Have you ever walked into your living room or den and noticed a musty smell coming from your fireplace? Have you ever noticed any cold drafts coming from your fireplace? A smelly chimney is unpleasant for anyone that is living in your home and can be a real embarrassment when you have company over. Furthermore, if the air coming into your home is also cold, you could be adding a lot of cost into keeping your home at the 
temperature that you want it at. These issues are inflated if you try to light a fire and smoke starts entering your home causing bad odors, eye irritation and smoke stains on your walls and furniture. All of the time these issues are caused by air pressure differences between your home and the outside. At Hale’s Chimney and Fireplace Solutions, we run across issues related to air pressure quite often. Our experienced chimney technicians can help you understand what is causing your air pressure issues and can find the easiest solution for fixing your issue.
Air Pressure
Although it’s difficult to notice, the air in your home is constantly in motion. Generally, lighter warm air will flow vertically towards the upper portions of your home while the cooler, denser air will rest in the lower sections of your home. There are a number of factors that can affect the airflow in your home, such as fireplace placement, the number of doors and windows in your home, or how windy it is outside, to name a few. However, a general understanding of your home’s air pressure and airflow and what affects it can help you solve issues that you are having with odor, draft, and smoke.
Air pressure is not the same throughout your entire home. In fact, depending on where you are in your home, air pressure may be positive or negative. This is because of something called the stack effect. The stack effect occurs when warm air moves vertically in your home and gets trapped in the upper portions of your home. Warmer air in the upper portions of your home slowly flows out of small cracks and holes in the roof and walls of your home. As the air gets pushed into your home, it is getting replaced by new air. Somewhere in your home is the Neutral Pressure Plane (NPP). This is an area in your home where the air pressure is neutral. Warm air above the NPP has a slightly higher pressure than the pressure outside of your home. Cooler air below the NPP has air pressure is slightly lower than the outside of your home, meaning that air from the outdoors will generally try to seep in through portions of your home below the NPP. Since newer homes tend to be airtight for energy efficiency reasons, this usually means that the best place for air to seep in is down your chimney and through the fireplace. As air moves through your chimney, it brings in odors and cold air with it. This is also the reason why smoke will blow into your home until your chimney gets warm enough to start drawing air out of your fireplace.
Wind Loading
Another issue with air pressure is caused by wind loading. When high winds strike the side of your home, it can cause pressure to be higher on the side of your home being struck by the wind. If a window is opened on the other side of your house, it will draw air outside, causing a backdraft in your fireplace.
Solutions to Air Pressure Issues
If you have issues with air pressure, there are a few things that you can do to remedy it. Before you start a fire, you can prime your chimney. Warming up your chimney before you start your fire will allow air to be drawn up your chimney, instead of into your home. You can warm up your chimney by rolling up a piece of newspaper, lighting it on fire, and then sticking up and holding it up your chimney to warm it up. You will know when your chimney is warm because you will be able to feel the airflow change direction.
You can also prevent air coming into your home by installing a Lock-Top damper. A Lock-Top damper is a stainless steel and aluminum damper that seals your chimney at the opening. We here at Hale’s Chimney and Fireplace Solutions like Lock-Top dampers because they are made with high-quality materials and come with a factory lifetime guarantee. Lock-Top dampers are designed with a silicone seal around the opening that seals air-tight, preventing any airflow in and out of your home.
You don’t have to live with a smelly, cold fireplace anymore. Call Hale’s Chimney Chimney and Fireplace Solutions at 972-563-6851 or contact us online to discuss how we can remedy issues within your home today. We look forward to hearing from you and from our home to yours, have a wonderful holiday season!