This interactive 3D model of an office air handler needs JavaScript. It shows one variable-air-volume air handler serving ten zones on a 25,000 square foot floor: free cooling with outdoor air on a mild day, 57 tons of cooling on a July afternoon, and boxes reheating on a January morning. It then shows what thirteen common air-side faults, such as a locked-out economizer, fighting coils, setpoints that never reset and an air handler scheduled around the clock, add to the bill. Read about each fault in the air handler section of the Pelorus fault library.