Performance of an Air-Water Harvester Machine under Various Inlet Air Relative Humidity Conditions

Mirmanto Mirmanto; Made Wirawan; Faniar Reza Khatami; Arif Mulyanto; Yesung Allo Padang; Nurchayati Nurchayati; Jayus Kharisma Hendra

Authors

Mirmanto Mirmanto Universitas Mataram
Made Wirawan
Faniar Reza Khatami
Arif Mulyanto
Yesung Allo Padang
Nurchayati Nurchayati
Jayus Kharisma Hendra

Keywords:

atmospheric water harvesting, evaporator heat transfer, inlet air relative humidity, thermodynamic performance, vapor-compression refrigeration

Abstract

Atmospheric water harvesting (AWH) using vapor-compression refrigeration systems has emerged as a promising approach for decentralized freshwater production. Although previous studies have investigated the effects of refrigeration-system configurations and operating parameters on water production, the influence of inlet air relative humidity on freshwater productivity, heat-transfer characteristics, and thermodynamic performance has not been comprehensively evaluated within a single experimental framework. This study experimentally investigates the performance of an air-water harvester operating at inlet relative humidities of 30%, 50%, and 70% under controlled laboratory conditions. Freshwater production, coefficient of performance (COP), total heat absorbed by the evaporator, and evaporator efficiency were evaluated using measurements of temperature, pressure, airflow velocity, electrical power consumption, and psychrometric properties. The results show that increasing inlet relative humidity significantly enhanced condensation and system performance, yielding the highest freshwater production of 0.345 kg and the maximum COP of 12.19 at 70% RH. In contrast, the highest evaporator efficiency (11.89%) and total heat absorbed by the evaporator (167.81 W) were obtained at 30% RH, where sensible heat transfer dominated the cooling process. The findings indicate that inlet air relative humidity strongly influences the distribution of sensible and latent heat transfer, thereby affecting both freshwater production and energy performance. This study provides an integrated experimental assessment of the thermodynamic response of refrigeration-based AWH systems to varying inlet humidity and offers practical guidance for optimizing system operation in humid tropical environments.

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