Abstract
Direct Air Capture (DAC) technology has gained significant attention as a promising solution for mitigating CO2 emissions and meeting climate goals. However, the current challenges of high energy demand, capital costs, and scalability present critical challenges to the widespread deployment of DAC systems. Integrating DAC with Heating, Ventilation, and Air Conditioning (HVAC) systems in buildings offers a potential solution by enhancing indoor air quality while capturing CO2, thus lowering energy consumption and capital investment compared to standalone DAC systems. This study evaluates the techno-economic performance of an integrated DAC-HVAC system against a standalone DAC system. This analysis combines thermodynamic estimation of CO2 and H2O loadings and energy requirements with an economic evaluation of capital and operating costs to calculate the levelized cost of CO2 capture (LCOD) for both DAC-HVAC and DAC-standalone. A sensitivity analysis explores the effects of varying climatic conditions, specifically temperature and humidity, on the economic performance of the DAC-standalone system. Further sensitivity analysis examines the impact of discount rates and electricity prices on both systems' economic viability. Results show that the DAC-HVAC integration achieves lower energy consumption and capital costs, with an LCOD of approximately 219 $/ton CO2, compared to the DAC-standalone system, which ranges from 349–429 $/ton CO2 depending on climatic conditions. In addition to offering a lower levelized cost, the DAC-HVAC system also provides resilience against climate and cost fluctuations. This study demonstrates the significant economic benefits and scalability potential of integrating DAC technologies within existing building infrastructures.