Tandem™ composite air filter media combines a high-performance surface layer of P84® polyimide fibers with conventional filter media for enhanced filtration performance at a fraction of the cost. The P84® top layer, with its multi-lobal fiber construction, provides higher surface area for effective surface filtration and dust cake formation while maintaining high airflow and low pressure drop across the media. The result is a highly efficient filter media with lower energy requirements and high capacity.