Flair can support multiple thermostats, and multiple sensors when using integrated thermostats.
In most homes a single Puck is all thats needed if you already have enough remote sensors. However if you have separate systems, you might have a pretty large home/deployment. Use our large system calculator to enter the number of Smart Vents you'll need and then it will calculate the minimum number of Gateway Pucks you'll need: https://flair.co/pages/large-
Note: Based on layout and construction, some homes will require more than one Gateway Puck to facilitate signal to other Flair devices.