Google has added additional device types to its Smart Home API used by Google Assistant, including a “fan” type that is a much better representation than the switch that HA is currently using. This allows using additional properties such as fan speed when controlling the device from Google Assistant.
Ref: https://developers.google.com/actions/smarthome/guides/fan
In particular, this enhancement would work quite well with the GE/Jasco Z-Wave Smart Fan Control.
It would be great for the Hampton bay wink enabled fan controller too…
For specifics… I took a look at the google_assistant/trait.py code (HomeAssistant .78) It does have fan implemented, but only the OnOff Trait, which probably causes google assistant to see it as a switch instead of a fan. It needs to implement the action.devices.traits.FanSpeed trait. In contrast, Alexa (alexa/smart_home.py) does have fan speed traits (low/medium/high) implemented.
Ack - I just stumbled across this looking for a solution as to why my fan can only turn on/off with Google Assistant. Anyone know if anyone is working on this?
This is implemented