Prediction of Indoor Airflow and Contaminant Transport in Office with Coupled Displacement Ventilation and Ceiling Radiant Cooling Panel

Abstract

In this research, an experimental and numerical analysis have been conducted to predict the temperature, velocity distribution, and contaminant concentration in indoor spaces conditioned with corrugated ceiling radiant cooling panel (RCP) and Displacement Ventilation. The experiments were done on a model room with dimensions of (1.6m×1.2m×0.8m) built according to a suitable scale factor (1/5) to simulate the temperature, velocity distribution, and CO2 concentration by 36 measuring devices in an array scheme in three different zones and heights. Two cases were considered in this work, the first was with chilled ceiling panels only (without ventilation) and the second was with displacement ventilation. The experiments primary variable was the mean panel temperature (Tmp) with values of (15, 16, and 17oC). The second experimental cases were taken with an air inlet temperature of 24oC and a velocity of 0.7m/s with a range of outdoor air temperatures of (36 to 42oC). A computational fluid dynamics (CFD) program was built up to simulate air distribution in an enclosed environment with the DV-PCB system, which was then validated by the measured data. The validated CFD model was employed to analyze thermal comfort and indoor air quality in the enclosed environment with the DV-PCB coupled system using four indices: vertical temperature gradient, draft rate, normalized contaminant concentration, and age of air. The results indicate that CRCP is quite effective in reducing the temperature gradient created by DV. The results show that there is an enhancement in the total cooling capacity. Most of the computed results were presented as temperature contours and velocity vectors diagrams compared with the experimental work. The comparisons show a reasonably good agreement. Both experimental and numerical studies assist RCP for cooling purposes in the Iraqi climate for its ease, simplicity, and good comfort performance.