Thank you for your question.
You will not need any extra air vents to fit the Hunter Verona 6 gas stove.
Here's the relevant section from the user manual:
"The supply gas heat input into the appliance is nominally less that 7kw, therefore under the directives of the current gas safety and use regulations (1995) no additional air vents are required in the room the appliance is situated."
you can see the complete user guide in the downloads section on the product page.
Hope this helps?