FPX blower external/internal wall and positive air

[BZN]

We live in Montana and our blower is mounted INSIDE. So how does the fireplace create positive air flow if this is the case? I thought it needed to pull outside air in to create positive air and push hot air throughout the house.
As is, the great room gets super hot and little hot air get to the rest.

Also, why can't I mount it outside? Yea, we get some cold air, but wouldn't a damper or some such thing control that?

 

[sticks]

There is a damper flap that does control a lot of that air infiltration. If it is in the same room you don’t receive any of the benefits of the positive air flow. We have put some in basements which helps with spreading the heated air