Purair Basic Ductless Fume Hoods The Purair® Basic ductless fume hoods are designed to provide high level performance features at an affordable price. Purair Basic ductless hoods are found in research laboratories, educational facilities, and forensic laboratories throughout the world and are designed to protect the user and the environment from hazardous vapors generated on the work surface. At the heart of the Purair fume hoods product line is the innovative Air Science® Multiplex™ Filtration Technology that creates a safe work environment over the widest range of applications in the industry.