We have an open fire, which we use occasionally during the winter. I
rather fancy opening up a vent in the floor, near the hearth, in order
to feed the fire with air from the vent, rather than it sucking draughts
in via the doors to the room.

Does anyone have experience of this? Is my thinking along the right
lines? And what would I look for, at Screwfix, Wickes, etc?

TIA

John