The SmartCocoon device is not designed to block airflow completely. However, when the fans are not running, the device can reduce airflow through the vent by up to approximately 70%.
In normal operation, once the room reaches the desired temperature, the SmartCocoon fans will stop, even if the main HVAC system is still running. This helps redirect more conditioned air to other rooms in the home that may still require heating or cooling.
Please note that completely blocking airflow in a large number of vents is generally not recommended. Restricting airflow in more than approximately 30% of the vents in a home can increase static pressure within the duct system and may negatively impact the performance and longevity of the HVAC equipment.