What was found
DURING CLIMB OUT OF BWI, WE BRIEFLY EXPERIENCE A WET SOCK ODOR, BUT WENT AWAY. DESCENDING INTO MCO THE STRONG ODOR RETURN (MODERATE INTENSITY) WE TRY TO ISOLATE PACK #1 FOR FEW MINUTES, THEN PACK #2 AS PER QRH. BUT WE COULDNT ISOLATE THE ODOR. THE INTESITY SLIGHTLY DIMINISHED AFTER LANDING. -IN REF TO TSM 05-50-00-810-831-A. FOUND APU AS THE SOURCE OF THE FUME EVENT. REF LP 3577548-2. FOR APU DEFERRAL. A/C OK FOR CONTINUED SERVICE. NO MORE ODORS AFTER APU FOUND AS SOURCE OF FUME EVENT. DESCRIPTION OF ODOR/FUMES: PERSISTENT, DIRTY SOCKS SMELL. APPARENT CABIN SOURCE: CABIN AIR SUPPLY VENTS. FLIGHT DECK, FWD CABIN, MID CABIN, AND AFT CABIN. NO VISIBLE SMOKE/HAZE. NO MEDICAL ATTENTION REQUIRED.