How to Prevent Smoke from Entering Your Room

A wood stove can offer vital warmth during the cold winter months and serve as an excellent addition to any living room. But if it begins to billow out smoke into your home, it can become bothersome and even dangerous in large enough quantities. If smoke is entering your house from your wood fireplace, it's usually due to something called the stack effect.

The stack effect occurs when the cold air from your chimney, which is more dense, encounters the warm, lighter air of your fire box, creating pressure which pushes the smoke into your room. So, how do you stop this from taking place and prevent excess smoke?

How to Prevent Smoke from Entering Your Room from a Wood Stove

Step #1: Wait Before Adding Larger Logs

When you first begin starting your fire, make sure to wait a bit longer before moving on from the kindling stage. This will be shortly after you light your firestarter, when you are adding small slivers of wood to get the fire going.

Step #2: Give the Heat Time to Spread

As the kindling burns, make sure to give the heat enough time to warm up the stove and chimney. This may take up to 15 minutes. As the air within the stove and chimney heat up, they will reduce the pressure of the cold air that has built up in and above your fireplace.

Step #3: Let Your Fireplace Draft Air

The warm air should begin to draft as the fireplace heats up, establishing proper airflow. This means that the smoke should begin to flow up the chimney and outside of your home, as opposed to into your room. If the smoke is still coming into the room, you can test the draft to make sure that the flow is beginning to move in the proper direction. A test can also highlight what parts of your fireplace are causing the issue, which can make fixing the problem far more simple.

Step #4: Test the Draft

To check that the draft is moving in the correct manner, you can conduct a simple experiment known as the newspaper test. The basic function of this test is to burn a piece of paper in the fireplace to see which direction the air is moving. Refer to the section below labeled “How to Test if the Fireplace Draft is Moving Correctly” for complete instructions on how to do this test.

Step #5: Once Air is Flowing Properly, You Can Add Wood

Once your fireplace is completely warmed up and the draft is established, smoke should begin to flow the proper direction. Once smoke is no longer entering the room, you can open the door to your wood fireplace and add more wood as needed.

How to Test if the Fireplace Draft is Moving Correctly

You can test the draft of your fireplace’s chimney by conducting the newspaper test. The newspaper test involves lighting a newspaper and holding it inside of the fireplace or woodstove as high as you can. If the draft is moving correctly, the paper will have no trouble burning. A good draft may even produce a sound, with the chimney and stove pipe making a “roaring” noise as they both warm up. If the paper goes out, the chimney draft may not be moving correctly. You could have a blockage, which will need to be cleared once your chimney cools down.

If the blockage is higher up in your chimney, do not attempt to clean it out on your own. This can be difficult and dangerous without the right tools; instead, consult a professional chimney sweep. They can assist you with any higher blockages, and inspect your fireplace for other potential issues.

Is Smoke from a Fireplace Harmful?

Yes, smoke from your fireplace can be harmful if inhaled. The smoke from burning wood is made up of fine particulate matter and various gasses. This combination can enter the lungs and eyes, causing difficulty breathing, irritation, and illnesses like bronchitis. If a person is at risk of heart attacks or stroke, fine particles can trigger these and other conditions.

Asthma Sufferers: The fine particles present in wood smoke can irritate the lungs of those with asthma, causing an asthma attack. Other lung diseases, like COPD, are also aggravated by inhalation of wood smoke.

Children: Because their respiratory systems are still developing, young children are particularly sensitive to wood smoke. They also intake more oxygen on average than adults, so are likely to breathe in the smoke more quickly.

Elderly Residents: Older adults tend to have more chronic lung or heart issues than younger demographics, and are therefore more likely to suffer complications due to wood smoke.

Other Ways to Prevent Smoke from Entering the Room

Use the Correct Fuel: Excess smoke can be caused by using the wrong wood; if your wood is wet, unseasoned, or treated with chemicals, you shouldn't burn it. This is especially true with wood that has been contaminated in some way. If your wood has paint, galvanized nails, or some form of chemical treatment, the smoke it produces could be hazardous.

Keep Your Fireplace Clean: A regularly cleaned and inspected fireplace will almost never produce excess smoke or an incorrect draft flow, so make sure to keep your fireplace clean. All manner of obstructions can block the air flow within your fireplace and chimney, including the build-up of creosote, debris that has fallen from outside the chimney, and nests built by animals.

Check the Height of Your Chimney: Sometimes, the issue is with your chimney. If your chimney isn’t the right height, it may not be equipped to handle a wood fireplace. Make sure that your chimney is at least ten to twelve feet high, projecting out from your roof at a length of three feet. As a rule of thumb, the chimney should be two feet taller than any object or structure around it. This includes surrounding trees and the roof of your home.