If you are a little esthete and romantic, then the fireplace is exactly what you need. The fireplace has a long history and its appearance is lost in the mists of time. It is only known that the fireplace originates from a simple open hearth. Translated from Latin, the word “fireplace” means “hearth.”
Construction and principle of operation.
By its design, the fireplace is a simplified version of the stove. One of the main differences is the method of heat transfer. The furnace uses the heat of combustion of fuel more fully, as it has a closed firebox, a massive structure and a developed convective system. During the operation of the furnace, warm air rises from its walls to the ceiling, cools near the outer walls and windows, and then, descending to the floor, heats the entire area of \u200b\u200bthe room.
This method of heat transfer is commonly called convection (heat transfer with the help of air flow). Among other things, the thick and massive walls of the furnace keep heat for a long time. As a rule, the design of the fireplace provides for an open firebox with a large combustion opening and a straight, without smoke circulation, smoke channel.
Hot flue gases are directly discharged into the chimney. In addition, the masonry of the fireplace is not very massive, in comparison with the stove. The open flame of the fireplace can heat the air in the room very quickly, but as soon as the firewood burns out, it stops heating almost immediately. The fireplace is not able to store heat like a stove.
Thanks to this feature, the fireplace is able to prevent the formation of dampness, as it perfectly ventilates the room. In the fireplace, the amount of air supplied to the wood is much greater than is necessary for the normal combustion process, so the temperature of the flue gases is low. The presence of poor draft in the fireplace does not allow the installation of chimneys.
The fireplace chimney has a straight design, which helps to extract a large amount of heat with hot flue gases, and works like a pump (for blowing). The heat from the fireplace is felt only by the person sitting directly in front of it – this is heat from burning firewood, transmitted by thermal radiation. Only a negligible part of the heat is transferred to its walls, so it does not retain heat well.
It should be noted that using a fireplace as the main heating device is extremely inappropriate for our climate zone.
The fireplace today, first of all, performs a decorative function. Its main task is to create a cozy atmosphere and aesthetic beauty, which is also important in our turbulent and stressful time. The enchanting flames of burning firewood captivate the eye, soothe, create a feeling of physical and spiritual comfort.
It is no coincidence that in America, where a fireplace is traditional, but far from affordable for everyone, videodiscs with the sound and image of a fire burning in a fireplace have recently become very popular. Americans put on such a disk, turn on the heaters, turn off the lights, light candles and try to relax, relieve stress or just chat in a calm atmosphere with close friends and family.
Currently, the fireplace is increasingly used to decorate homes, to create a unique interior, as well as an independent source of heat to supplement central heating. In warm southern regions, a fireplace is mainly installed to provide a favorable indoor climate. In northern cold areas where central heating can’t always keep up with the cold, a fireplace can serve as an excellent supplementary heating appliance.
Optimal placement of the fireplace. In order for the fireplace not only to fit perfectly into the interior of the room, but also to give the maximum thermal effect, its location in the room must be carefully considered. The room in which the fireplace is supposed to be placed must be large enough. It is highly undesirable to install fireplaces in a room with an area of less than 20 m2, since a large amount of air is required to maintain combustion in the fireplace, which cannot be provided by such a small space.
When choosing a place to install a fireplace, it is necessary to take into account the circulation of air flows inside the building. The presence of drafts can cause interruptions in draft in the fireplace, which can cause it to smoke. That is why fireplaces are not recommended to be placed in front of windows and doorways, in the way of air movement.
In addition, the place where it is planned to install a fireplace should be selected taking into account fire safety requirements. If all of the above conditions are taken into account, then you can choose one of the most practical and proven options for placing a fireplace, taking into account the compositional solution for this living space. As a rule, a fireplace can be placed in a wall, built near it, mounted in the middle of a room or in a corner, etc.
All fireplaces currently in use can be conditionally divided into three main types: open, semi-open and closed. Installation of open fireplaces is allowed only in the middle of large rooms or outdoors (in the summer kitchen, on the terrace or in the garden). An open free-standing fireplace-grill in the recreation area will look great. It can be equipped with racks for pots and skewers, have a grill for cooking meat. Such a fireplace-grill can be effectively attached to the wall. It can be of almost any shape – rectangular, square and even round. Such fireplaces are quite simple to manufacture and efficient in operation, heat spreads from them in all directions, while occupying a significant area. If such a fireplace is placed indoors, then it is necessary to hang a chimney and a smoke box above it.
