The chimney chimney has the form of a sealed channel, which is located in a vertical plane and serves to remove the combustion products formed in the firebox outside.
Varieties and materials
Fireplace pipes are of the following types:
monolithic or multilayer
decorative or the most simple
But in fact, it doesn't matter: what form, what material, prefabricated systems or not - nothing really matters. One thing is important - decent ventilation of the firebox. And based on these considerations, for the chimney, only that pipe is good, which ensures the room with the fireplace the absence of the smell of smoke and the ignition of firewood from the very first match.
If you are planning to install a fireplace with a chimney, then at least you should know a thing or two about the materials from which the chimneys are mounted.
These are chimneys that are resistant to relatively high temperatures. They have a high heat capacity and durability, but they cost a lot. A ceramic chimney is usually a three-layer structure with a ceramic inner tube (refractory), a heat insulator and a concrete shell. Heat insulators are non-combustible mineral wool, and in the concrete shell there are channels that provide a decrease in the temperature of the outer surface and additional heat removal.
A chimney made of steel is a round pipe, made of stainless steel or galvanized, with insulation and with an insulated circuit outside. The set of steel is quite simple to assemble and weighs very little. Metal pipes are becoming more and more fashionable today, and in order to connect a stove or fireplace to a chimney, they often use black steel products, because with them there will be no condensation at the fire source and the pipe does not corrode.
Ordinary metal cannot act as the main riser of the chimney. Liners and open connection components are most often enamelled steel section pipes with a metal thickness of at least 0.5 mm. This is due to their corrosion and acid resistance and the calculation for a temperature of 450C, and for a short time - at 750C. This is usually enough.
The cost of a stainless steel metal chimney will be higher, but its service life will also be long. In addition, this design is able to withstand a much higher temperature (up to 1200C).
If these are household heating sources, then the steel thickness is used in the range of 0.5-0.8 mm, sometimes 1 mm. At the same time, easy installation of the entire structure, its low weight and resistance to acids are of great importance.
The most acid-resistant steel pipes are grades of steel 304, 316 and 321. 430 is the same, but it is the most affordable in terms of price, and the weakest in terms of resistance to acid.
The highest chemical emission aggressiveness is obtained when liquid fuel is burned. It is worth mentioning here modular chimneys for metal fireplaces, which are single and double, insulated. They can be laid openly, without fear that the structure could catch fire or, even worse, a burn.
I must say that visually such pipes look quite aesthetically pleasing, do not require brickwork, do not require a foundation. The insulated double chimney is suitable for both indoor and outdoor installation.
A variant of combined insulated chimneys made of metal is also possible, when the inner part is acid-resistant stainless steel from 0.8 to 1 mm, and the outer part is thinner and enameled.
Sandwich stainless steel pipes require special attention.
This is, above all, durability, excellent traction due to the smoothness of the inner surface and minimal soot deposits.
At first glance, it is expensive, but it is unlikely that a brick structure, and even taking into account the foundation, mortar for masonry and payment for all work, will be cheaper.
This is a double-circuit chimney design with pipes of different diameters and the narrower one is inside the wider one. To prevent the pipes from touching, jumpers are provided.
The safest solution can be a fireplace device with an attached chimney. In this case, there will be no combustion products in the living room, even if the masonry becomes leaky. And such a smoke removal system is installed not necessarily simultaneously with the construction of the house itself, but at any convenient time.
About rear connection
In this case, a device in the form of a tee with an inspection channel and a condensate trap is connected to the chimney.
An externally placed pipe increases the area of a small room. The chimney for the fireplace is here led out through the wall near the heater directly into the street.
The traction force in it will also depend on the shape of the section of the chimney. The most aerodynamic pipes are circular. Square pipes are better than rectangular ones, and an oval chimney is completely rare, it is used only when a rectangular channel is made of bricks.
Chimney structures are mounted on top (installed on top of the fireplace and continuing it vertically), radical, that is, standing separately, when the vertical chimney channel with an offset location from the fireplace stands on a separate base, and wall, with a chimney channel passing inside the wall of the building.
Cases when the chimney may be more expensive than the fireplace itself:
if the firebox is simple, and the chimney system is of the most modern and reliable. For example, a ceramic chimney and an "economy" class fireplace insert
if the fireplace is a stove or fireplace, and the chimney is made of stainless steel, and even insulation is more than 10 meters high
if the old chimney channel is being converted into a modern heating system (liner or even a new chimney)
if they are trying to arrange a fireplace in a house where the chimney was not planned at all
if it is decided to build a free-standing modern chimney from the outside of the house
if it is decided to build a fireplace in a penthouse or on the top floor of a high-rise building
Design and dimensions
By its design, the chimney is a vertical channel installation in the wall, the height of which from the grate to the mouth is at least 5 meters. In this case, a slight vertical deviation is allowed. If the chimney is too high, the draft will be too high and the fuel will burn too quickly, and this will negatively affect the thermal efficiency of the fireplace.
