Pergamon Energy Convers. Mgmt Vol. 39, No. 7, pp. 609-622, 1998 © 1998ElsevierScienceLtd. All rights reserved Printed in Great Britain PII: S0196-8904(97)00050-2 0196-8904/9S$19.00+ 0.00 EFFECT OF CLIMATIC CONDITIONS ON THE DESIGN OPTIMIZATION OF HEAT PUMP SYSTEMS FOR SPACE HEATING AND COOLING OLYMPIA ZOGOU and ANASTASSIOS STAMATELOS* Mechanical Engineering Department, Aristotle University Thessaloniki, 540 06 Thessaioniki, Greece (Received 2 October 1996) Abstract--Domestic heating and cooling is responsible for a fair percentage of world energy consumption. Heat pumps offer the most energy efficient way to provide heating and cooling in many applications, as they can use renewable heat sources of the building's surroundings. A number of related heat pump technology versions exist that have led to significantly lower heating and cooling energy consumption in certain climatic conditions. In this paper, a comparative discussion is given of the effect of climatic conditions on applying ground source heat pump technologies. Specific examples are given for northern and southern parts of Europe. It is shown that the attainable building energy consumption reduction with ground source heat pump systems may be significantly higher in the warmer Mediterranean climatic conditions. To this end, advanced technology residential heat pump systems should be employed and their operation matched to the specific climatic conditions. It is concluded that climatic conditions significantly affect the performance of heat pump systems, which should lead to markedly different strategies for domestic heating and cooling, if an optimization is sought on sustainability grounds. © 1998 Elsevier Science Ltd. Heat pumps Coefficient of performance Solar energy systems and controls Climatic conditions Ground source heat pumps 1. INTRODUCTION Heating of buildings consumes about 25% of the primary energy used in the EU. The most widely used technology in this respect is oil or gas fired furnaces and boilers. Increased use of heat pumps could contribute to significant energy savings in this sector. About half of this primary energy in the EU is consumed in the form of oil, which is imported for the major part in Europe [1]. Compressor heat pumps could contribute to substitution of oil, as they provide heat by using electricity which can be produced from nuclear energy, coal or renewable energy. In addition, heat pumps could make a large contribution to pollution abatement, in particular in densely populated areas, depending on their efficiency superiority potential against conventional boilers. If the fuel used by conventional boilers were redirected to supply power of electric heat pumps, around 35% less fuel would be needed. The additional electric power requirement would result in somewhat increased pollution at the electricity plant, but this pollution could be more easily abated. Alternatively, the fuel savings could be raised to more than 50% with no additional electric power requirements, if electric heat pumps were driven by combined heat and power (cogeneration) systems. To exploit fully this potential, the electricity requirements of heat pump-based building HVAC systems should be minimized by exploitation of solar and ground heat where possible and controlled by means of advanced building energy management systems. Assessing the part of this potential related to the climatic conditions of the building's location is the aim of this paper. Steady-state performance of an electric compression heat pump at a given set of temperature conditions is indicated by the Coefficient Of Performance (COP). It is defined as the ratio of the *To whom all correspondence should be addressed. 609