THE INFLUENCE OF CHILLED WATER TEMPERATURE AND COOLING SURFACESON THERMAL COMFORT OF RADIANT COOLING SYSTEM
The influence of supply water temperature on the indoor thermal comfort of a radiant cooling system, i.e., a room with thermally activated glass fibre reinforced gypsum (TAGFRG roof) is studied. The supply water temperature is varied from 18 to 26°C with an interval of 2°C. The No Cooling (NC) case, i.e., the cooling system is shut down, is also investigated. A water chiller with a thermostat switch supplies water at the required temperature. The surface (area) employed for cooling has a considerable impact on the performance of the radiant cooling system. The cooling area is increased by employing more surfaces(walls and floor) for cooling. The piping to each surface has an individual valve to control the flow rate of the chilled water. Four cases of cooling surface combinations are studied, namely, Roof only (R), Roof and Floor (RF), Roof, Floor and 2 Walls (RF_2W), and All Surfaces (AS). In the RF_2W case, chilled water is supplied to the north and south walls. NC case is also investigated. For R, RF, RF_2W and AS cases, the cooling surface areas are 9, 18, 31.2 and 47.4 m2, respectively. It is a well-established fact that an increase in cooling surface area would increase the heat transfer. In this study, the supply water temperature and the heat load are maintained at 20°C and 400 W (44.4 W/m2).
Steps to reproduce
Indoor and outdoor surfaces and air temperatures, relative humidity and supply water temperature are measured for one min time interval using the datalogger. The thermocouple numbering and position are listed in the excel sheet. The collected data were post-processed using a Matlab code to calculate the thermal comfort parameters and then averaged it for one hour time interval.