Experimental examination of heat transfer coefficients in hydronic radiant wall cooling systems

Koca A.

Journal of Building Engineering, vol.60, 2022 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 60
  • Publication Date: 2022
  • Doi Number: 10.1016/j.jobe.2022.105209
  • Journal Name: Journal of Building Engineering
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, INSPEC
  • Keywords: Radiant wall, Radiant cooling, Radiant systems, Heat transfer coefficient, Thermal comfort
  • Istanbul Technical University Affiliated: Yes


© 2022 Elsevier LtdRadiant heated and cooled wall systems may offer benefits like building retrofitability, architectural flexibility, a comfortable thermal atmosphere, and compatibility with alternative energy sources. In certain situations, radiant wall systems are preferable to floor and ceiling systems due to their benefits. In this study, a set of tests were performed in order to assess the heat transfer features of the hydronic radiant wall cooling system. A climatic test chamber was constructed for this objective, and convection, radiation, and total heat transfer coefficients (HTCs) were evaluated and analyzed. For the purpose of calculating the HTCs, experiments were conducted at various supplied water temperatures. The HTCs were then estimated using the corresponding characteristic temperature differences. The total, radiation, and convection HTCs for the cooled radiant wall were found to have estimated mean values of 8.25, 5.52, and 2.41 W m−2.K−1, respectively. Radiation contributes to around 70% of the overall heat transfer on average. Additionally, two different radiant panel arrangements were tested to examine how the thermal conductive layer influenced the thermal performance of the cooled radiant panels. The cooling capacity of the panel with an aluminum conductive layer is about 21% more than that of the traditional panel.