Rensa Filtration, a company backed by Audax Private Equity, has completed the acquisition of IREMA-Filter GmbH in Germany and its U.S. subsidiary Aeolus Filter Corporation. This strategic move brings together Rensa’s extensive manufacturing and distribution network with IREMA’s half-century of expertise in advanced filter media technologies and Aeolus’s strong presence in North Carolina.
Founded 50 years ago near Postbauer-Heng, IREMA developed patented methods for producing polymeric microfibers and nanofibers. These fibers can be layered, mixed, and arranged in gradient structures to create filter media that capture fine particles while maximizing dust-holding capacity. The fully polymeric composition resists moisture, maintains mechanical strength, and prevents microbial growth. Finished filters can then be recycled or sent to waste-to-energy facilities, reducing environmental impact.
Aeolus Filter, based in Archdale, North Carolina, applies IREMA’s media and pleating innovations to serve critical data center and healthcare markets. By automating and precision-pleating these high-performance materials, Aeolus delivers filters that support clean air requirements in sensitive environments—ensuring airflow, contaminant control, and regulatory compliance.
Fine particulate matter smaller than 2.5 microns poses significant health risks and is tracked by global air quality standards. IREMA’s nanofiber depth-loading media achieves high efficiency against PM2.5 and submicron contaminants, extending filter life and cutting energy use compared with traditional mechanical filters.
Under Rensa’s ownership, both IREMA and Aeolus will maintain their existing operations and leadership teams. The combined company plans to invest in expanded production capacity for microfiber and nanofiber lines, accelerate research into next-generation filter structures, and leverage Rensa’s sales channels to reach new markets in Europe, North America, and beyond.
This acquisition reinforces Rensa’s position as a leading provider of mission-critical air filtration solutions. By uniting Rensa’s scalable manufacturing footprint and distribution expertise with IREMA’s media innovation and Aeolus’s specialized fabrication, the company is poised to offer a broader portfolio of filters that meet the evolving demands of data centers, hospitals, industrial facilities, and commercial buildings.
Financial terms of the transaction were not disclosed.
Advisors: Baird and Harris Williams served as advisors to the buyer, while Stephens Inc. advised the seller on the transaction. Ropes & Gray and Oppenhoff provided legal counsel to Rensa, while CMS served in the same capacity for the seller.
KEY QUOTES:
“We’re excited to partner with the IREMA and Aeolus management team, employees and their customers. The filtration market has long held the IREMA/Aeolus business and filter technology in high regard, and we look forward to supporting their continued technology development, increased manufacturing capacity and commercial growth. This investment in IREMA underscores Rensa’s commitment to quality and innovation.”
Brandon Ost, CEO and Founder of Rensa Filtration
“Rensa Filtration is the ideal partner for us. Their track record in mission critical filtration applications and focus on innovative solutions is a great fit for IREMA’s core competencies and unique technologies. We are excited to be a part of the Rensa family and together we will seek to drive innovation and growth even faster.”
Dr. Andreas Seeberger, CEO of the IREMA group
The acquisition marks the ninth acquisition since Audax invested in Rensa in 2022. “This acquisition checks a number of boxes for Rensa. Beyond building out the company’s solution set and extending its footprint into Europe, the combination of Rensa, IREMA and Aeolus Filter enhances the value proposition to customers seeking a range of high-quality, innovative solutions.”
Joe Rogers, a partner at Audax Private Equity
“It was exciting to accompany and support IREMA on this phase of further internationalization and growth. Rensa is a compelling fit to seize the business opportunities in both, the European and the U.S. market.”
Herbert Seggewiss, a Managing Partner of PINOVA Capital
