Roof Vent Tile for Shower Extractor

[pring_ing]

Hi folks. Currently getting a new shower room fitted. I have an extractor fan that can be set to 15L/second or 21L/second - https://www.cnmonline.co.uk/xpelair-simply-silent-...

Builder has suggested using a vent tile to match the plain tiles in my roof - something like https://timloc.co.uk/products/rtv-p-plain-roof-til... - which has a Free ventilation area of 7,000mm2. I'm not sure that's enough though for the air flow required?

Does anyone have a recommendation for what roof vent tile they'd use for a shower extractor running at 15L/second? Or would you just use pipe or something sticking out the roof?

[Rough101]

It has more free area than your duct will, and is fine.

Keep flexible ducting as short as possible for minimum resistance