Photo by V.Balashova
1–6.Fireplaces and stoves, closed cast-iron or steel fireboxes of which are built into structures made of tiles pre-assembled in panels, for a long time (at least 2–4h) heat the room after the firewood has burned out. In terms of design and appearance, tiled claddings are very diverse.
ToUnfortunately, due to the small mass (no more than 100–190kg) a closed fireplace insert in terms of its thermal capabilities does not differ from stoves of low heat capacity: bourgeois stoves, temporary brick stoves andt.n. Fireplaces equipped with a closed firebox (especially thin-walled), on one laying of firewood, effectively heat the room for only a short time (no more than 1–2h). While the fire is burning, the air temperature rises sharply, but there is almost no heat accumulation in the building (due to contact with warm air, house structures heat up extremely slowly). Soon after the flame goes out, it becomes cold, because with proper ventilation in just 1h all the air, in which the heat generated by the fireplace is “dissolved”, is replaced by cool outdoor air. In order to get enough heat, the fireplace insert must be constantly fed with portions of fuel, which requires a certain skill, which is inherent only in professional stokers, and for homeowners accustomed to comfort, this is inconvenient.
From the depths of centuries
Photo by V.Balashova
7.Fireplace with closed hearth- decoration for any room of a country house, whether it be a kitchen, a drawing room or a bedroom. But such a device can become an effective heat generator only if there is a massive cladding or a heat accumulator.
8–9.Talcomagnesite- good material for production of furnaces and chimney facings for the closed fire chambers. This stone has a heat capacity 2.5 times greater than that of oven bricks.
ATAt the same time, stoves with a large heat capacity (the European stove, which heated, fed and treated more than one generation of our ancestors) are among them, the disadvantages of fireplace inserts and other stoves of low heat capacity are not characteristic. Such an oven can weigh from 500–750kg to several tons. Of course, before it heats up to the desired temperature, it will take quite a long time, sometimes several hours (unlike a fireplace, which starts heating the room as soon as the first torch lights up in it,- due to the radiation of thermal waves through the glass of the firebox). But on the other hand, the heat stored in the mass of the oven brick after the fuel burns out compensates for the heat loss of the house, not allowing the rooms for 10–24h neither overheat nor overcool. Realizing this, many manufacturers of fireplaces offer various technical solutions that allow you to transfer a fireplace with a closed firebox from the rank of furnaces of low heat capacity to the rank of furnaces of high heat capacity, “teach” it to store heat for future use. We will talk about some of these “recipes”.
First of all, let’s present a technical solution that is quite expensive, but very comfortable, environmentally friendly and adapted to our climate. These are fireplaces with heat-retaining lining, which is a monumental structure, often from floor to ceiling (it is supplied together with a fireplace insert in the form of a set of elements ready for installation). Fireplaces with such facings are placed against the wall, in the corner of the room, and sometimes in the middle of the room. Heat accumulates in the stone mass of their facings and heats the room for 4–15h after the fuel burns out. Heat transfer from heat-retaining fireplace linings is usually uniform, the air in the room remains warm for a long time, while the relative humidity is maintained at an optimal level (about 40%), and a particularly pleasant atmosphere reigns in the house. Heat accumulating claddings from the best manufacturers are distinguished by their elegant design, precise fitting of elements (heavy blocks of stone or concrete) and ease of installation. Since the claddings are often assembled using metal ties, they can be quickly and easily assembled and just as quickly dismantled to be transported to a new “place of residence”.
Photo by V. Kovalev
Photo by V.Balashova
Photo by V.Balashova
13–14.To increase the heat transfer time, the furnaces are ribbed and lined with fireclay.
fifteen.The thermoconcrete Brunner chimney is often built into the wall behind the fireplace.
16.Some furnace models are equipped with flue gas heat exchangers.- water”, which allow to accumulate heat in the liquid filling the heating system.
ATunlike heat-accumulating linings, thermally insulated linings almost do not accumulate heat in their mass. Moreover, there is practically no heat transfer through the heat-insulated lining to the fireplace room. To increase the heat capacity of the fireplace in this case, massive closed furnaces with thick walls and heat accumulators are required, passing through which the flue gases from the insert are sent to the chimney.
