Demand for consumer water purification and air cleaning systems is projected to increase 4.4 percent per year to $1.5 billion in 2012. Gains will be driven by consumer concerns about the quality of the air and water in the home, and greater awareness of the healthful and aesthetic benefits of these systems. The aftermarket plays an important role in the industry with sales of replacement filters and membranes forecast to grow 4.8 percent annually through 2012. These and other trends are presented in Consumer Water Purification & Air Cleaning Systems, a new study from The Freedonia Group, Inc., a Cleveland-based industry research firm.