Heat sources — technology, economy and environment

Abstract

Heat sources for heat pumps in buildings as well as in industry are discussed. Furthermore, some environmental aspects concerning choice of heat source are highlighted. Only systems for heat pumping are included, i.e. air-conditioning types which can also partly work as heat pumps are excluded. Recent heat pump installations in Sweden are mainly in small systems. Ambient air, exhaust air, soil and rock are the most common heat source types. Data on COP, investment costs, working fluids, present Swedish market etc. for these types of heat sources are given. Data on industrial heat pump installations in some countries and distribution of these according to heat pump type and industry sector as well as heat source temperatures are reported. Process integration aspects when choosing heat source size and temperature are also discussed as well as the relation between these parameters and the choice of heat pump type. Finally, the influence on the economy of the heat source temperature is presented. The cost-effectiveness of heat pumps for reducing CO 2 emissions compared with other heating technologies is discussed. The main results are: (1) heat pumps can in many cases in the future contribute to a reduction of CO 2; (2) there is a rather big difference, for larger systems a major difference, between the water-based and the ambient air-based heat pumps in terms of efficient reduction of greenhouse gas emissions.