6 Different Types of Chimneys
If you’re building a house or even remodeling your home, choosing the type of chimney you want is a big deal.
Not only are you choosing something that’s going to heat up your house, but you want something that looks nice.
Do you want metal running up the side of your house? Or would you prefer the siding of the chimney to match the siding of your house? Or maybe you prefer the contrast that typical red brick gives.
Whatever the case may be, I’ll tell you what you need to know about the different types of chimneys.
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Chimneys work the Same
All chimneys basically work the same. They all work under the stack-effect principle.
All that means is that your house is a system of moving air. The cooler air is heavier than the warmer air. So the cool air comes in and pushes the hot air up and out of the house.
If you have a chimney, the hot air is pushed out through the chimney.
But chimneys aren’t just pushing out hot air. They release smoke, ash, and dangerous byproduct gases. Every fireplace needs a chimney to effectively remove all of those things.
There are four key factors that affect how efficient the stack effect is in your chimney. Chimney height, air pressure, the flue, and freedom from obstructions or damage. Issues with any of these will cause your chimney to malfunction.
That’s why, regardless of the type of chimney you have, it’s important to have your chimney regularly maintained and cleaned by a CSIA certified chimney professional.
When you think of chimneys, I’m betting that you think of masonry chimneys. I know I do. These are the typical ones that are built with materials like bricks, cement, mortar, blocks, or stone.
All the heat and smoke goes up through the chimney and releases out into the atmosphere. As the heat goes up, it’s not uncommon for the bricks to absorb the heat and helps to radiate to other rooms to keep them warm.
Masonry chimneys are really durable and can last as long as your house if you make sure that you give it the love and attention it deserves. In fact, the only thing left in many old houses is the chimneys.
Weaverville, NC, where I grew up, is where Zebulon Vance was born. They rebuilt the house in the 1960s around the original masonry fireplace from the 1790s! Also, my sister in-law’s grandparent’s house burned down sometime in the 1980s. The only thing that was left standing was the chimney and fireplace. I’ve read stories about chimneys being the only thing left standing after tornadoes or hurricanes.
But all that can’t go without saying that it’s easy for masonry chimneys to deteriorate too. Without proper care and regular inspections, you could miss a small crack in the crown of your chimney. That crack can contribute to leaks and additional cracks that will eventually speed up the deterioration of the masonry and flue.
We see these a lot. They can be either double- or triple-walled and are often enclosed within different types of casings since they aren’t the most aesthetically pleasing chimneys around.
They are usually encircled within the masonry, a sided frame, or even a fully wooden structure to help with the aesthetics.
In double-walled chimneys, you can find insulation between the walls. But with triple-walled chimneys, the layers have air between them to provide insulation and dissipate heat.
Most of the time, the metal chimneys that we install use bare stainless steel to give an industrial look to the chimney.
Also, metal chimneys are limited to 15 and 30-degree angles, so they aren’t as flexible as you might need.
And you might be limited to the type of metal depending on the fuel you use.
Prefabricated or Factory-Built Chimneys
A lot of newer homes that we work with have prefabricated or factory-built chimneys. These have the siding that matches your house.
Factory-built chimneys are exactly what they sound like. They’re manufactured and constructed in factories before being delivered to your house. The fireplace is a firebox that’s been fabricated with sheet metal.
What’s cool about these is that you can choose the metal that you want to be used for your chimney and fireplace.
But, factory-built fireplaces don’t fit all kinds of chimneys. So you need to make sure your factory-built fireplace works with your chimney. A good way to make this work is by buying the chimney and fireplace as a set.
Unfortunately, factory-built chimneys aren’t as durable as some other types and most likely won’t last a whole lifetime even with regular maintenance. The parts will eventually corrode and rust out.
To complicate things just a little bit more, there are four types of factory-built chimneys that you can choose from, such as air-cooled, double-walled, air-insulated, and combination chimneys.
The chimney industry is not very creative with naming its products. So you can probably guess that air-cooled chimneys have air flowing between multiple layers of metal. The purpose of the air is to circulate between the metal and dissipate all the heat. The air absorbs a lot of the heat that rises through the chimney.
Air-cooled chimneys are more cost-effective, but we don’t recommend them too often, especially if you live where it’s cold most of the year. Because severely cold weather can cause excessive condensation in the fireplace system, which eventually leads to premature corrosion of the metal.