These fireplaces can also be installed on special supports or hung on chains or springs. The design of semi-open fireplaces is not related to the design of the walls, so they can be placed both against the wall and in the corner of the room. In semi-open fireplaces, chimneys are built either inside the wall or attached to it. Such a fireplace takes up more space, but it can be built in almost any, even an already inhabited house. Closed-type fireplaces, together with chimneys, are mounted in a solid wall or in the corner of a room. This design of the fireplace allows you to significantly save the usable space of the room, which is especially relevant for small rooms.
The rear wall of the firebox of a closed-type fireplace is located in the plane of the wall, and its front part protrudes into the room. In addition, it is allowed to install a fireplace in the outer wall of the building, provided that its thickness is more than 51 cm (2 bricks). It is possible to equip fireplaces of this type exclusively in houses under construction, performing their installation simultaneously with the laying of walls. One of the very advantageous designs is the combination of a fireplace with a stove. Such a fireplace will not only be an original element of the interior, but will also allow you to quickly heat the room and retain heat for a long time. In this case, the stove and fireplace will have their own fireboxes and one common chimney. This design will significantly save the usable area of the room and building materials, and besides this, the so-called “fireplace oven” can be used for heating and cooking.
In most cases, a fireplace is installed in the dining room or living room, but sometimes this room can combine the function of a dining room, a living room, a library, and a bedroom. In a multifunctional room, using a fireplace, you can easily create a cozy corner for receiving guests, relaxing and pleasant communication. If the room has the shape of an elongated rectangle, then you should not place the fireplace against a large wall or in the middle of it. It will be much more comfortable and practical to place it in the back of the room near the end wall. It can also be combined with a kitchen stove or oven. In some cases, in such fireplaces they arrange a second firebox that goes into an adjacent room.
If you are planning a room in the style of a traditional English house, then it is best to place the fireplace against the largest wall and arrange a kind of seating area in front of the fireplace. For small spaces, corner fireplaces will be appropriate. This fireplace is the so-called attached, and can simultaneously partially heat 3 adjacent rooms at once. Such fireplaces can be used as a partition dividing a room into two zones with different functional purposes. In the same capacity, you can use fireplaces located in the middle of the room.
Varieties of fireplaces according to the method of heat transfer. Throughout history, the design of fireplaces has constantly evolved, modified and improved. The change in the design of the fireplace, in the first place, was aimed at obtaining the maximum amount of heat with minimal fuel consumption. Basically, the savings effect is achieved due to ingenious exhaust and supply air systems, the implementation of special convection stone inserts and changes in the design of the furnace itself.
Currently, there are three types of fireplaces according to the type of thermal radiation: with one-, two- and three-sided heat radiation.
Fireplaces with one-sided heat radiation are mostly open on one side only. Fireplaces of this type are located against the wall. Structurally, the side walls of these fireplaces are deployed in such a way as to ensure maximum reflection of heat into the room. The rear wall of the firebox has a slope in the upper part, which also provides an increase in the concentration of thermal radiation from the fireplace towards the room.
Fireplaces with double-sided heat radiation are less efficient in terms of heat transfer compared to fireplaces with one-sided radiation, since they do not have one of the reflective surfaces. In addition, this type of fireplace requires more air to support the combustion process, and, consequently, more hot air goes into the chimney. Fireplaces with three-sided radiation have even lower thermal efficiency, since in their design they have only one surface that reflects heat. Basically, this type of fireplaces is built to create a favorable microclimate in the room and for interior decoration. As a rule, fireplaces with three-way radiation are built in the middle of the room.
Varieties of fireplaces according to the method of heating. Depending on the method of heating the room, fireplaces with convective heating and pure radiation are distinguished. Fireplaces with pure radiation heat the room by reflecting thermal energy from the walls of the furnace into the room space. Strengthening the effect of radiation is achieved by tilting the side and rear walls. Fireplaces with convective heating in their design have special thermal chambers made in the form of cavities in the fireplace body. Cool air enters these cavities, which, heating up from the walls of the firebox, enters the room in a heated state.
