Baffled chimney Cap
Q: Jason, whenever we have a really good fire in our fireplace, the whole house gets smokey. The flew is open so I’m not sure why. What should we do to fix this? I called my fireplace shop and they said to open a window a crack, that seems counter-intuitive since it is 5 degrees outside. I kind of like being warm.
A: I always get a kick out of people who say if your fireplace is smokey when you use it just open a window a little. Those people must not live in a cold climate because who wants to open a window when it is cold outside?! Tell them: “I live in Minnesota for crying out loud!”
Honestly, the best thing you can use to keep smoke where it belongs is some glass doors for the fireplace. They will keep the smoke and the sparks in and keep you from loosing quite so much interior heat to the combustion process and the suction of the chimney draft.
Another option is a directional wind may be blowing down at your chimney. Often winds can bounce off nearby trees and push wind currents down at your chimney. In this case, a baffled chimney cap will do the trick. My fathers Avalon wood stove had this problem and a baffled cap fixed the issue. See the image below of the baffled cap.
Remember to close that damper up good and tight when the fireplace is not in use. If you still have outside air entering even with the damper closed. Get a plug like a Chimney Balloon and it will keep the room more comfortable.