Expert: James Ball - 11/15/2008

Question
We recently purchased a brand new home and just tried out our fireplace for
the first time.  When we lit the fire most of the smoke from the fire came into
the home from the opening from the fireplace.  We have tried adjusting the
venting, opening windows (cracking a few), lifting the harth (the rack that the
wood rests on) and nothing is working.  Do you have any suggestions on what
we can try next to prevent this from happening.  We are at the point of not
using our fireplace in our brand new home.  Any suggestions will help.  
Thank you very much.

Answer
Hello Katzy, What is happening is you are getting Negative Pressure in your home, your house is a better chimney than your chimney and it will pull the air from the path of least resistance from your home and in most cases it will pull that air down a fireplace and with it smoke/odor the house needs make up air. Maybe open a window  all the way in that room? Maybe extend the flue to make it taller it might help the draft.
you will have to try several different things to see if you can get it to work. try to find out where the air is getting out of your home, see if Mechanical draft is affecting it( kitchen /bathroom exhaust fans), try to pre heat the flue with a hair dryer blowing up the chimney to help get the draft  going, Furnace returns located to close to the fireplace...etc?
if it is 30 degrees out side and 70 degrees inside the air in the house will rise and pull air down the chimney, once you have a fire going in the chimney and the air in the chimney is 100 degrees it will reverse the air and it will draw air from the house to feed the fireplace
hope this helped
James