During the construction of such fireplaces for the installation of fuel chambers, the back and side walls of the fireplaces are made in the form of a double structure. Varieties of fireplaces by functional purpose. Depending on the functional purpose, decorative, outdoor, combined and heating fireplaces are divided into special groups. In addition, there are fireplaces with local water heating, with which you can heat a small house. Such a fireplace has a special water tank in its design. The heated water in this tank, circulating through the pipes and heating radiators of the local heating system, is able to heat not only the room where the fireplace is directly installed, but the whole house.
Decorative fireplace. If it is not possible to install a chimney in the room or the area of \u200b\u200bthe room does not allow you to equip a classic fireplace, then you can build a decorative one. It will serve solely to create the required artistic style, to decorate and decorate the room. A decorative fireplace has two main structural elements: a frame and a cladding. As a rule, the frame is made of steel rods or a wooden beam with a cross section of at least 4×6 cm. Using hooks or brackets, the frame of the future fireplace is attached to the wall. From above, the frame is sheathed with chipboard plates. The slabs are painted with emulsion, enamel or oil paints to look like natural stone, brick, etc. Simulation of a burning flame can be performed by backlighting using a red light lamp. The light bulb can be overlaid with natural firewood. The body of a decorative fireplace can also be made from ordinary bricks. For these purposes, you will need a steel sheet (to isolate the brick structure from the floor), cement-lime mortar and, in fact, brick, preferably of good quality (about 20 pieces). A steel sheet is laid and attached to the floor. On it, adhering to all the rules of fireplace and stove masonry, with checking the verticality of the corners and walls, the horizontality of the rows, brickwork is performed. After that, the fireplace is properly lined, firewood is installed on the grate, and electric lighting is arranged. In addition, an electric fireplace, which is an electrical device that imitates the visual and thermal effects created by a gas or natural fireplace, can also be built into the body of a decorative fireplace.
The electric fireplace plays the role of not only a simple electric heater, but also imitates burning logs, flames or smoldering coals. Working in heater mode, it consumes about 1-2 kW and is able to heat a room up to 25 m2. In almost all modern electric fireplaces, the heating and decorative visualization modes work independently of each other. Typically, the body of an electric fireplace is made visually similar to a traditional fireplace insert, and sometimes in a hi-tech style. Electric fireplaces have a rich range of stylistic finishes – from cast iron to a combination of metal and glass.
There are also electric fireplaces on sale, which act as a complete solution, as an independent piece of furniture. Such fireplaces do not require additional financial costs for its installation, connection and decorative finishes. Traditional fireplace. The device of a traditional fireplace is not particularly difficult.
In order to build a fireplace with your own hands, you need to clearly know the principle of its operation, have elementary brickwork skills, understand the design features of the fireplace and strictly adhere to the proportions (ratio) of its main elements. The efficiency of the fireplace is in the range of 10 to 20%, since there are no smoke circulations in its design. The heating of the room occurs solely due to thermal radiation in the process of burning firewood, and all the air heated in the furnace freely leaves through the direct chimney into the pipe.
In the process of burning wood, oxygen-enriched cold room air is consumed. To maintain combustion, air must be supplied continuously and in sufficient volume. All the heated air goes into the pipe, not having time to transfer heat to the room. Heating of the room is carried out only by heating the walls of the firebox and radiating heat into the room. The design of the fireplace has two main elements – the firebox and the chimney.
In addition to these main components, the fireplace contains a large number of auxiliary functional elements, which we will consider in more detail. The base of any fireplace built at floor level is called a mantelpiece. It is made of refractory bricks or concrete. In front of the fireplace is the so-called pre-furnace area. It must be laid out from refractory bricks with jointing. It is allowed, in some cases, to use ordinary red brick, also with masonry, followed by jointing. On top of the pre-furnace platform, you can additionally lay a pre-furnace sheet on top. The width of the pre-furnace platform from the portal should be more than 25 cm on the sides and more than 50 cm in front.
The functional purpose of this site is to protect the floor from possible fire. On top of the fireplace table there is a special base (under) on which the firewood burns directly. Under must be placed above floor level to reduce the effect of drafts on the combustion process. Pods are arranged exclusively from refractory bricks. Firewood can be burned both directly on the surface of the hearth and on the grate. In some cases, a metal basket specifically designed for burning wood is used. Sometimes a special fireplace grate is installed in the opening of the fireplace portal, which, in addition to its decorative function, also serves to prevent burning logs from falling out of the furnace.
