I know our roof has an overhang gap that is only closed by the soffit, you can see the light through the gaps when you go up there during the day. We do also have a fireplace, and like I said there's definitely air leaks around the trim (even though the windows themselves are supposed to be energy efficient). No clue where our exhaust intake is, so that's a no go, unless you're talking about the spot where the filter is? If thats the case its right outside our bedroom door, and it has pretty good suction. We have to keep on top of the filters with all the critters and my allergies. They also completed replaced our heatpump right before we moved in as it didn't pass inspection and it was cheaper for them to replace it than it was to repair it.
