Moisture control is essential for maintaining indoor environmental quality, but removing latent heat from air requires substantial energy, making it a major burden on cooling systems in humid climates. This study develops a ventilated, 3D-printed clay wall assembly that passively removes moisture from indoor air. The design operates through two coupled airflow paths separated by a clay medium. Similarly to an Energy Recovery Ventilator (ERV) system, moisture is absorbed from humid incoming air, transported through the clay by vapor diffusion, and released into a separate exhaust airflow. Clay is used because it is a hygroscopic material with high durability and compatibility with additive manufacturing. 3D printing enables precise control of geometry and material thickness and increases the effective absorbing surface area of clay, allowing the system to be tuned for targeted moisture removal performance. A series of controlled tests were conducted to evaluate the influence of surface geometry and thickness on moisture transfer. The results indicate a latent recovery efficiency of approximately 60%, demonstrating the system’s ability to passively remove moisture from the incoming air under controlled conditions. The results from a physical optimized prototype were additionally simulated at the building scale to assess the potential of the system to impact indoor humidity regulation.