Several national

Several national firms began marketing controversial air duct cleaning/encapsulating techniques in the late 1980's as an alternative to vacuum systems. The idea has been to trap and hold trapped dirt and spores. The use of sometimes questionable materials and the poor effectiveness of the procedure brought several Florida counties to require HVAC (heating, ventilation, air conditioning) licenses for contractors performing air duct cleaning services. • The use of sanitizing solutions to kill mold and bacteriological growth opens the question of safety for humans and pets in the air conditioned