Indoor CO₂ capture driven energy load reduction and ventilation management for plus energy building applications

This study proposes a CO₂ capture-integrated energy recovery ventilation (CERV) system equipped with a CO₂ capture filter, which enables continuous CO₂ removal and ventilation energy load reduction. It allows for a reduced ventilation rate and offers the potential for additional energy load reduction. The maximum CO₂ capture capacity in low-concentration CO₂ condition (2000 ppm) is 2.8 mmol/g and high-performance maintenance (>99 %) is rated in 20 cycle test. The simulation of indoor CO₂ concentration and energy load variation is conducted by adapting experimental performance of the adsorbent and indoor variable conditions to CO₂ feedback algorithm. An evaluation of the impact of indoor variable conditions was conducted and the annual heating and cooling load was reduced by 52.6 % and 27.9 % in optimal conditions compared to conventional energy recovery ventilation (ERV) system. The impact factors that significantly influence changes in energy load are the input mass of adsorbent and the application of optimal regeneration time. In the cost-effectiveness analysis, the break-even point occurs after approximately six years with consideration of installation and adsorbent replacement costs. This study demonstrates the potential applicability of a sustainable indoor CO₂ reduction system and proposes a methodology for indoor application by simulating the material level research findings.