What was found
CREW THOUGHT PROBLEM WAS IN ECU. ENROUTE, PILOT FLYING HAD THE ENVIRONMENTAL CONTROLS SET TO THE AUTO MODE. ON LANDING NOTICED CABIN TEMPERATURE STARTED TO INCREASE. NOTICED ON CLIMB OUT, CABIN TEMPERATURE WAS GETTING QUITE WARM. LEVELED OFF AT CRUISE, CABIN TEMPERATURE WAS NORMAL. ON APPROACH, PILOT NOTICED CABIN TEMPERATURE WAS STARTING TO GET WARM AGAIN. ON LANDING, COPILOT STATED IT WAS STARTING TO GET FOGGY IN COCKPIT. SAW THICK SMOKE IN CABIN. PILOT TURNED OFF THE ENVIRONMENTAL SYS AND DEPRESSURIZED ACFT TO REMOVE SMOKE. SHUTDOWN ENGINES AND EVACUATED ACFT. MX TROUBLESHOT PROBLEM DOWN TO GROUND BLOWER FOR ENVIRONMENTAL SYS.