The device can be installed in reverse, allowing it to push air from the room into the return vent rather than pulling air from the duct into the room. This configuration works well when the HVAC system is controlled by a Nest thermostat, as the device will still receive signals from Nest and automatically turn on and off as needed.
However, if you are using a thermostat other than Nest, synchronization may be more challenging. Because the device is not exposed to the airflow from the supply vent in this setup, it may not be able to detect when the HVAC system is running. In such cases, manual operation may be required to ensure the device turns on and off in line with your HVAC system.