Experimental investigation of indoor convective and radiative heat transfer coefficient for a thermally activated building system in tropical climate conditions

Thermally activated building systems (TABS) are one of the most commonly utilised structural cooling methods in construction industries. This method of structural cooling has pipes encapsulated in building surfaces. This investigation analyses the internal convective heat transfer coefficient (CHTC) and radiative heat transfer coefficient (RHTC) for TABS in tropical conditions. The overall heat transfer coefficient is experimentally evaluated with HFP01 heat flux sensors and wet bulb globe thermometers. Calculated and actual CHTC were compared with the interrelationship available in the referred literature and with the constant value recommended by the standard. The results from the measurements indicate that the average CHTC and RHTC are 2.66 W/m²K and 5.7 W/m²K, and it conforms with EN ISO 6946 standards for tropical climates. The CHTC was also quantified with many correlations developed in the scientific literature to determine the best model for the TABS environment. From statistical error analysis, it was determined that Khalifa and Marshall's model was suited with the most minor error of 3 % compared to the other models.