Effects of Commercial Fin Patterns to Air-side Performance of Outdoor Air Unit (OAU) for Operating Room during Dehumidification in Tropical Region

The design of the outdoor air unit (OAU) for the operating room is always challenging in tropical countries where they should be operated in a wide range of humidity. In this study, the design of the cooling coil for the outdoor air unit has performed with its performance to satisfy the national and international guidelines. The geometrical details of each component and the air-side performance of the OAU main cooling coil are obtained from calculation results performed in commercial software and then validated with experimental results. The validation results show that they are in good agreement for total cooling capacity and sensible cooling capacity within the bound of error of ±7.5% and ±10.0% respectively. Therefore, the condensation rate data validation results show a wider band of error of ±15.0% to cover all experimental results especially for the condensation rate higher that 6 kg/hr. The effects of five different fin patterns on the air-side performance of the OAU main cooling coil are investigated. Based on the determined conditions, the pyramid fin pattern provides the highest total cooling capacity with slightly higher than the corrugated fin. Louvred fin pattern performs the highest sensible cooling capacity and the highest sensible heat ratio among five fin patterns, and pyramids give the lowest. For the condensation rate, the pyramid fin pattern demonstrates the highest value among the rest but slightly higher than the smooth fin. The obtained result from this study is interesting that the pyramid fin pattern demonstrates the highest performance in dehumidifying application.