An ash chamber is located at the bottom of the fireplace, which is necessary to collect unburned fuel and ash, as well as to provide additional air flow to the burning wood through the grate. Experts recommend making the ash pan removable from sheet steel or tin in order to facilitate the process of cleaning the fireplace. The firebox of the fireplace is laid out from refractory bricks. The lining (cladding) of the firebox allows you to significantly increase the heat transfer of the fireplace. To enhance the heat-reflecting effect of the fireplace, it is recommended to line the back wall of the firebox with steel sheets or a cast-iron plate. As a rule, the back wall of the firebox is made with an inclination in its upper part at an angle of about 200, with the extension forward. Due to this, heat is reflected from the sloping part of the wall and directed towards the floor.
The portal is called the open part of the fireplace, which is the frame of the firebox. The portal can have a square, rectangular or semicircular shape. It performs mainly a decorative function. The portal can be decorated with a mantel made of concrete, granite, marble, etc. Its inner edge must be insulated, for example, with asbestos. As a rule, the distance from the edge of the grate to the “smoke” should be more than 25 cm.
A smoke chamber (smoke collector) is installed above the firebox. It most often has a pyramidal shape and serves to prevent the lowering of cold air flows into the firebox. On the back wall of the smoke collector there is a tray-like or flat bottom, which is called a smoke tooth. The smoke tooth serves to form a gas threshold. The main purpose of the gas threshold is to delay soot and prevent air flow fluctuations. In the immediate vicinity of the smoke tooth, a window is made, which is necessary for cleaning the chimney from soot. At the end of the smoke tooth, a rotary gate is placed. A conventional stove damper must be placed in a smoke box or in a chimney at a height of about 2 meters from the floor level. With the help of this valve, the traction force is controlled. In the intervals between the furnaces, the damper must be closed in order to prevent cold air from entering the chimney into the room.
The chimney must be built high enough to provide good draft to the fireplace. As a rule, the height of the chimney is from 5 to 10 meters. It is necessary that the pipe rises more than 1 meter above the roof ridge. Some types of fireplaces have special inserts for warm air. These fireplaces use a convection method of heating. In them, in the near-furnace space, a thermal chamber is specially installed that heats the cold air.
In such fireplaces, heat can be retained with the help of glass doors located in the firebox. The air supply can be adjusted using special holes located in the doors. In this case, there is a natural decrease in the amount of draft, and as a result, a smaller amount of warm air goes into the chimney.
One of the design features of the fireplace is the strict observance of the proportions, both of its main elements, and the compliance with the area of \u200b\u200bthe room where it will be directly installed. Too large a fireplace can cause hypothermia in the room and a source of constant drafts. Installing a fireplace that is too small will not allow you to heat the room to the required temperature.
When planning a fireplace, you must strictly follow a few “golden” rules:
• the area of the room should be approximately 50 times the area of the portal,
• the area of the hearth should be about 70% of the area of the portal,
• the cross section of the chimney should be approximately 10% of the area of the portal,
• the width and depth of the firebox must have an aspect ratio of 2:3 or 1:2,
• the height of the firebox should be about 70-80% of its width,
• the depth of the firebox should be 50-60% of its height. We pay special attention to the fact that the parameters of the firebox must strictly correspond to the height of the smoke box and the cross section of the chimney, otherwise the fireplace may constantly smoke. Below are a few examples of the dependence of the area of \u200b\u200bthe room on the size of the elements of the fireplace.
With room area, m2 20 30 40 portal area, m2 0.4 (70×56 cm) 0.63 (90×70 cm) 0.77 (100×77 cm) firebox depth, cm 35 40 42 firebox height, cm 36 36 36 firebox width, cm 45 60 70 chimney height, cm 63 70 80 chimney section, cm 14×27 27×27 27×27
We hope that this article has become not only interesting, but also useful for you. Knowing the principle of operation of the fireplace, its design features, as well as adhering to generally accepted rules and our recommendations, you can easily build a beautiful and functional fireplace with your own hands, which will give warmth, coziness and comfort to your home.