The in-duct model is designed to run 24 hours a day. That is not to say that it will. The in-duct model has a sensor that allows the air purifier to run only when the fan is on. In times when the air handler is not on it is recommended to run the fan for 2 hours. When conditions arise such as the presence of odors or chemicals, you can increase the operation time for an additional hour or as needed.
With the portable unit you can operate it for an hour a day or increase the time depending on conditions. You can the easily move it to another room.
Posted in: Air