Creating an optimal microclimate and the consumption of thermal energy for heating a private house during the cold season largely depends on the thermal insulation properties building materials, from which this building was erected. One of these characteristics is heat capacity. This value must be taken into account when choosing building materials for constructing a private house. Therefore, the heat capacity of some building materials will be considered next.
Definition and formula of heat capacity
Each substance, to one degree or another, is capable of absorbing, storing and retaining thermal energy. To describe this process, the concept of heat capacity was introduced, which is the property of a material to absorb thermal energy when heating the surrounding air.
To heat any material with mass m from temperature t start to temperature t end, you will need to spend a certain amount of thermal energy Q, which will be proportional to the mass and temperature difference ΔT (t end -t start). Therefore, the heat capacity formula will look like this: Q = c*m*ΔТ, where c is the heat capacity coefficient ( specific value). It can be calculated using the formula: c = Q/(m* ΔT) (kcal/(kg* °C)).
Conventionally assuming that the mass of the substance is 1 kg, and ΔТ = 1°C, we can obtain that c = Q (kcal). This means that the specific heat capacity is equal to the amount of thermal energy that is expended to heat a material weighing 1 kg by 1°C.
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Using heat capacity in practice
Building materials with high heat capacity are used for the construction of heat-resistant structures. This is very important for private houses in which people live permanently. The fact is that such structures allow you to store (accumulate) heat, thanks to which the house maintains comfortable temperature enough for a long time. At first heating device heats the air and the walls, after which the walls themselves warm up the air. This allows you to save cash on heating and make your stay more comfortable. For a house in which people live periodically (for example, on weekends), the high thermal capacity of the building material will have the opposite effect: such a building will be quite difficult to heat quickly.
The heat capacity values of building materials are given in SNiP II-3-79. Below is a table of the main building materials and their specific heat capacity values.
Table 1
Brick has a high heat capacity, so it is ideal for building houses and constructing stoves.
Speaking about heat capacity, it should be noted that heating stoves It is recommended to build from brick, since the value of its heat capacity is quite high. This allows you to use the stove as a kind of heat accumulator. Thermal accumulators in heating systems(especially in water heating systems) are used more and more every year. Such devices are convenient because they only need to be heated well once with the intense fire of a solid fuel boiler, after which they will heat your home for a whole day or even more. This will significantly save your budget.
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Heat capacity of building materials
What should the walls of a private house be like in order to comply building regulations? The answer to this question has several nuances. To understand them, an example will be given of the heat capacity of the 2 most popular building materials: concrete and wood. has a value of 0.84 kJ/(kg*°C), and wood – 2.3 kJ/(kg*°C).
At first glance, you might think that wood is a more heat-intensive material than concrete. This is true, because wood contains almost 3 times more thermal energy than concrete. To heat 1 kg of wood you need to spend 2.3 kJ of thermal energy, but when cooling it will also release 2.3 kJ into space. Moreover, 1 kg concrete structure capable of accumulating and, accordingly, releasing only 0.84 kJ.
But don't rush to conclusions. For example, you need to find out what heat capacity 1 m2 of concrete and wooden wall 30 cm thick. To do this, you first need to calculate the weight of such structures. 1 m 2 given concrete wall will weigh: 2300 kg/m 3 *0.3 m 3 = 690 kg. 1 m 2 of wooden wall will weigh: 500 kg/m 3 * 0.3 m 3 = 150 kg.
- for a concrete wall: 0.84*690*22 = 12751 kJ;
- For wooden structure: 2.3*150*22 = 7590 kJ.
From the obtained result we can conclude that 1 m 3 of wood will accumulate heat almost 2 times less than concrete. An intermediate material in terms of heat capacity between concrete and wood is brickwork, a unit volume of which under the same conditions will contain 9199 kJ of thermal energy. At the same time, aerated concrete, as a building material, will contain only 3326 kJ, which will be significantly less than wood. However, in practice, the thickness of a wooden structure can be 15-20 cm, when aerated concrete can be laid in several rows, significantly increasing the specific heat capacity of the wall.
