Comfort aspects in buildings supplied by radiant systems with mechanical ventilation

The purpose of HVAC systems in buildings is to provide comfortable conditions in indoor environments. Their interaction with the room depends on the working principle and the mode they exchange sensible and latent heat with the indoor environment. This work aims to focus on these aspects and investigate how different systems affect the indoor parameters that contribute to indoor thermal comfort perception. Some experiments were carried out in cooling conditions in a test room with different solutions: the room was cooled through the presence of the radiant ceiling alone, the mechanical ventilation alone and the simultaneous presence of the two systems. The results showed the difference in impact between the two systems: the ventilation causes a fast decrease in the air temperature and has little effect on mean radiant temperature; the radiant cooling system presents a higher inertia and a more relevant effect on the radiant temperature. A modeling activity was also conducted, comparing the simulation results with the measurements. The model was found to represent the room adequately in all the tested cases, and it can be used for predictions and long-term energy simulations for evaluating the energy aspects and comparing the different systems.