The typical old Florida house might whistle a bit but I doubt you would really generate any real vacuum.
Well I can't speak for your house but in the 'cold' areas people die every year from CO poisoning, sometimes it is from simple as having an exhaust fan on which drags the flue gases from the oil or gas fired furnaces and boilers back down the flue and into the home.
The fact that you can see it on you barometer kind of proves the point. Now if you had a oil fired boiler in the house with the typical natural draft venting you would have some issues.
The large majority of fuel burning appliances I see are not power vented they use natural drafting, it takes very little 'low pressure' to stop the natural draft.
This is probably not an issue you see in the land of Air conditioning, heat pumps and electric resistance heating
but make no mistake it can be an issue in my area.
