I'm remodeling a simple 3 piece bathroom. It has a window in the middle but no exhaust fan. I want to put the exhaust fan on the exterior wall, so it's a simple install. But it will be within 1' from the window. Some HVAC guys told me code is that a vent has to be 3' from a window. I could see that for a sewer/furnace vent. Does this 3' code apply to an exhaust fan that will be blowing moisture?