Numerical comparison between energy and comfort performances of radiant heating and cooling systems versus air systems

A comparison between energy performance, simulated by means of the EnergyPlus building simulation program, of two air systems (all air and fan coil) and radiant heating and cooling floors/ceilings is developed in this work for various European climates (Milan, Frankfurt, London, Madrid, Athens, Helsinki, and Moscow) and carried out on a reference building selected from among U.S. Department of Energy commercial building new construction benchmarks. The comparison is focused on the analysis of energy sources and CO2 emissions at equivalent thermal comfort quality levels in the various cases. The adoption of a radiant system, and of an appropriate primary energy system, always results in a reduction of energy sources exploited, of costs for energy wares purchased, and of carbon dioxide emissions. The greatest reductions can be achieved in climates where the energy demand for cooling is greater than the energy demand for heating. The article also focuses on the discussion of the procedure to be adopted when a comparison between air systems and radiant systems is implemented.