Looked at a boiler room for a house with an indoor pool new owner, burning too much fuel.
I had to walk around the building thru a foot of snow to get to the room. I could have drove my truck in, if only I had known the room had a gaping combustible air hole in the outside wall.
Yes, combustible air is a necessity, but the burners need the air, not the room.
There are alternative methods of delivering fresh air directly to the oil burners instead of flooding the entire room with outside air. This air is pretty darn cold, otherwise you wouldn’t have your heat on. Why have cold outside air all around your heating system?