Comprehensive energy and techno-economic analysis of ductless and ducted split air-conditioning systems for a healthcare facility in an arid climate

Heating, ventilation, and air-conditioning (HVAC) systems are critical in healthcare facilities due to their role in ensuring thermal comfort, indoor air quality, and continuous operation with high energy efficiency. Among commonly adopted solutions, ductless mini-split air-conditioning systems serve individual zones, while ducted split systems distribute conditioned air to multiple spaces through duct networks. Despite their widespread use, a direct techno-economic comparison of these systems for hospital applications in arid regions, particularly in Afghanistan, has not previously been reported. This study presents the first comprehensive energy and techno-economic comparison of ductless and ducted split air-conditioning systems for a hospital building in Afghanistan. Heating and cooling loads were calculated using the Hourly Analysis Program (HAP 5.1) in accordance with ASHRAE standards, incorporating detailed building geometry, construction materials, occupancy schedules, and local climatic conditions for Kandahar. The maximum cooling and heating loads were found to be 293.8 kW and 79.3 kW, respectively. To meet these demands, the ductless mini-split configuration required 61 units with a combined power demand of 107.9 kW, whereas the ducted split system achieved equivalent thermal performance using only 10 units with a lower total power demand of 102.3 kW. A techno-economic assessment revealed that the ducted split system resulted in a lower initial investment cost ($22,000.65) compared to the ductless mini-split system ($28,153.93), in addition to substantial annual energy and operating cost savings under local electricity tariff conditions. The reduced number of units, improved load aggregation, and enhanced part-load performance contributed to the superior efficiency of the ducted configuration. The findings demonstrate that ducted split air-conditioning systems offer a more energy-efficient and cost-effective solution for hospital buildings in hot arid climates. This work provides novel, location-specific evidence to support sustainable HVAC system selection for healthcare facilities in Afghanistan and regions with similar climatic and operational conditions. • Comparative analysis of ductless split AC systems and ducted split AC systems in a hospital. • Cooling and heating loads calculated using HAP 5.1 with real building data. • Ducted split AC system required fewer units, lower capital cost, and reduced energy use. • Findings support sustainable HVAC design for hospitals in arid climates.