OPENING Introductory address by Mr. G. M. V. ~ AARIENNE, Minister of Economic Affairs of 3 the Netherlands Opening address by Dr. A. STRUB, Corrmission of the European Communi ties, 6 Brussels KEYNOTE SPEECHES Building physics: indispensability or a vogue discipline? A. C. VERHOEVEN, Delft University of Technology, Department Civil Engineering, Delft 13 The problem of the transfer of the results of research and innovatioos into the sector of energy conservation G. ELIAS, Faculty of Engineering, University of Palermo 16 The low energy hospital H. CDJIX>lAN, Department of Health arrl Social Security, london 21 Le diagnostic: un prealable a la rehabilitation thermique des batiments existants J. C. BONCORPS, Agence Fran~aise pour la Maitrise de l'Energie, Paris 24 Developnent of nodern heating technology F. STEIMLE, Institut fur angewandte Thermodynamik und Klimatechnik, Universitat Essen 30 SESSICN I - HEAT PUMP SYSTEMS A -R&D PROJECTS Personal impression of the sessioo chairman 43 Influence of lubricating oil 00 heat pump performance - Data capture, anal ysis and control aspects J. T. McMULLAN, D. W. HUGlES, Energy Study Group, 46 New University of Ulster, Coleraine -vii- A single screw high performance heat pump B. ZIMMERN, E. KALIMANN, QnIiJale S. A. , Puteaux 55 Investigation of commercial domestic heat pump performances H. MARrIN-NEUVILLE, J. P. PA'lUREAU, M. REYBILLET, Division Energetique, Societe BERTIN & Cie, Plaisir 62 Optimized operation of a frozen air heat exchanger by using a micro-computer R.