is visa needed for a 15 hr lay over in Guangzhou airport from Canada

We are travelling to Phuket through the Guangzhou airport, do we need a 72 hr free transit or 24 hr direct transit to leave the airport or even to get a room at hotel attached to airport for the 15 hr lay over. Can you advise.
arrive china southern airlines - lay over 15 hrs direct from Canada all canadian passport holders.
thank you