Before answering the main question - is fireclay brick harmful, you need to understand what kind of building material it is, in what areas and structures it is used and from what components it is made.
Most often, fireclay brick is used in the construction of stoves and fireplaces.
Conventional bricks used in construction are not suitable for structures that are constantly exposed to high temperatures. For such conditions, bricks made of refractory materials are used, the most popular of which is fireclay brick. It is difficult to imagine both private and industrial construction without its use.
The specific sandy-yellow color and coarse-grained structure make fireclay brick easily recognizable. The unusual properties of the material are given by the manufacturing technology, during which the raw materials are molded and fired at high temperatures. Moreover, their level at each stage is strictly controlled.
Fireclay bricks are made from a special type of clay.High performance (heat capacity and fire resistance) are achieved by the special composition of the feedstock. Fireclay bricks are made from special grades of clay (which are called “fireclay”) with the use of certain additives, in particular aluminum oxide. It is he who is “responsible” for the strength and durability of the building material and, most importantly, porosity, on which the heat capacity of fireclay bricks directly depends.
It is clear that the more aluminum oxide is added, the higher the porosity of the material and, accordingly, the lower the strength. Finding a balance between these two indicators is the most important thing in the production of fireclay bricks, and the heat capacity also depends on this.
Flaws
Based on the above, we can draw an unambiguous conclusion - the myth about the harmfulness of fireclay bricks has no basis in fact. Moreover, it is difficult to even simply explain the reason for its occurrence. It is quite possible that the material involuntarily “suffered” due to the fact that the very production of fireclay bricks, like most other building materials, especially before the arrival modern technologies, was often not a role model for defenders environment.
Be that as it may, the experience of many years of using the material allows us to unequivocally state that when exposed to high temperatures (even extremely high), absolutely no substances harmful to humans are released. It is difficult to expect otherwise, especially considering that in the production of fireclay bricks a material is used, the environmental purity of which is difficult to doubt, namely clay. You can even draw a parallel with pottery, which has accompanied humans for many hundreds of years.
Does this mean that fireclay bricks have no disadvantages? Of course not. Several main ones can be noted:
- Fireclay brick blocks are difficult to process and cut due to their high strength. This disadvantage is partially offset by the variety of shapes of fireclay brick blocks, which make it possible to achieve almost any design delight without cutting the material.
- Even in one batch of the product, deviations in the size of the bricks are noticeable, and achieving greater unification of the blocks is problematic due to the peculiarities of the production technology.
- The material is expensive compared to ordinary brick. It is also impossible to avoid this drawback: operating conditions require the use suitable material. The use of ordinary, non-fire-resistant bricks sharply reduces the service life of the structure or requires the use of additional funds its processing.
Characteristics
Fireclay brick is simply irreplaceable in the field of private construction when constructing stoves and fireplaces. But in order for the structure to be used long years, necessary quality material. This is especially true for private owners, since large industrial enterprises have more opportunities to control the materials used in construction.
And due to its high strength, fireclay bricks are difficult to cut and process.
All indicators of fireclay bricks - from strength to frost resistance, from porosity to density - are strictly regulated state standards. It is worth noting that in last years Some manufacturers in the production of fireclay bricks are guided by their own technical specifications. As a result, some discrepancies are possible on a number of parameters. Therefore, when purchasing material, it is imperative to check the certificate of conformity for product quality.
Should be paid Special attention the weight of bricks. The smaller it is, the higher the thermal conductivity and, accordingly, the lower the heat capacity. The optimal mass of the refractory block is determined by GOST within 3.7 kg.
Types and markings
Modern manufacturing plants offer a large number of the most various types fireclay bricks, which differ in weight and shape, production technology and degree of porosity.
The variety of shapes of fireclay bricks does not end with standard-shaped straight and arched blocks.
Trapezoidal and wedge-shaped ones are widely used, capable of satisfying any requirements for structural elements.
