Know Your Chimney’s Anatomy
By mainechimne63644266, Apr 28 2020 08:09PM
Your chimney may be the biggest system in your home besides the central air and heating unit and there’s a lot that can go wrong with it. Because it’s so big and can cause big problems for your home, it’s important to understand just what makes up the chimney system.
Chimney Cap – The chimney cap is the roof of the chimney system. It keeps water, animals, wind, and weather out. The cap is necessary to prevent chimney water damage and animal intrusion. It is often made of copper or stainless steel.
Chimney Crown- The chimney crown can be considered the roof of your chimney. It caps off the top end of your chimney, only leaving the flue open. The chimney crown protects the chimney from weather-related deterioration and damage. To avoid expensive moisture damage in the rest of your chimney, it’s important that the chimney crown be in good repair and free of cracks or openings.
Flue – The flue is the interior vent by which smoke and gases travel out of the home. The surface of the flue should be covered with a liner that keeps heat and corrosive chemicals from damaging or moving through the masonry and gives it a seamless, smooth surface for optimum airflow.
Smoke Chamber – The space above the firebox is called the smoke chamber—so named because this is where the particles and gases mingle with the heat to rise up the chimney. It is shaped like an inverted funnel to direct smoke upward and into the flue. Beneath the smoke chamber, there is a shelf (called the smoke shelf) designed to prevent smoke from falling back into the firebox and into the home. The walls of the smoke chamber should be at certain angles and smooth.
Chimney Damper- A chimney damper is what seals off your chimney flue when it is not in use. Generally, chimney dampers are installed just above the fireplace and are used to keep the air in your home from escaping out of the chimney. This helps conserve energy and reduce heating and cooling bills. If you have no chimney cap installed, your chimney damper is also your main line of defense from keeping critters and birds from entering your home through the chimney flue. If you close the damper when the fireplace is not in use, it’s extremely important to remember to reopen it once you start a fire, otherwise smoke and dangerous carbon monoxide can back up in your home and cause some serious health hazards.
Smoke Shelf- The smoke shelf is located where the smoke chamber intersects the firebox. Its main purpose is to collect rain water and small amounts of debris that have fallen into the chimney flue. It is used to help transition large billows of smoke from the fireplace into the narrower space of your chimney flue. The smoke shelf also assists with preventing downdrafts to ensure smoke won’t back up in your living space.
Firebox – The space where the fire sits and burns is called the firebox. It endures the highest temperatures for the longest periods but receives the least attention. The firebox is constructed of firebricks and refractory mortar.
Hearth – The hearth is the floor of the firebox which usually extends from the back of the fireplace out into the room a bit and is made of a particular firebrick and refractory mortar that protects against heat transfer from the fire.
As you can see, chimneys are complex systems that contain many different components. Your annual chimney inspection can make sure that each of these areas of your chimney are functioning as they should and are not in need of repair or replacement. Call Maine Chimney Sweep if you are due for your annual inspection or chimney cleaning. 618.234.6364