When choosing a firebox, first of all, pay attention to heavy cast-iron models. Great choice- firebox Keddy (Kennedygruppen, Sweden). The thickness of the walls of the monolithic body of Keddy fireboxes in some places reaches 18mm, which not only allows you to store heat, but also ensures their high strength. For example, Keddy 520 with curved glass with a capacity of 14kW weighs 145kg and costs about 70thousandrub. Seguin Duteries (France) offers for 45thousandrub. firebox Kiteflam with walls 8–12 thickmm (it is provided with a seven-year warranty). Thick-walled massive fireboxes are available from Tarnava (Poland) and Jotul (Norway).
You can consider the possibility of buying a steel insert, but necessarily covered from the inside (lined) with plates of heat-absorbing fireclay clay. When choosing a similar design, it must be remembered that in fireboxes with glass larger than 70
Photo by V. Kovalev
17–20.The role of the chimney section above the firebox can be played by heat accumulators made of stone(17,19,20) and cast iron(eighteen).
Directly above the closed fireplace insert, in the hood of the fireplace lining, you can install a small heat accumulator made of steel or cast iron, which will also be a section of the chimney. A cast iron chimney-convector finned on the outside is acceptable, for example Tarnava. If the dimensions of the cap allow, it is permissible to use two such heat accumulators at once, installing them one above the other. Steel convector chimneys in the form of a piece of pipe, to which 4–12 flat ribs are welded, are usually lighter than cast iron ones. They are good only for increasing the efficiency of the insert during fuel combustion (an increase in heat removal occurs due to the larger heat exchange surface of the chimney with room air). If you buy a steel chimney-convector equipped with a cylindrical metal mesh (the annular space between the chimney and the mesh is filled with fragments of talcomagnesite or other heat-intensive material), the heat accumulator will turn out to be excellent. Such a design has, for example, the Feringer chimney-convector, the length of which- 100cm and diameter- 11.5see inits grid can be loaded up to 50kg of stones; it costs about 2200thousandrub.
If the strength of the fireplace insert is high enough, a heat accumulator made of thermoconcrete and (or) fireclay can be placed directly above it. Such heat accumulators are usually made in the form of a “sandwich” of several heavy plates, in which there are through channels for the passage of flue gases (more often there are several flue channels, which allows increasing the contact area of flue gases with the heat storage material). The package of stone plates can be tightened with metal ties or a steel hoop.
Schmid is one of the leaders in terms of production of heat accumulators mounted above fireplace inserts. The “light” heat accumulator of this company, made of chamotte, is ringed with stainless steel on the outside. It accumulates thermal energy during the operation of the fireplace and gives it to the room after the end of combustion evenly and for a long time (up to 2–3h). “Heavy” fireclay heat accumulator is ringed outside with thermoconcrete. The efficiency of this system is higher- up to 3–4h. The air in the room during its use remains warm longer, the relative humidity is maintained at an optimal level. The cost of a heat accumulator of seven plates in EU is approximately 38thousandrub.
A heat accumulator located in the space above the chimney cassette is sometimes included in the “heat-storing cladding” kit+closed fireplace insert”. Such a tandem provides a serious increase in the heat transfer time of the fireplace. For example, Keddy branded linings for inserts are made of volcanic pumice- a fairly light material, which is nevertheless a good heat accumulator. Inside the cladding, a place is provided for a heat accumulator mounted above the furnace made of talcomagnesite plates. For example, the Regal / Mistral (Kennedygruppen) model weighs about 800kg (together with the firebox, lining and heat accumulator). According to the manufacturer, the heat generator cools down 10–15h, not allowing the cold to penetrate the house. You can buy Regal/Mistral for 150thousandrub.
