Experimental evaluation, reduced-order modeling, and HVAC assessment of a metal-foam liquid desiccant contactor

Improving air–solution contact within a compact contactor is a key challenge in liquid-desiccant air-conditioning systems. This study experimentally evaluated an open-cell aluminum-foam contactor using an ionic-liquid desiccant and developed a modeling framework linking component-scale performance to building heating, ventilation, and air-conditioning simulations. The 20-pore-per-inch metal foam was operated under adiabatic two-fluid conditions without internal cooling. Experiments conducted at an inlet air temperature of 34 °C and humidity ratio of 19.5 g kgda −1 demonstrated dehumidification under all tested conditions, although non-uniform solution distribution and partial wetting limited utilization of the nominal surface area. A two-dimensional heat and mass transfer model incorporating an effective wetting ratio reproduced the experimental outlet air temperature and humidity ratio with mean absolute errors of 0.657 °C and 0.503 g kgda −1 , respectively. An effectiveness–number of transfer units based reduced-order model reproduced the parent detailed-model outputs with mean absolute errors of 0.409 °C and 0.192 g kgda −1 , respectively. In a preliminary summer office case study in Tokyo, the liquid-desiccant-assisted configuration reduced the considered heating, ventilation, and air-conditioning subsystem power from 4.83 to 2.82 kW while maintaining 26 °C and 45% relative humidity. The results demonstrate the feasibility of metal foam as a compact liquid-desiccant contactor while identifying effective wetting and liquid distribution as key factors for realizing its surface-area advantage.