Indoor Thermal Environment Generated by Convective and Radiant Systems

The design of indoor climate systems in modern office buildings should enable comfortable and productive indoor environment for occupants. The objective of the thesis has been to investigate the performance of convective, radiant and combined indoor climate systems with regard to thermal environment. Studied systems included chilled beam and chilled ceiling with mixing ventilation, chilled beam integrated with radiant panel and also research of a novel experimental radiant cooling unit. Thermal environment was assessed by measurements using advanced instruments including thermal manikins in simulated office spaces with different heat load levels and room layouts. One significant finding in this research was the small difference in thermal environment between different cooling systems.Other significant finding was the performance of chilled ceiling with mixing ventilation providing the most uniform thermal environment regardless of the workstation layout as part of comprehensive analysis of the characteristics of different cooling systems generating thermal environment. The effects of air distribution and heat load arrangement on the cooling performance of the ceiling radiant panels were studied in the other part of the thesis. The increase of the cooling power with different supply air distribution and heat load types were revealed. The thermal environment and the performance of chilled beam integrated with radiant panel in heating mode was studied with both experimental and CFD simulation methods. Thermal comfort conditions in all studied cases were good, still minimum internal window surface temperature in design conditions was found for the most advantageous conditions. That can be easily achieved with modern window construction.