Direct vent heating units with less than 50,000 BTUs may be vented at least how far from a window?

The regulations regarding direct vent heating units specify that units with an output of less than 50,000 BTUs must maintain a minimum distance from operable windows to ensure adequate safety and to prevent any potential hazards associated with combustion gases. The appropriate distance is set at 9 inches, which serves to minimize the risk of combustion byproducts re-entering the building through open windows. This guideline is important for maintaining indoor air quality and protecting occupants from harmful emissions.