I know there is a lot of yea & nea's on the OAK. Here is my idea.. If I pre-heat the OA and let it out in the house and let the stove pull from the house then it would cure a few concerns. OA cold. O2 in the house to help with back draft. I have a few ideas on how to pre-heat with a little engeneering. What do you all think? Is it worth it? My house is semi tight. I have a HS Eq. in a 2000 sqft house.