At 0733hrs Dorchester Central dispatched units for A "COMMERCIAL BUILDING FIRE" @ 2 Rose Hill Dr. (SAILWINDS VISITOR CENTER) in the Cambridge 1-1 Box Area. Chief 1 arrived on location with an odor and haze in the building and established command. Crews (Engine 1-3, Tower 1 & Talbot Rescue 32) formed investigation group and determined it to be a problem with the air handler. Command placed the situation under control approx. 30 mins later and placed all units in service without incident.