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Cooling circuits can be improved by using a desuperheater. A series connected desuperheater increases the efficiency of the circuit and allows the waste heat to be used, e.g., for DHW preparation. The study investigates the behavior of a parallel connected desuperheater for DHW preparation in an experimental cooling circuit. The basic parameters of the cooling circuit (efficiency, pressure, temperature and energy consumption) were evaluated when operating 1. with only a condenser and 2. with a condenser and a desuperheater connected in parallel. The results of the study show that a parallel connected condenser and desuperheater reduces the overall efficiency of the cooling circuit.

The contribution is an introduction to a new trend in the assessment of buildings as concerns their fire safety, and namely assessing the refrigerating system with refrigerants as such, forming an important part of the technological equipment of the edifice. Down to the present day both refrigerants and refrigerating systems used to be in the background of considerations, being handled as mere component parts of the ventilation systems, or even totally left out of consideration in fire safety statements relating to buildings. However, a certain improvement is seen to have set in, thanks to which refrigerants are claiming due attention. The reason for focusing upon their problems lies in the fact that refrigerants with high GWP index are being gradually replaced with low GWP index preparations ever since 2015, and namely due to the legitimate requirement of environmental protection. High GWP index refrigerants are even going to be prohibited after 2020. The shady side of this process is the considerable flammability of the newly introduced refrigerants. This is also why these problems arouse increased interest in the domain of the fire safety experts of the building trade on the one hand side, and among those specialized in refrigerating systems on the other hand side. This paper offers an outline of ways helping to solve the situation having set in. The aim of the paper is to point out the new situation in buildings where there are refrigerating systems with flammable refrigerants and the necessary measures resulting from the given situation, such as reducing the amount of refrigerant and the need to ventilate the space using cooling.

The passive solar test facilities have recently been created in many research centers all over the world to analyse dynamic outdoor phenomena on buildings and their components. The main objective of these research activities is primarily to evolve a methodology, improve test methods, validate numerical models and measure real thermodynamic properties of building components under outdoor climate conditions. An integration of advanced material solutions into buildings need to be investigated within specific conditions related specifically to outdoor test methods. A research project on Contemporary concepts of climatically active solar facades at the Brno University of Technology does have an ambition to create an experimental full-scale test cell for research of thermal aspects in progressive advances of future solar façade concepts exposed to the real climate conditions. This paper describes the design optimization phase preceding the test cell assembly. This phase includes the analysis of energy and thermal properties based on parametric study features. Computer simulations based on finite element and volume methods are involved in the optimization process. The proposed optimized test cell design is confronted with parametrization of typical thermal aspects to present final test cell demonstration.

Waste heat from cooling circuits can be a useful source of energy for other applications, such as domestic hot water heaters. Furthermore, by removing waste heat from the cooling circuit, its effectiveness can theoretically be enhanced. A number of previous studies have shown that waste heat can be effectively harvested by installing a desuperheater in the cooling circuit between the condenser and compressor. More recently, studies have concentrated on applying heat pumps in conjunction with desuperheaters in low energy houses. In this study, we describe an experimental laboratory-scale cooling circuit with a serially connected desuperheater for heating domestic hot water. We were able to verify that installation of a desuperheater between the compressor and condenser significantly increased the energy efficiency ratio of the experimental cooling circuit, thereby confirming the hypothesis that simultaneous use of waste heat increases the efficiency of cooling circuits.

Paper deals with the test procedure for evaluating performance parameters of the heat pump air water system. The objective of measurements was tuning errors and optimizes the work of the whole system. The main aim was to find the most acceptable evaporator with which the heat pump COP reached the best results. Choosing of the evaporator consisted of comparing the operating and performance characteristics of individual exchangers.

Oil is necessary for most of the heat pumps, cooling and freezing equipment, for proper operation of the compressor and other moving parts. Speed of the refrigerant vapor in the critical section, which is suction piping, is strongly dependent on the evaporating temperature, but also on the actual device performance. Well-designed piping is essential to the proper function of the cooling devices or heat pumps and affects the efficiency of the device. The aim of this paper is to describe problems of returning of oil in refrigerant devices and investigate the exact solution of design of refrigerant speed for carrying the lubricating oil in all segments of refrigerant pipes. Paper is based on facts obtained during developing of new refrigeration equipment. The resulting proposal of the device was numerically verified.