I am not sure why it would be a fire risk if the fireplace normally has real fire in it with no problem.
The fire place is on the end unit not facing the house next to us. My concern would be the venting not working and coming back in the house so the sealing of the flue seems to be the main point.
Nope; I just opened the flue, stuck the hose a few inches up there, let the flue drop back down to hold the hose in place, and that was that.
1/2 the surface area of the flue opening was uncovered, and it was still just perfect. The fan is so strong that you can actually feel a strong draft as it sucks air into the room, and it blows the smoke right up the chimney, with zero smell.
Prior to that, I was sticking the hose about 8 inches out of a window, and a fair amount of smoke smell would blow back in to the room. Probably from being sucked back in by the vacuum caused from the same fan that was blowing the smoke out, lol.
No pic of where it enters the flue, though, sorry, and Iâve had to move it from the spot; wifey wanted the room, gggrrr.