1 Monitoring the Heat Pumps Prof. Nyers M. Jozsef D. Sc. , Nyers J. Lehel M. Sc. Polytechnic Engineering College of Subotica, TERA TERM doo. 24000 Subotica, Vojvodina, Yugoslavia Tel: +381 63 8477799, E-mail: jnyers@vts.su.ac.yu Springer's book series . Towards Intelligent Engineering and Information Technology, (Studies in Computational Intelligence), Vol. 243, p.573-581, ( print IBSN 978-3-642-03736-8) Springer Berlin, Heidenberg. 2009. Abstract. The aim of this paper is to stress the importance and necessity of monitoring heat pumps. The descrip- tion and the analysis of individual activities in all the components of a heat pump are given from the point of view of monitoring problems. The components of the monitoring system are also analyzed, with respect to their operation and installation. The schemes for installation and connecting the components of the monitoring system, depending on the strategy of the control system are given as well. 1 Introduction A heat pump is a cooling device, operating on the principle of left-side cycle. It is used for transporting heat energy from lower to higher temperature levels by means of mechanic work or heat energy. In engineering practice, heat pumps with a compressor, that is those which operate by consuming mechanic work, have primarily been used. Devices with a compressor have a higher efficiency factor than absorption systems. With implemented systems that have a compressor the total efficiency factor reaches the value of 1: 3, 5. 2 Technical Description Heating or cooling systems based on heat pump exchange heat energy with renewable sources, which are usually the outdoor air and groundwater. The consumer of thermal energy is either a building or a technological process. The system is comprised of three subsystems: the source, the transporting unit and the consumer of heat energy. A continual supply and removal of heat energy must be ensured for the continuous operation of the system. A flow of working mediums must exist in all three subsystems. The analyzed water - water systems are made up of two water and one cooling cycle. The flow of working me- diums is enabled by the pump in water circular flow and by the compressor in the cooling cycle. Working mediums are water and refrigerant, Freon. 3 Monitoring the Water - Water Heat Pumps 3. 1 Introduction The monitoring system is used for inspection of heat pump components by observing the relevant state parame- ters. Parameters show the state of the observed system components. The monitoring system is at the highest hierarchical level, above the control system. In case the operation of the sys- tem is disturbed, the monitoring system through the a control unit switches off the supply of energy into the system, thus preventing damage. The lack of proper monitoring and intervention might lead to serious damage, and even explosion of the con- denser, fracture of the compressor and freezing of the evaporator.