In the case when a knee is provided in the chimney design, a tee is also installed, otherwise, in order to clean the chimney, it will have to be completely disassembled.
Each time the calculation of the design of the entire device will depend on a specific fireplace and a specific building, and therefore has individual parameters:
- pipe diameter and length;
- heights and sections of the box;
- fireplace power and manufacturer's instructions;
- the number and availability of components;
- mount methods for the entire device;
- thermal protection and fire-prevention cutting;
- the use of walkways associated with the ceiling and roof;
- elevation above the roof and the location of the head in relation to the ridge of the roof;
- the shape of the mouth in the channel and the location of the channels for smoke and ventilation in the common shaft;
- traction in the channel and some problematic elements of the entire structure, as well as the conditions of its operation.
When two in one is bad
Perhaps you decide to combine two fireplaces into one chimney.In theory, this can be done, but in practice such a solution will require compliance with many additional conditions:
- you will need to sheathe the chimney;
- choose the optimal chimney in terms of design and height;
- increase the section in the smoke channel;
- install plugs to completely block the smoke channel;
- when lighting fireplaces, follow the sequence;
- adjust the draft in one and the other fireplace, which will not be so easy to do.
A simultaneous firebox with several hearths and one chimney is always a problem:
- with chimney design;
- with roof guides;
- with connection options;
- with air exchange in the room;
- with economizer;
- with draft compensator and combustion support;
- with forced ventilation;
- with a side outlet, which can impair draft and increase the formation of condensation.
There will be so many questions that it will become clear that the best solution for two fireplaces would be this: one chimney for one fireplace, and for two fireplaces and chimneys you will need two.
The correct fixing for the chimney is very important. To fix the pipe, the outer contour must be crimped with a special clamp and fixed with rivets. After that, the clamp must be fixed on the ceiling with a special corner and fixing bolts. In this case, the bulk of the chimney weight will fall not on the fireplace insert, but on clamps and corners attached to the ceilings.
Even when the chimney for the fireplace is arranged in compliance with all the rules, a certain amount of water can still get into the chimney. Everything will depend on the section of the chimney and the size of the "skirt" that have an umbrella or deflector installed above the chimney.
How to choose
It is difficult to unequivocally answer the question of which chimney to choose. There is a main rule here: the choice of a chimney should in no case be based on its cost. In this case, this is not the main thing. You need to build on the following things:
- from the selected type of heating;
- on the type of unit that you have chosen;
- on how the chimney will be installed. If you invite a specialist for this - this is one thing, but if you rely on your own strength - quite another, then the work should be on your shoulder;
- much will depend on the intensity with which your heating system will be operated.
Calculate everything and give a correct assessment of your knowledge and experience in the chimney arrangement, and then make your choice.
In any case, the best chimney is the one that will allow your fireplace to function safely, efficiently and economically. And if a brick chimney is quite suitable for your unit, then you definitely do not need that ultra-modern and super-fashionable chimney, about which you have read such rave reviews on the Internet. It is clear that everyone will decide this issue at their own discretion, but you should always remember about the safe operation of your hearth, both for you and for everyone around you.
Correct laying and installation
The fact that the chimney must be correctly installed is even more important than installing the fireplace itself.
Errors in this case are unacceptable, because because of them, not only equipment can break down, but there can be a danger of carbon monoxide poisoning and even fire.
In order to do everything right, a wiring diagram must first be developed. For example, this:
Chimney requirements and options for its arrangement
Quite specific requirements are imposed on the chimney: to organize the removal of combustion products outside the premises.
This involves heating the structure to very high temperatures and contacting it with an aggressive environment (chemicals that were formed during combustion).
Another important issue is the formation of condensation as a result of temperature extremes.
Therefore, in order to connect a chimney, materials are needed that are strong enough, and depending on their choice, chimneys for a fireplace are divided into the following types:
- of steel;
- from ceramics;
- from glass.
Such a chimney is a brickwork. In terms of costs, this option is considered the most budgetary, but it does not differ in particular efficiency.
A steel chimney is a round pipe, stainless or galvanized, insulated and with an outer contour. The steel pipe is quite easy to assemble and weighs relatively little.
