Valhalla and Hawthorne responded to 400 Columbus Ave for an activated fire alarm. Upon units arrivals they found that an employee pulled an alarm box because he saw smoke coming from an air conditioner compressor unit. The unit was leaking freon and oil had spilled everywhere. The power was shut down to the unit and the freon leak stopped. Workers were returned as soon as the freon and carbon monoxide levels went down. 2482, 2193, Tower Ladder 49, Engine 84, and Ladder 56 were on scene.