What was found
(CAN) FLIGHT CREW SAW AND SMELLED SMOKE IN THE CABIN 5 MINUTES AFTER TAKEOFF FROM AIRPORT. ACFT RETURNED TO AIRPORT. MAINTENANCE CREW RAN ACFT WITH NO FAULTS FOUND. DUST WAS REMOVED FROM CABIN TEMP CONTROLLER. TEST FLIGHT COMPLETED WITH NO FAULTS FOUNDS. MAINTENANCE SUSPECTS THAT DUE TO LOW CABIN TEMPERATURE THE HEATING SYSTEM CALLED FOR FULL HEAT THAT WARMED UP THE THE DUCTING CAUSING THE SMOKE AND ODOR.