<p>Air pollution is a critical global concern, significantly affecting human health and the environment. Urbanization, industrialization, and population growth have intensified the release of hazardous particles and gases, particularly in developing countries like India, where many cities rank among the most polluted. Filtration is a widely adopted particulate matter (PM) control technology for air purification across various settings. However, studies on ultra-fine particle (UFP) removal efficiency at different face velocities (FVs) remain limited. To address this pressing issue, a systematic investigation is conducted to evaluate the removal efficiency of filtration technology. In this study, eight distinct fibrous media based on their minimum efficiency reporting value (MERV) were employed to assess their effectiveness using a custom-built air filter holder in capturing ultra-fine PM. The primary objective was to assess their performance in trapping sub-micron particles, known for their potential health impacts. The study analyzed filtration efficiency using key metrics such as particle removal efficiency, pressure drop, and quality factor. To evaluate filter performance, UFP penetration was tested across all media at FVs of 0.2, 0.5, and 0.8&#xa0;m/s. The quality factor was also examined to understand the impact of effective fiber diameter, thickness, and solidity on filtration. A single-fiber model for a mechanical filter was applied for theoretical calculations, with model predictions aligning well with experimental results across all tested media. These findings offer valuable insights into selecting suitable fibrous media for air cleaner applications, particularly in environments where controlling UPFs is crucial for air quality and public health.</p> Graphical Abstract <p></p>