From the outside, your chimney may just look like a straight-sided, hollow stack of bricks. In reality, though, there’s a bit more to it than that. In fact, your chimney is a structure that contains a number of parts, all of which work together to perform an important job – venting smoke and gases from your fireplace safely out of your home.
Are Flues Different Than Chimneys?
Sometimes people conflate the two, but chimneys and flues are in fact different – both in function and structure. In both categories, they complement one another.
- A chimney is the entire structure that serves as a passage for heat, smoke, and gases to escape your fireplace. A chimney includes component parts such as the smoke shelf, damper, chimney cap, and flue.
- A flue is the internal passageway inside the chimney that carries the smoke and gases upward and out. The flue is simpler than the chimney proper, and is often aided and protected by a smooth, heat-resistant flue liner made of clay or ceramic tiles or stainless steel.
Put simply, the chimney is the venting system, while the flue is the internal duct or passage within the chimney. One chimney can have more than one flue, if more than one appliance or system is connected to it.
If you have a fireplace, it’s important that the chimney be inspected each year. If your home is new to you, it’s best to have an inspection done quickly upon moving in. This helps ensure that your flue liner is free of cracks, chipping, or gaps that can cause hazardous leaking or subpar performance – and that there isn’t a build-up of creosote in your system.
How Do My Chimney & Fireplace Work?
Your chimney and fireplace need each other to function. When you light a fire in the fireplace’s firebox, the heat produced causes the air in the firebox to rise. This natural upward flow of air creates a draft that pulls in oxygen to fuel the fire. As the air moves up, it draws smoke and gases into the chimney and out through the chimney stack.
Here’s a little more about how that journey takes place:
- The firebox is where you actually build your fire, the chamber in your fireplace that opens out into the room. Whether you have a gas stove or insert, a traditional open hearth, or a wood or pellet burning insert, the purpose of the firebox is the same: to provide the space to burn fuel and generate heat. You want to retain that heat to warm your space, but the byproducts need to be vented out.
- Above the firebox (either immediately above or higher, if you have a top sealing one) is your damper. This movable plate helps regulate airflow through the chimney when you open or close it. An open damper lets air flow freely up the flue, while a fully closed one seals off the chimney when the fireplace isn’t being used. The amount of air let in by the damper affects how well your fire burns.
- The smoke shelf and smoke chamber then help funnel smoke and gases into the flue. The smoke shelf also helps protect against downdrafts and keeps debris from falling into your firebox.
- By now you have a pretty clear idea of what a flue is. This is the pathway the combustion byproducts will now follow. Flues are often lined to help your chimney withstand the high temperatures and corrosiveness of the combustion gases. This is a tough job, so flue liners can deteriorate over time. They should be swept and inspected regularly as an essential safety and system maintenance process.
- The chimney stack is the part of your chimney that extends from the roof of the house. Part of the stack is the chimney crown, a concrete or stone slab that protects the chimney from the elements, especially moisture. At the very top is a chimney cap, which serves to keep debris, wildlife, and precipitation out of the chimney flue.
Each element of the chimney system plays an important role, helping to keep the fire going and keep you safe as you enjoy a fire’s warming glow.
Invest in Regular Maintenance & Inspections With Us
To keep things running as they should, regular chimney and fireplace maintenance is crucial. Chimneys are strong, made of hardy, durable materials and engineered to last…but if problems arise and go undetected, the efficiency and safety of your system can take a hit. As with most things, early intervention can save you – in this case the savings translate to money, hassle, and system integrity.
Having our friendly professionals inspect and sweep your chimney will help keep your chimney flue in good repair and obstruction-free. Call today or reach out to us online to get scheduled. We’d love to work with you soon.
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