Every room with Smart Vents needs a temperature sensor. An integrated smart thermostat or its room sensors can be used in place of a Flair Puck to read the temperature and also provide occupancy data.
If you decide to use a smart thermostat and/or room sensor in a room with Smart Vents, please read this article to determine how many Gateway Pucks you may need for your system, as your installation may require more than one.
A room sensor cannot be used to control a mini split, window AC, or portable.
* See What smart thermostats and room sensors are supported?