I must say that it is often impossible to install a heat accumulator above the fireplace insert due to the design features of the firebox or lining (in the hood area). ATIn this case, flue gases can be discharged into the chimney through a floor heat storage located behind the fireplace or even on the floor above. Alas, such systems of long-term heat accumulation are non-volatile (up to 12–15h) can not always be done. The fact is that inside the floor heat accumulator, flue gases often follow a complex system of smoke channels with a sufficiently large aerodynamic resistance. Andthe rarefaction that a fireplace chimney is capable of creating is far from always enough to make the smoke “sweep out of the house.” Therefore, the chimney head located on the roof must be equipped with an electric fireplace fan designed to enhance draft, for example Turbocamino (O. Erre, Italy) costing 20thousandrub.
Among the ready-made solutions, it is worth noting the Brunner modular heat storage device (Germany). It is collected from heavy (about 20kg) corner elbows and at least weighty straight elements made of thermoconcrete,- all of them are easy to articulate and very durable. ATcross section of such a “stone chimney” is an octahedron (diagonal- around 30cm) with a round flue gas hole in the middle. Working temperature- before
More budget solution- connection of a fireplace to a heating shield, made in the form of a small attached or built-in wall with flue gas channels inside (usually 2–3 smoke turns are made), the mass of which is 600‑1000kg. During the operation of the fireplace, the flow of flue gases is removed from the house through the heating shield, giving off heat to the fireclay lining of its internal channels. This solution increases the efficiency of a fireplace with a closed firebox up to 80–90%. To use the fireplace in the warm season, in order not to overheat the house, it is logical to provide for a summer mode, when hot gases from the insert go through the shield along a short path or are generally removed directly into the chimney, bypassing the heating shield (for this, a flow splitter is built in directly behind the fireplace insert flue gases with two dampers). Since shields of this type are made for a specific country house and fireplace, it is most likely impossible to do without the services of a qualified specialist.
Cozy hearth in the apartment
Photo by V.BalashovaPhoto by V.Balashova Installing a solid fuel fireplace in a city apartment is not so easy. To do this, you must obtain permission from the executive authorities. BUTHere, a biofireplace can be installed and operated without informing anyone about it. Biofireplaces do not require connection to a chimney, but nevertheless they give a real, “live” fire, and in the process of burning the alcohol biofuel poured into them, soot, soot, ash or any harmful substances are not formed.- only water vapor and a small amount of carbon dioxide. Biofireplaces can be installed in any room of the apartment, whether it is a living room, an office or a bedroom. Thermal power of these devices- 0.5–3kW.
Water has a high heat capacity, which is at least 5times the heat capacity of any stone. Leading manufacturers of closed fireplace inserts provide for the possibility of accumulating the heat of flue gases in a mass of water or antifreeze that fills the heating system. For this, special fireboxes are produced.- fireplaces-boilers. Among the fireplaces-boilers, we note the models HWM-Konzept, Kompakt-Kessel B4/B5/B6 (Brunner). Godin fireplaces (France) are well-known in our country: models 851 CH, L’Osmos 680116, and Libourne 680117 with a black firebox decorated with steel inserts. The cost of these devices- 137–280thousandrub. Each of these models can transfer up to a maximum of 15 kW of heat to the heat carrier of the heating system, while the nominal power of the furnaces is 19–23kW. Worth mentioning is the I18 Jotul with flue gas heat exchanger- water.
It is inconvenient to use fireplaces-boilers as the only heat generator for a country house of permanent residence, since you will have to hire a stoker. BUThere in houses visited in the cold season by short trips, they fully justify themselves. Some models of fireplaces-boilers are also used to heat the water of the DHW system.
Developing this topic, it must be said that in Europe, where energy saving has recently been put at the forefront, volumetric heat storage boilers (multiboilers) are used that accumulate the heat of the fireplace. They are installed in the basement of a country house. Toother heat sources are also connected to such a heat accumulator, for example, ground source heat pumps, a gas or liquid fuel boiler, a solar collector, as well as heat consumers: radiators, underfloor heating, a hot water supply system, heat exchangers of ventilation units. Such a heat storage system is controlled by complex microprocessor automation that takes into account each kilowatt-hour of stored energy, analyzes the current needs of the house for heat and uses all the possibilities to minimize heat generation costs in order to reduce operating costs and not damage nature.