A device for isolating dryer exhaust lines. The device can be attached between a dryer exhaust and an exterior dryer vent. The device has a door that slides between an upper position allowing the air passage duct between the dryer exhaust and the exterior vent to be open and a closed position which closes the air passage duct. A rod slidable within eye type slits has a handle at one end and is attached to the sliding door at the opposite end. A user can push the rod downward which slides the door to close the air passage duct. Lifting the handle pulls the rod up which causes the door to slide up opening the air passage duct. An electrical safety disconnect switch can disconnect power to the dryer when the door is in a closed position. The safety switch can be turned off allowing the dryer to be powered when the door is in the open position. A whistle can further operate in the device which can turn on when pressure builds up if the dryer is turned on and the door is still in the closed position. The device can be used in multifamily, multistory, and other applications where a common exhaust duct is used to service more than one dryer. The device can prevent odors, smells, heat, condensation that is caused from a neighbors dryer to pass into adjacent dryers that share the same common exhaust duct.
