Help With Inline Fan

i currently have my 4in inline fan pulling cold air from attic is there any danger
with pulling air from a attic the attic is lined with fiber glass instalation
i cleared room and layed a bunch of carpet down

The question is somewhat confusing (carpet?), but seems to be in regards to "cold-air" entering your grow space. Don't blow the air directly on the plants, IE point the exhaust at a wall, ceiling, floor and watch your humidity/temperature over 24 hours. If your humidity or temperature doesn't get "too" low your good. (you can define too low however you want but looks like you don't want anything below 65f or about 25% rel. hum.). If you are worried about the insulation getting sucked in, just put some piece of cloth or screen over the intake (<$1 at HD/WM - think screen door plastic/metal mesh).

GL,
z