If you enjoy lighting fires in your fireplace, you have to ensure that the smoke makes its way up and out the chimney. A very small amount of smoke getting into the room is not really a problem. Excessive smoke, however, is a big problem. In order to fix it, you have to first figure out what is causing it. The good news about excess smoke from a fire started in a fireplace is that it is usually only one of two things. Either the flue of the fireplace is not open or functioning properly, or there is a problem with the draft.
The damper in the flue opens and closes with a control to close off the fireplace from the outside and to open it up when you wish to start a fire. Before you start a fire, you should open up the damper fully so all of the smoke exits the chimney after it's burning. If, for whatever reason, the damper will not open or will only open partway, it needs to be repaired before a safe fire can be started. If the flue is clogged at any point from the top opening in the firebox to the exit at the top of the chimney, excessive smoke inside the house could be the result. Other things that can cause the flue to be blocked are bird nests, squirrels and other animals making a home out of your chimney. It can also be caused by a buildup of a substance called creosote, the tar-like residue that clings to surfaces when wood or coal is burned.
If there is a problem with the draft in your home, smoke could build up excessively inside every time you try to light a fire. Fireplaces rely on a current of air that both feeds the fire and channels it up and out through the chimney. When drafts are disrupted, there might be no air to push the smoke out, leading it to amass inside. Any change in the air pressure inside can help to disrupt the draft. Doors or windows that are opened and closed could unwittingly affect the ability of the smoke to exit through the chimney. When lighting a fire, the best thing to do is make sure all of the windows are closed. This will in part prevent any drastic changes made in the interior air pressure.
Newly insulated homes can also suddenly have draft problems. If air was accustomed to coming through small openings between window frames and walls or elsewhere that the insulation addressed, it could stifle the ability of smoke to escape through the chimney. Additionally, cold weather outside creates a downdraft that can keep the warm air and smoke from rising. Cold air is heavier than warm air, so this could also cause smoke to build up inside.
What to Do about It
To prevent downdrafts, a chimney cap can be installed. If too much air has built up in the house causing drafting issues with the fireplace, turn on fans in the bathroom and kitchen to help reduce some of the excess air. Make sure you close the windows and doors in all rooms before starting a fire. If not, there could be disrupted drafts as well. To solve the problem of creosote, have your chimney cleaned at least once per year. If needed, have the flue damper replaced or repaired.
Excessive smoke from a fireplace is not a comfortable occurrence. At worst it can be dangerous. If this happens in your home, it is either because there is a problem with the flue or there are draft issues inside. Through a process of trial and error, you can almost always determine the source of the problem and easily fix it.