Andy, sparks, really?
That's funny, please explain that. I have seen this type of vent on many AS's. As far as I know the burner is enclosed in a metal shroud and has an internal chimney around the heat exchange. How would there be any sparks? I only have a 3-way refer, propain, 110v ac, 12v
dc. If I burned sticks I might believe there could be sparks. This is just a vent for the gas fumes to escape. Granted the fumes are warm/hot, but no where near hot enough for wood combustion 572 degrees Fahrenheit.