I have become a firm believer in scent control and high vents. When I rebuilt a 4X4 box blind this year, I had a bunch of 4" drain pipe left from another project and thought what the heck...
I paid extra attention to sealing around the windows and door, then calked the roof to wall transitions. One vent (closable) at the bottom and 25' of riser above the roof. It is amazing! I have had deer downwind, within 6 feet of the stand...something that never happened in the previous seasons.
The arrangement drafts so well, I have to keep the bottom vent closed down to about 1/4 of the opening, or it moves too much air.
An unexpected benefit is the new sealed stand is much easier to keep warm in the winter. I find about 10 minutes on and 20 minutes off on my heater is all that is needed in below freezing temps.
NRA Lifer / Member TSRA