Abstract: An air curtain (18) for an air handler (12) is disclosed for moving to block air from passing through selected cooling coils (14). The cooling coils (14) are separated into separate sections (1-4) along a lineal direction (22), with the separate sections (1-4) connected to respective compressors (52), condensers (54), and expansion valves (56). The air curtain (18) is located on one side of the cooling coils (14) and furled into a housing (16) to provide full flow airflow through all the separate cooling coil sections (1-4). The air curtain (18) unfurls along the lineal direction (22) to block airflow (46) through selected sections (1-4) of the cooling coils (14). Position sensors (24-30) are mounted in registration with edge regions (32) of the cooling coil sections (1-4) and detect when a terminal end (20) of the air curtain (18) is proximate to respective ones of the positions sensors (24-30).