Drolet insert -- fresh air intake

I have this insert and I never did anything with the fresh air intake other than take the cover off.

http://www.menards.com/main/store/2...ilders/Install_Instruct/45221A_12-09-2014.pdf

I really can't get outside air from where the insert is located, but I could feasibly get some air from my unheated basement, (which is a "little" drafty). My question is, would it be better to draw from the basement rather than have nothing at all?

Insert works fine but just want to do what I can to improve performance.

Thanks much.

actually, come to think of it, I could run a pipe up to my attic which has plenty of fresh air -- many soffit vents and a ridge vent so that would be ok right?