Loft/ atic growing!!!

How could I bring air in a sealed loft for my intake?, I know to use the chimney Brest for the intake just the intake is baffling me any ideas guys ?????

There are vents you can buy that replace tiles on the roof and it's a vent you can attach a duct to.
Alternatively you could drill into your bathroom roof and have a fake extractor that's really for your grow.
I dunno be creative!
And unless your very very well insulated those pesky pork choppers in the sky will be coming through your door with a nice early morning wake up call.

i just hired a core drill and went into my chimney