Why didn't you just duct fresh air into the room? I put a dryer vent on the outside (under deck) and use it to draw fresh air in thru 4-in ducting down to a floor register in the bottom kick plate of the stairs. Out of the way but easy to access. Open it in winter when wood stove is running... close it in summer. No motors. No warranty's. No repairs. No replacements. I also have ICF's (for my basement) and am amazed that you don't have a concrete board barrier between the insert opening and the ICF forms! They don't 'burn' easily but DO 'melt' down and outgas until the temps are high enough to cause open flame. You're the man, I know you KNOW how do do things so hoping you'll elaborate so I understand more! (I iz a jack-leg... but still try to learn!)