This work describes a novel HVAC system consisting in a solar-assisted absorption ground coupled heat pump (GCHP). The aim of this work is to analyze some of the influence parameters on its energy efficiency. The installation has a complete instrumentation which provides instantaneous information on its actual behavior. The monitoring system consists mainly of temperature probes and flow-meters located in the main five water circuits of the installation: the three circuits that enter the absorption GCHP (generator, condenser and evaporator), the radiant floor circuit and the geothermal circuit, the information is collected by a communications network and data is stored in a database for further reference and analysis. The experimental plant is located in a tertiary-use building in Valladolid (Spain). A model of the experimental installation has been developed using the TRNSYS software. The model has been validated with experimental results obtained in the installation for its cooling mode operation during the summer of 2011. For a defined control strategy, the influence of the generator and condenser temperatures on the heat pump COP and on the overall system energy efficiency is analyzed. (C) 2013 Elsevier B.V. All rights reserved.