Workplace climates come clean with CLEANPAK International. The company manufactures various types of air handling equipment. Its emphasis is on specialized products, such as fan filters and re-circulating air handlers used in high-tech clean rooms. CLEANPAK also makes the requisite ceiling systems for clean rooms, and modular buildings housing electrical equipment. In 2006 NTK Holdings' subsidiary Nortek, Inc. acquired CLEANPAK. CLEANPAK has since operated as part of Nortek's commercial HVAC systems segment, CES Group Inc. On-going weak demand forced Nortek and its affiliates, including CLEANPAK, to file a prepackaged plan of reorganization under Chapter 11 bankruptcy in 2009. Emergence followed 57 days later.