Air filters + variable-speed drives. Camfil and ABB distributor IDS have just teamed up to offer variable-speed drives and air filters for air handling units. They claim energy savings of up to 50 percent are possible with a payback in about 12 months. Other benefits claimed include less employee absenteeism and higher worker productivity through the cleaner air, fewer maintenance intervals, less waste and lower CO2. The key is to get the message into the boardroom. And that message according to Bill Wilkinson of Camfil: "This is the easiest way to save money."