When a chimney system works perfectly, there is virtually never a draft. Achieving successful chimney venting requires more care than ever, since houses are sealed more tightly than in previous times. Homeowners often put up with drafty fireplaces, not knowing that it’s not supposed to be the norm.
A perfect venting system begins at the point of construction and includes the following components:
- The chimney is built in such a way that the flue lining has a straight path from the fireplace or wood stove to the chimney, with no offsets, since flow resistance is created by changes in direction.
- The chimney runs inside the walls. This is important because flue gases can stay warm until they are expelled. If the chimney is on the outside wall, the chimney can easily become filled with a column of cold air that pushes down toward the fireplace and causes a draft until the frigid air is replaced with warm air.
- The chimney is the highest part of the building envelope and its height clears all obstacles to wind flow, which results in the ability to produce a stable draft.
- There is a chimney cap or rain cap on the chimney. This is important because it prevents the chimney system from being vulnerable to strong wind pressures.
- The house itself needs to have a balanced ventilation system. Exhaust-only ventilation systems in a tightly sealed house work against the proper operation of a chimney. In addition, large exhaust fans can cause a house to become overly depressurized.
- The chimney flue is the proper size for the appliance. It’s important to have the help of a professional since proper drafting requires the right fit. Eliminating leakage around the flue connection is also important, since the system can be more vulnerable to adverse wind pressures if there is a leak.
- The chimney flue is properly insulated, which further ensures that the air can stay warm and more quickly flow up the flue.
- The stove or fireplace insert is certified by the Environmental Protection Agency as an appliance with low emissions or has characteristics which prevent the appliance from smoldering, which is far more likely to cause smoke spillage.
- The appliance is properly operated and maintained. Even if the chimney system is optimal, improper usage can cause a disruption in effective venting.
- Have your chimney cleaned annually or as needed, since a buildup of creosote can create chimney blockage.
If you are going to have the benefit of an ideal chimney system, it just makes sense to use optimal firewood. The following are some firewood tips:
- Always burn firewood that is seasoned, which means that it has low moisture content. When logs are first cut, they can contain as much as 80% moisture. The wood should be properly stacked and protected from rainwater while at the same time having the benefit of air, and it will take usually between six to nine months to become seasoned.
- An excellent option, if seasoned firewood is not available, is to burn high-density compressed sawdust logs.
A fireplace is the perfect addition to any home, and it’s even more of a pleasure when it operates properly. Contact our chimney professionals if your chimney doesn’t operate the way it should or if it’s time for your annual inspection and cleaning.
Northeastern Chimney, Inc.
formerly Nayaug Chimney Services, LLC
37 Cody Street, West Hartford, CT 06110