I had a lady call me, Her home has a windy whisper sound for about a month now, I have not seen the home yet. Does any one that problem in the past. I am looking for ideas and advise.
Check all exterior vents to the outside. Possibly flapper door on dryer, bathroom ventilation or range vent.
Check the furnace cover/access doors for any gaps that can make a noise when the blower is running.