for each of the three tanks tested showed that the inner configurations of: (i) the tank and (ii) the immersed HX can significantly affect the storeÕs perfor- mance. The stratified store was up to 32% more effective than the commonly employed commercially- available store. Ó 2005 Elsevier Ltd. All rights reserved. Keywords: DHW store; Immersed heat-exchanger; StoreÕs performance; Experimental analysis 1. Introduction Some of the DHW stores still on the market use the volumetric content of the tank as the store for the hot water. Other, more modern, designs employ water flowing through a HX, immersed in the hot water of the tank, for the supply of hot water to the householder because they appear to be more effective. The relative performances of different DHW 0306-2619/$ - see front matter Ó 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.apenergy.2005.10.001 * Corresponding author. Tel.: +44 0 116 257 7971; fax: +44 0 116 257 7981. E-mail address: dfiala@dmu.ac.uk (D. Fiala). Applied Energy 83 (2006) 893–910 www.elsevier.com/locate/apenergy APPLIED ENERGY First published in: EVA-STAR (Elektronisches Volltextarchiv – Scientific Articles Repository) http://digbib.ubka.uni-karlsruhe.de/volltexte/1000011412