It is better to entrust the installation of such a structure to a professional with experience in such work. As far as the device of such a chimney is complicated, the thermal insulation is so excellent. Such chimneys can operate reliably for 30 years, or even longer.
This version of the chimney is considered the most expensive and difficult to install, but visually, the interior with this design looks very impressive. Glass chimneys are not afraid of corrosion, heating, or moisture, and this is their undoubted advantage.
5 most common mistakes
The most common mistakes include the following:
1. Incorrectly choose the chimney according to the configuration, which leads to heavy kindling of the fireplace, weak flame and smoke in the room due to weak draft.
2. If the chimney is not selected at a sufficient height, then sufficient draft will not be provided. The height of the pipe from the grate to the top on the roof should not be less than 5 meters. The higher the pipe, the stronger and the thrust. You can reduce the diameter and increase the height, then the volume of warm air will increase, and it will cool more slowly, which will have a positive effect on traction.
3. If the angle of deflection from the vertical exceeds the allowable, the thrust will also be poor, because the best thrust is in a straight vertical pipe. Any bend or tilt will worsen it, and the horizontal section will even more so. If a straight chimney does not work out in any way, then the displacement should be done using inclined elements, and the angle of inclination should not exceed 45.
4. Another mistake is the incorrect definition of the section. A decrease in the diameter of the chimney chimney below the permissible norm is not allowed, more is possible, but also not much.
5. Wrong choice of material for the chimney, and then it turns out that the properties of the selected material absolutely do not correspond to the conditions of its operation.
To build a chimney on the second floor means to mount it using a sealant either through a hole in the supporting wall, or through the balcony, if there is one. Here, a coaxial pipe is best suited for use as a chimney. It is double-circuit, that is, the inner circuit serves to remove waste substances, and the outer one for air intake, as in the diagram:
In the case of designing a chimney for a fireplace with its simultaneous connection with a kitchen stove, adhere to the optimal height and design of the chimney, with an increase in the cross-section and with the installation of several dampers so that access to smoke can be closed. However, according to experts, the fireplace chimney should not be connected to another heating device, including a stove.
How to remove soot
It will be safe and comfortable with a fireplace in the house only if there is good draft in the chimney. And this largely depends on his condition.
There are several cleaning methods for chimneys: there are folk ones that people have used for centuries, and modern ones - according to scientific developments. These methods include:
In the old days, chimneys were cleaned with aspen wood, which can generate heat in the furnace up to 1200C. Under this influence, the soot becomes loose and burns, and everything that remains of it flies out along with the smoke into the chimney.
Before cleaning with this method, you must be sure that such high temperatures will not harm your chimney, since it will be difficult to avoid destruction or fire if the chimney, for example, cracks.
Even in the old days, they used a different method of cleaning the chimney: they burned dried potato peelings, during the combustion of which substances that could loosen the soot were released, and then it was easily removed from the cleaning holes. But folk methods will not always be able to help, and in case of severe blockage, it is better to turn to chemistry.
Today in the stove shop you can find different cleaning agents for cleaning chimneys. It can be powder, tablets, liquid or special pellets, logs and briquettes, which are simply placed in the firebox (even with or without firewood) and burned. For more details on the use of each of the chemicals, everything is described in the instructions attached to them.
The most convenient of all the chemicals that clean the chimney are the cleaning briquettes. They heat the fireplace for about two hours, due to which the substances that hold the soot in the chimney are destroyed, and the remaining fines are carried out, like smoke, into the chimney.
If there was a large blockage in the pipe, it will fall down, and therefore, after servicing the chimney, it is necessary to revise the entire space of the chimney, for which there are special doors in it.
This method is the most effective and will cope with the most serious blockage that has occurred due to a strong narrowing of the lumen or due to the fact that some kind of debris has got into the pipe.
Chemistry here may not be able to change anything.
And operating such a fireplace is dangerous not only for health, but also for life - all deposits formed inside the chimney can catch fire, not only smoke can escape from the chimney, but also sparks, and even fire.
If the weather is dry, there is a high probability of fire, so if there is no draft, and the room began to fill with smoke, mechanical cleaning of the chimney will be required using special tools and devices.
Devices designed for mechanical cleaning of a chimney for a fireplace from soot and soot include special scrapers, brushes, brushes of different size and configuration, weights in the form of kernels to break through a dense blockage.
All this is on sale, but a lot can be done by yourself.
It may not be necessary to clean the chimney often, but if the soot build-up inside the chimney exceeds 2 mm, then it's time to work as a chimney sweep.