KINERJA MESIN PEMANEN AIR DARI UDARA PADA BERBAGAI POSISI EVAPORATOR KOIL DENGAN SISTEM KONVEKSI ALAMI

Atmospheric water harvesting (AWH) offers a promising approach for freshwater production by extracting moisture from ambient air through condensation. However, previous AWH studies have primarily focused on system operating parameters and evaporator configurations, while the specific influence of evaporator orientation under natural convection conditions remains insufficiently investigated. This study addresses this gap by experimentally evaluating the effect of evaporator position on the performance of an AWH system using three coil orientations: horizontal, 45° inclined, and vertical. The novelty of this study lies in the systematic comparison of evaporator orientation under identical natural-convection operating conditions, with performance evaluated based on freshwater production, coefficient of performance (COP), heat absorption rate, and evaporator efficiency. The results showed that the horizontal configuration produced the highest freshwater yield of 0.511 kg during 7 h of operation, followed by the inclined configuration (0.494 kg) and vertical configuration (0.476 kg). The horizontal orientation also achieved the highest COP of 5.18, indicating superior system performance under the tested conditions. The improved performance is associated with more effective condensate drainage and utilization of the evaporator surface for moisture condensation. These findings demonstrate that evaporator orientation is an important design parameter for natural-convection AWH systems. The study contributes experimentally based guidance for optimizing evaporator placement as a simple design strategy to improve freshwater production and thermodynamic performance.