Carbon dioxide capture from air in buildings – Design and techno-economic feasibility of practical systems

[Geoengineering News]

https://www.sciencedirect.com/science/article/pii/S2212982026000405

Authors: Dominik Heß, Michael Rubin, Roland Dittmeyer

13 February 2026

https://doi.org/10.1016/j.jcou.2026.103351

Highlight

•Systematic assessment of the integration of DAC into existing ventilation infrastructure.

•In depth modelling of building integrated DAC with dynamic input parameters.

•Results show that building type and operation strategy do substantially influence energy demand.

•Techno-economic analysis revealed levelized cost of DAC as low as 280 EUR per ton of CO2 captured.

Abstract

Direct Air Capture (DAC) is needed alongside other CO2 removal methods to ensure that the total amount of CO2 required is removed from the atmosphere so that global warming can be limited to below 2 °. While large-scale DAC farms are a promising solution, their high CAPEX and OPEX, along with societal concerns, may hinder widespread deployment. This study presents a novel, modular DAC concept designed for integration into heating, ventilation, and air conditioning (HVAC) systems of buildings. A prototype was engineered and modeled in MATLAB to analyze key physical processes in the adsorber bed using two amine-based adsorbents. A linear driving force model was applied to simulate mass transport, and the DAC unit was coupled with an HVAC system in Simulink to evaluate CO₂ capture from indoor air. Solar thermal energy with thermal storage was defined as the heat source. Optimization results indicate a 40 % reduction in thermal energy demand compared to separate DAC and HVAC systems. Cold, humid air improves CO₂ capture, while dry air significantly lowers the energy demand – up to 50 % when reducing humidity from 90 % to 10 %. A techno-economic analysis suggests that mass-produced DAC modules for HVAC systems could achieve levelized costs of DAC as low as 280 € per ton CO2, particularly when waste heat is utilized. Implementation in densely occupied buildings may yield additional savings of up to 9 %. This work highlights the potential of HVAC-integrated DAC systems as a scalable, cost-effective complement to centralized DAC facilities.

Source: ScienceDirect