Sustainable greenhouse climate management using solar-assisted adsorption air-conditioning system in hot-humid climates

Increasing global food demand drives greenhouse expansion in the tropical and subtropical regions, where high solar radiation and elevated temperatures present substantial cooling challenges. Traditional systems like evaporative fan pads struggle with high ambient wet bulb temperatures, while vapor-compression systems incur high energy costs and carbon emissions. This study, the first of its kind to comprehensively evaluate adsorption-based cooling for greenhouse climate control in hot-humid US regions, explores system performance in Miami (ASHRAE 1A) and Houston (ASHRAE 2A). The Findings show that the air-side enthalpy economizing strategy can reduce cooling demands in hot-humid climates. Comparatively smaller buffer tank of 40 L/m 2 turned out to be optimal for the case study greenhouse (330 m 2 ) in Miami, whereas about 80 L/m 2 in Houston. Under the baseline solar collector configuration (sized to achieve a solar fraction of 0.5 during the peak cooling month of July), the levelized annual cooling costs were $99.7 /m 2 for Miami and $83.6 /m 2 for Houston, with corresponding emission footprints of 103 kgCO 2 e/m 2 and 74 kgCO 2 e/m 2 , respectively. Increasing the collector area beyond the baseline configuration led to emission reductions of up to 24% in Miami and 23% in Houston, highlighting the environmental benefit of higher solar integration despite associated capital cost increases. While the results demonstrate the potential for solar thermal adsorption systems to sustainably cool high-tech greenhouses in hot-humid climates, the high capital investment required for adsorption chillers remains a significant barrier to widespread adoption. • Solar-powered adsorption system evaluated for hot and humid regions. • Greenhouse thermal model developed using TRNSYS and validated using experimental data. • Enthalpy and air-side economizer savings ranged between 10%–60% depending on locations and time. • Solar fraction for heating and cooling ranged from 0.4 to 1.0, depending on session 8 and collector areas. • Levelized annual costs were 99.7 $/m 2 in Miami and 83.6 $/m 2 in Huston. • Lowest emissions at high collector area: 78.3 (Miami), 57.0 (Houston) kgCO 2 e/m 2 .