Investigation of thermal comfort performance and optimization of a novel refrigerant-heated radiator

Abstract

In this study, a novel refrigerant-heated radiator (RHR) was introduced and a computational fluid dynamics (CFD) model was developed to investigate the influence of RHR structure parameters on indoor thermal comfort under heating and cooling conditions. Results show that the heating capacity and thermal comfort are improved with the increase of length-to-height ratio, while the thermal comfort is infringed if the length-to-height ratio is too large in cooling conditions. The length-to-height ratio of the RHR with 2.22–3.71 is recommended to meet the thermal comfort requirements in heating and cooling conditions. Comparisons were made between the RHR and air conditioner on indoor thermal comfort, which indicates that the RHR has a better thermal comfort in heating conditions in terms of temperature field, velocity field and thermal comfort indices. Under cooling conditions, the air conditioner has lower temperature distribution and more uniform vertical temperature distribution in human activity area, while the RHR has the excellent performance in the velocity distribution and thermal comfort indices. The findings show RHR has a better thermal performance than air conditioners in terms of overall thermal comfort. The research provides a guide to the benefit of RHR and improves the thermal comfort of ASHP system.