Originally Posted by MarkeMark
Sorry to have bothered you Bassdogs.
Not bothered at all. Its on of the thing that the forum doesn't do a good j0b explaining. The "search" feature is like going to the library or doing a google search to research an issue and gain the knowledge of other forum members both present and past. That allows the poster to refine their questions and focus in on specific things that will help them make a decision.
Now back to my original comment. Each and every thing said so far on this thread has been posted many times before. As they say in the "climate change" world, use of roof vent covers is established science. In this case its true. In the case of climate change, its false.