Depending on the degree of porosity, fireclay bricks can vary from extremely dense (less than 3% porosity) to ultra-lightweight (porosity 85% or more).
The main characteristics are very easy to determine by the marking of refractory bricks, which must be applied to each block. The following brands are currently produced:
- SHV, SHUS.
The thermal conductivity of these types of fireclay bricks allows them to be used in industry - for lining the walls of gas ducts of steam generators and convection shafts.
- SHA, ShB, SHAK.
The most versatile and therefore popular fireproof blocks, mostly used by private owners. They are used especially often when laying fireplaces and stoves. Can be used at temperatures up to 1690 degrees. In addition, they have high strength.
Used in the construction of coke production units.
A lightweight type of material used for lining furnaces with a relatively low heating temperature - no more than 1300 degrees. The low weight of refractory blocks is achieved by increasing the porosity index.
//www.youtube.com/watch?v=HrJ-oXlbD5U
It is the markings that must be studied first when purchasing a material, which will allow any builder to choose exactly the type of fireclay brick that is most suitable for the design features. And after studying the information provided, anyone can be sure that fireclay bricks do not pose any danger to humans, much less mythical harm.
The temperature inside the room depends on the thermal insulation properties of the material, which is why the thermal capacity of a brick is an important indicator that shows its ability to accumulate heat. Specific heat determined during laboratory studies, according to which, the most warm material is a solid brick. It is worth noting that the indicator depends on the type of brick material.
What it is?
The physical characteristic of heat capacity is inherent in any substance. It denotes the amount of heat that a physical body absorbs when heated by 1 degree Celsius or Kelvin. Mistakenly identify general concept with specific, since the latter implies the temperature required to heat one kilogram of a substance. It seems possible to accurately determine its number only in laboratory conditions. The indicator is necessary to determine the thermal resistance of the walls of a building and in the case when construction works carried out at sub-zero temperatures. For the construction of private and multi-storey buildings residential buildings and rooms, materials with high thermal conductivity are used, since they accumulate heat and maintain the temperature in the room.
The advantage of brick buildings is that they save on heating costs.
What does the heat capacity of bricks depend on?
The heat capacity coefficient is primarily affected by the temperature of the substance and state of aggregation, since the heat capacity of the same substance in the liquid and solid states differs in favor of the liquid. In addition, the volume of the material and the density of its structure are important. The more voids there are in it, the less it is able to retain heat inside itself.
Types of bricks and their indicators
Ceramic material used in furnaces.
More than 10 varieties are produced, differing in manufacturing technology. But silicate, ceramic, facing, fireproof and warm are more often used. Standard ceramic bricks are made from red clay with impurities and fired. Its heat index is 700-900 J/ (kg deg). It is considered quite resistant to high and low temperatures. Sometimes used for display stove heating. Its porosity and density vary and affect the heat capacity coefficient. Sand-lime brick consists of a mixture of sand, clay and additives. It can be full or empty, different sizes and, therefore, its specific heat capacity is equal to values from 754 to 837 J/ (kg deg). The advantage of silicate brickwork is good sound insulation even when laying the wall in one layer.
Facing bricks used for building facades have quite high density and heat capacity within 880 J/ (kg deg). Refractory brick is ideal for laying a furnace because it can withstand temperatures up to 1500 degrees Celsius. This subspecies includes fireclay, carborundum, magnesite and others. And the heat capacity coefficient (J/kg) is different:
Brick is a popular building material in the construction of buildings and structures. Many people only distinguish between red and white brick, but its types are much more diverse. They differ both in appearance (shape, color, size) and in properties such as density and heat capacity.
Traditionally, a distinction is made between ceramic and sand-lime brick who have different technology manufacturing. It is important to know that the density of brick, its specific heat capacity, and each type can differ significantly.
Ceramic brick is made from various additives and is fired. The specific heat capacity of ceramic brick is 700…900 J/(kg deg). The average density of ceramic bricks is 1400 kg/m3. The advantages of this type are: smooth surface, frost and water resistance, as well as resistance to high temperatures. The density of ceramic brick is determined by its porosity and can range from 700 to 2100 kg/m3. The higher the porosity, the lower the density of the brick.