You’ve probably heard these called mass-insulated chimneys. They are built using double layers of metal, usually stainless steel. The insulation material is placed between two metal layers so that the exchange of heat through the metal is reduced.
These chimneys are built in a way that looks like a smaller pipe wrapped in a blanket stuffed inside a larger pipe.
Most double-walled chimneys are lighter than brick chimneys, so they can be installed pretty easily and quickly.
Air-insulated chimneys are pretty similar to air-cooled chimneys. The big difference is that air-cooled chimneys move air around to cool heat. The air-insulated chimneys use air to insulate the pipe.
Air-insulated chimneys are built to minimize the air movement between the layers of metal or stainless steel. The air between the layers provides incredible insulation instead of dissipating or drawing away heat.
These chimneys are very durable, especially in extreme cold. They are known for improved longevity and great performance too. But with better performance comes an increased price. But I’d say it’s worth every dollar.
Can you guess what these chimneys are? I bet you can.
You probably guessed that they use a combination of the other chimneys. So combination chimneys use features from air-cooling, air-insulated, and/or double-walled chimneys.
The combination will allow you to play around with your chimney ideas to come up with an innovative design that looks good and is functional.
Fireplace Insert Chimneys
Fireplace insert chimneys are stoves that are inserted into an opening, usually inside a masonry fireplace. They fit perfectly inside the opening, so it doesn’t leak heat out the sides.
The insert is connected to the top of the chimney, usually with a metal liner. We recommend a stainless steel liner so that it can last much longer than the aluminum ones. Plus, stainless steel liners usually come with a lifetime warranty.
Most of the time, when we’re installing a new fireplace insert chimney, we are putting the insert into an already existing masonry fireplace and just connecting it to the flue to help flow outside.
If you have an open fireplace, this may be a good option for you if you’re wanting to have an enclosed look for your fireplace.
Freestanding Stove Chimneys
Freestanding stove chimneys are pretty versatile, so they can be used with either a masonry chimney or a prefabricated chimney. Just as the name suggests, they are freestanding stoves installed or inserted into a custom-built chimney.
Wood Burning Stove Chimneys
Wood burning stoves are interesting to me. We remove a lot of these but also install a lot. Wood burning stoves were very popular a long time ago and are making a comeback as people are switching from gas to wood.
A lot of times, these are also freestanding, but I needed to separate this from the freestanding stove because wood-burning stove chimneys cannot vent through the roof. They have to curve through the wall.
Talk to an Expert
I know this is a lot and might be hard to digest. Your chimney is a complex system and it’s always best to talk to experienced professionals, who know what they’re doing.
You should always hire certified chimney professionals to help with your chimney. At Patriot Chimney, we are members of the National Chimney Sweep Guild, and all of our technicians are CSIA certified. So you can trust your home and family with each of our experts.
When you’re hiring a chimney company, you should always ask the following questions before allowing them to come into your home:
- Can the company provide references?
- Does the company carry a valid business liability insurance policy?
- Does the company ensure that a certified chimney technician will be on the job?
If they guarantee all three of those, then you are in a good spot. The technicians don’t necessarily need to be certified by the CSIA, but I do recommend putting in a bit more due diligence before accepting a certification that’s not by the CSIA.
This is because certifications are a tricky thing, especially in an unlicensed industry like ours. Any company can craft a list of job-related questions and sell them as an exam and certify those who pass.
I recommend you take a few extra minutes in your research before making your hiring decision to learn more about the certification the company has. Here are a few tips to make sure the certification is reputable:
- Is the word “certified” just part of the business name or is it an earned designation?
- Is the certifying body a for-profit business or non-profit?
- Does the certification need to be maintained and renewed through continuing education as the industry evolves, or is it well enough to be certified through a one-time exam?
- Is the certifying body well-established or are they relatively new to the scene? New doesn’t mean “bad” but you should make sure the requirements for certification are more or at least equally stringent as those of more established certifications
- Is the mission statement of the certifying body focused on educating and protecting homeowners or is it more focused on making it easier to earn a certification?
- Does holding the certification require following a code of ethics?
If you can answer all of these questions, then I think it will be safe to allow the company in your home to work on your chimney. It doesn’t matter if you are in Roanoke, Lynchburg, Blacksburg, or some other city anywhere in the USA — if you have any questions about the safety of hiring a chimney company, please don’t hesitate to email me at firstname.lastname@example.org or call me at 540-225-2626. I’m happy to help!