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The ground-coupled heat pump (GCHP) system used to provide space heating for an office room is a renewable technology with a high performance. The experimental measurements are used to test the performance of a GCHP system integrated with the radiator or radiant floor heating system for an office room. A comparative analysis of the main performance parameters (energy efficiency and CO 2 emissions) is performed for the two heating systems. Additionally, two numerical simulation models of useful thermal energy and the system coefficient of performance (COP sys ) in heating mode are developed using the TRNSYS (Transient Systems Simulation) software. Finally, the simulations obtained using TRNSYS software are analysed and compared to the experimental data, resulting in good agreement and thus the simulation models are validated. [ABSTRACT FROM AUTHOR]

Abstract: This paper deals with the method of decreasing the size of heat exchanger surfaces by increasing the heat transfer coefficients and the importance of heat transfer enhancement for vaporization. We report an experimental study on surfaces modified by passive methods applied to heat transfer surfaces mechanically processed, covered with sleeves made by metallic tissues or covered with metallic porous layers performed using welding procedures. Experiments are made to investigate the heat transfer coefficient on copper tubes with a 22mm external diameter using heat from inner source to outer vaporizing liquid. There are developed specific heat transfer correlations for each group of enhanced surfaces. The experimental data and new proposed correlations are compared with well known correlations. The results are in best agreement with the Cornwell–Houston correlation. [Copyright &y& Elsevier]

Highlights: [•] We provided a detailed review of different solar refrigeration technologies. [•] Theoretical basis and practical applications for cooling systems were presented. [•] Different working pairs were illustrated by their COPs and maximum temperatures. [•] It was explored solar hybrid cooling systems with heterogeneous composite pairs. [•] A comparison of various solar cooling systems and some use suggestions were given. [ABSTRACT FROM AUTHOR]