Sand-lime brick has the following varieties: solid, hollow and porous; it has several standard sizes: single, one-and-a-half and double. The average density of sand-lime brick is 1600 kg/m3. The advantages of sand-lime brick are excellent soundproofing. Even if you lay thin layer made of such material, the sound insulation properties will remain at the proper level. The specific heat capacity of sand-lime brick ranges from 750 to 850 J/(kg deg).
The density values of various types of bricks and their specific (mass) heat capacity at various temperatures are presented in the table:
| Type of brick | Temperature, °C |
Density, kg/m 3 |
Heat capacity, J/(kg deg) |
|---|---|---|---|
| Trepelny | -20…20 | 700…1300 | 712 |
| Silicate | -20…20 | 1000…2200 | 754…837 |
| Adobe | -20…20 | — | 753 |
| Red | 0…100 | 1600…2070 | 840…879 |
| Yellow | -20…20 | 1817 | 728 |
| Building | 20 | 800…1500 | 800 |
| Facing | 20 | 1800 | 880 |
| Dinas | 100 | 1500…1900 | 842 |
| Dinas | 1000 | 1500…1900 | 1100 |
| Dinas | 1500 | 1500…1900 | 1243 |
| Carborundum | 20 | 1000…1300 | 700 |
| Carborundum | 100 | 1000…1300 | 841 |
| Carborundum | 1000 | 1000…1300 | 779 |
| Magnesite | 100 | 2700 | 930 |
| Magnesite | 1000 | 2700 | 1160 |
| Magnesite | 1500 | 2700 | 1239 |
| Chromite | 100 | 3050 | 712 |
| Chromite | 1000 | 3050 | 921 |
| Chamotte | 100 | 1850 | 833 |
| Chamotte | 1000 | 1850 | 1084 |
| Chamotte | 1500 | 1850 | 1251 |
It is necessary to note another popular type of brick – facing brick. He is not afraid of either moisture or cold. The specific heat capacity of the facing brick is 880 J/(kg deg). The facing brick has shades from bright yellow to fiery red. This material can be used to produce both finishing and facing works. The density of this type of brick is 1800 kg/m3.
It is worth noting a separate class of bricks - refractory bricks. This class includes dinas, carborundum, magnesite and fireclay bricks. Refractory bricks are quite heavy - the density of bricks of this class can reach 2700 kg/m3.
Carborundum brick has the lowest heat capacity at high temperatures - it is 779 J/(kg deg) at a temperature of 1000°C. Masonry made from such bricks warms up much faster than fireclay bricks, but retains heat less well.
Refractory bricks are used in the construction of furnaces with operating temperatures up to 1500°C. The specific heat capacity of refractory bricks depends significantly on temperature. For example, the specific heat capacity of fireclay bricks is 833 J/(kg deg) at 100°C and 1251 J/(kg deg) at 1500°C.
Sources:
- Franchuk A. U. Tables of thermal technical indicators of building materials, M.: Research Institute of Construction Physics, 1969 - 142 p.
- Tables of physical quantities. Directory. Ed. acad. I. K. Kikoina. M.: Atomizdat, 1976. - 1008 p. construction physics, 1969 - 142 p.
The creation of an optimal microclimate and the consumption of thermal energy for heating a private house during the cold season largely depends on the thermal insulation properties of the building materials from which the building is constructed. One of these characteristics is heat capacity. This value must be taken into account when choosing building materials for constructing a private house. Therefore, the heat capacity of some building materials will be considered next.
To heat any material with mass m from temperature t start to temperature t end, you will need to spend a certain amount of thermal energy Q, which will be proportional to the mass and temperature difference ΔT (t end -t start). Therefore, the heat capacity formula will look like this: Q = c*m*ΔT, where c is the heat capacity coefficient (specific value). It can be calculated using the formula: c = Q/(m* ΔT) (kcal/(kg* °C)).
