Having cold air come down your chimney is a common problem many homeowners face during the winter months. Not only can it make your house feel drafty and cold, but it also reduces the efficiency of your heating system as warm air escapes out the chimney. Luckily, there are several effective solutions you can implement to prevent cold downdrafts and improve the performance of your chimney.
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What Causes Cold Air Down the Chimney?
There are a few main reasons why you may be experiencing cold air coming down your chimney:
- Poor chimney design – Some chimneys are built too short or too wide, which allows cold outdoor air to drop down easily. Proper chimney height creates draft that pulls air up and out.
- Lack of insulation – If your chimney lacks adequate insulation, it allows outdoor temperatures to cool the inner flue tiles. This turns the chimney into a giant cooling system drawing in cold air.
- Improper chimney cap – Corroded, cracked, or poorly fitting chimney caps can allow rain, snow and cold air to enter the chimney and travel downward.
- Nearby trees/structures – Tall trees or buildings located too close to the chimney can cause downdrafts.
- Tightly sealed house – Tight insulation and sealed windows/doors create negative pressure in the house that sucks air down the chimney.
Identifying the specific factors causing cold air in your chimney is important in order to select the proper solution.
Short-Term Solutions for Cold Air Down Chimney
If you need a quick fix for downdraft issues, try these short-term solutions:
Close the Damper
If cold air is coming down an unused fireplace, make sure to keep the fireplace damper tightly sealed when not in use. This prevents outdoor air from entering the chimney. Install storm collars around dampers for a tighter seal.
Use a Chimney Balloon
Chimney balloons are inflatable pillows made from heavy plastic that fit inside the flue liner. When inflated, they completely seal the chimney to prevent downdrafts. Use them to temporarily seal unused chimneys or during seasons when the fireplace is not in use.
Plug the Flue with Insulation
For very short term use, you can loosely plug the flue with fiberglass insulation. This blocks the pathway for cold air but should not be left in place for more than a few days.
Have Your Chimney Swept
Build up of creosote and other debris inside the chimney can constrict airflow and worsen cold air problems. A professional chimney sweep can clean out the flue to improve draft efficiency.
Long-Term Solutions for Preventing Cold Air Down Chimney
For a permanent fix to cold draft issues, consider these long-term solutions:
Install a Chimney Cap
Adding a chimney cap on top of the flue is one of the most effective ways to prevent downdrafts. Quality chimney caps feature screens to keep out debris while still allowing smoke to vent. Look for high quality stainless steel or copper caps. Make sure it fits properly with no gaps or cracks.
Extend Chimney Height
If your chimney is too short, extending it to proper height can improve draft issues. As a rule of thumb, chimneys should extend at least 3 feet above the highest point of your roof and clear nearby obstructions by at least 2 feet.
Insulate the Chimney
For severely cold chimneys, professional installation of insulation inside the chimney can help regulate temperatures. Fiberglass liners, Vermiculite or blown-in insulation helps prevent cold air conductive down the flue tiles.
Have Chimney Relined
If your flue has deteriorated, cracked, or is the improper size, having it professionally relined can restore proper draft performance. Relining involves installing new corrosion-resistant flue tiles that seal off air leaks.
Install Glass Doors
Attractive glass doors seal off the front of the fireplace when not in use. This minimizes cold air coming down the chimney while also preventing heated room air from escaping up the flue. Use high-quality tempered glass doors.
Remove Nearby Trees/Buildings
If nearby trees or structures are located too close, they can cause turbulence and downdrafts. Trimming back encroaching tree branches or cutting trees down altogether may be required. Also relocate woodpiles, sheds, or other buildings away from the chimney.
When to Call a Professional
While some chimney troubles can be DIY fixes, more complex downdraft issues often require a professional chimney sweep. They have the skills, equipment and access to fully diagnose and repair chimney problems. Call a pro for:
- Chimney crown repair
- Adding chimney insulation
- Chimney relining
- Chimney extensions/alterations
- Capped chimney installations
- Advanced chimney troubleshooting
A chimney professional can assess your roofscape and diagnose the real cause of downdrafts. With their repairs, your chimney can once again function safely and effectively.
Conclusion
Dealing with annoying and chilling downdrafts is an unnecessary burden during winter. Thankfully, resolving cold air coming down your chimney is usually a fairly straightforward process. Following proper chimney maintenance practices year-round is key to preventing problems.
Implement temporary fixes like chimney plugs or caps to get through the season when needed. For the optimal long-term solution, have your chimney inspected and improper designs or deteriorated materials addressed. With a little diligence, you can stop cold chimney downdrafts in their tracks and enjoy steady warmth from your fireplace or heating system.