Re: attic fan and blown in insulation???
Does the attic fan blow out or in? How high above the existing insulation is its lowest part? If it blows out, you probably have nothing to worry about. If it blows in and it's less than about 12" (I guess) above, you may need to install a board to deflect the airflow away from the insulation.
Adding more insulation won't hurt. But you will eventually reach a point of diminishing returns where the cost of added insulation will exceed the energy savings. Your local utility company or building department can tell you what the minimum required and recommended insulation levels are.
The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.