Experimental Study on Heat Transfer Coefficients in an Office Room with a Radiant Ceiling During Low Heating Loads

Estimation of the heating or cooling capacity of radiant systems requires selecting appropriate internal heat transfer coefficients by convection (CHTCs) and radiation (RHTCs). Due to practical reasons, their measurement during the normal use of buildings is very troublesome. This study attempts to...

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Main Author: Piotr Michalak
Format: Article
Language:English
Published: MDPI AG 2025-03-01
Series:Energies
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Online Access:https://www.mdpi.com/1996-1073/18/7/1591
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author Piotr Michalak
author_facet Piotr Michalak
author_sort Piotr Michalak
collection DOAJ
description Estimation of the heating or cooling capacity of radiant systems requires selecting appropriate internal heat transfer coefficients by convection (CHTCs) and radiation (RHTCs). Due to practical reasons, their measurement during the normal use of buildings is very troublesome. This study attempts to present the results of measurements of CHTCs and RHTCs taken in an office room located in a passive building with a heated concrete ceiling. Special attention was paid to the proper choice of reference temperatures. For better accuracy, view factors for radiant heat exchange were calculated using Matlab. Average values of CHTCs and RHTCs calculated from measurements amounted to 0.80 W/m<sup>2</sup>K and 5.66 W/m<sup>2</sup>K. RHTCs showed a significant correlation against the ceiling temperature, with the coefficient of determination being R<sup>2</sup> = 0.96. Finally, the total heat transfer coefficient of 6.47 W/m<sup>2</sup>K was obtained. These values are comparable with other studies and standards and confirm that measurements were performed correctly.
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spelling doaj-art-e75af2419c734efe86aa8c6d3464f29b2025-08-20T02:09:13ZengMDPI AGEnergies1996-10732025-03-01187159110.3390/en18071591Experimental Study on Heat Transfer Coefficients in an Office Room with a Radiant Ceiling During Low Heating LoadsPiotr Michalak0Department of Power Systems and Environmental Protection Facilities, Faculty of Mechanical Engineering and Robotics, AGH University of Krakow, al. A. Mickiewicza 30, 30-059 Krakow, PolandEstimation of the heating or cooling capacity of radiant systems requires selecting appropriate internal heat transfer coefficients by convection (CHTCs) and radiation (RHTCs). Due to practical reasons, their measurement during the normal use of buildings is very troublesome. This study attempts to present the results of measurements of CHTCs and RHTCs taken in an office room located in a passive building with a heated concrete ceiling. Special attention was paid to the proper choice of reference temperatures. For better accuracy, view factors for radiant heat exchange were calculated using Matlab. Average values of CHTCs and RHTCs calculated from measurements amounted to 0.80 W/m<sup>2</sup>K and 5.66 W/m<sup>2</sup>K. RHTCs showed a significant correlation against the ceiling temperature, with the coefficient of determination being R<sup>2</sup> = 0.96. Finally, the total heat transfer coefficient of 6.47 W/m<sup>2</sup>K was obtained. These values are comparable with other studies and standards and confirm that measurements were performed correctly.https://www.mdpi.com/1996-1073/18/7/1591heat transfer coefficientconvectionradiationheat flux measurementconcrete ceiling heating
spellingShingle Piotr Michalak
Experimental Study on Heat Transfer Coefficients in an Office Room with a Radiant Ceiling During Low Heating Loads
Energies
heat transfer coefficient
convection
radiation
heat flux measurement
concrete ceiling heating
title Experimental Study on Heat Transfer Coefficients in an Office Room with a Radiant Ceiling During Low Heating Loads
title_full Experimental Study on Heat Transfer Coefficients in an Office Room with a Radiant Ceiling During Low Heating Loads
title_fullStr Experimental Study on Heat Transfer Coefficients in an Office Room with a Radiant Ceiling During Low Heating Loads
title_full_unstemmed Experimental Study on Heat Transfer Coefficients in an Office Room with a Radiant Ceiling During Low Heating Loads
title_short Experimental Study on Heat Transfer Coefficients in an Office Room with a Radiant Ceiling During Low Heating Loads
title_sort experimental study on heat transfer coefficients in an office room with a radiant ceiling during low heating loads
topic heat transfer coefficient
convection
radiation
heat flux measurement
concrete ceiling heating
url https://www.mdpi.com/1996-1073/18/7/1591
work_keys_str_mv AT piotrmichalak experimentalstudyonheattransfercoefficientsinanofficeroomwitharadiantceilingduringlowheatingloads