Table 1
What should the walls of a private house be like in order to comply with building codes? The answer to this question has several nuances. To understand them, an example will be given of the heat capacity of the 2 most popular building materials: concrete and wood. The heat capacity of concrete is 0.84 kJ/(kg*°C), and that of wood is 2.3 kJ/(kg*°C).
At first glance, you might think that wood is a more heat-intensive material than concrete. This is true, because wood contains almost 3 times more thermal energy than concrete. To heat 1 kg of wood you need to spend 2.3 kJ of thermal energy, but when cooling it will also release 2.3 kJ into space. At the same time, 1 kg of concrete structure can accumulate and, accordingly, release only 0.84 kJ.
From the obtained result we can conclude that 1 m 3 of wood will accumulate heat almost 2 times less than concrete.
The intermediate material in terms of heat capacity between concrete and wood is brickwork, a unit volume of which under the same conditions will contain 9199 kJ of thermal energy. At the same time, aerated concrete, as a building material, will contain only 3326 kJ, which will be significantly less than wood. However, in practice, the thickness of a wooden structure can be 15-20 cm, when aerated concrete can be laid in several rows, significantly increasing the specific heat capacity of the wall.
Tree
Brick
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How is specific heat capacity determined?
Specific heat capacity is determined during laboratory tests. This indicator completely depends on what temperature the material has. The heat capacity parameter is necessary so that in the end you can understand how heat resistant they will be external walls heated building. After all, the walls of buildings must be built from materials whose specific heat capacity tends to a maximum.
In addition, this indicator is necessary for making accurate calculations in the process of heating various types of solutions, as well as in situations where work is carried out at sub-zero temperatures.
It is impossible not to say about solid bricks. This material boasts a high thermal conductivity. Therefore, in order to save money, hollow bricks come in handy.
Types and nuances of brick blocks
In order to eventually build a sufficiently warm brick building, initially you need to understand what type of this material is best suited for this. Currently, a huge assortment of bricks is available in markets and construction stores. So which one should you prefer?
In our country, sand-lime brick is extremely popular among buyers. This material is obtained by mixing lime with sand.
The demand for sand-lime brick is due to the fact that it is often used in everyday life and has a fairly reasonable price. If we touch on the issue of physical quantities, then this material, of course, is in many ways inferior to its counterparts. Due to the low thermal conductivity, build a truly warm house It is unlikely that it will work out of sand-lime brick.
But, of course, like any material, sand-lime brick has its advantages. For example, it has a high sound insulation rate. It is for this reason that it is very often used for the construction of partitions and walls in city apartments.
Ceramic brick takes second place in the demand ranking. It is obtained by mixing various types of clays, which are subsequently fired. This material is used for the direct construction of buildings and their cladding. Construction type used for the construction of buildings, and facing - for their decoration. It is also worth mentioning that ceramic-based bricks are very light in weight, so they are an ideal material for independent construction work.
New construction market is warm brick. This is nothing more than an advanced ceramic block. This type can be approximately fourteen times larger in size than the standard. But this in no way affects the total weight of the building.
If we compare this material with ceramic bricks, then the first option in terms of thermal insulation is twice as good. U warm block there are a large number of small voids that look like channels located in a vertical plane.
And as you know, the more air space is present in the material, the higher the thermal conductivity. Heat loss in this situation occurs in most cases on the partitions inside or in the joints of the masonry.
Thermal conductivity of bricks and foam blocks: features
This calculation is necessary so that it is possible to reflect the properties of the material, which are expressed in relation to the density of the material to its ability to conduct heat.
Thermal uniformity is an indicator that is equal to the inverse ratio of the heat flow passing through the wall structure to the amount of heat passing through a conditional barrier and equal to the total area of the wall.
In fact, both calculation options are quite complex process. It is for this reason that if you do not have experience in this matter, then it is best to seek help from a specialist who can accurately make all the calculations.
So, to summarize, we can say that physical quantities are very important when choosing a building material. How could you see different types bricks, depending on their properties, have a number of advantages and disadvantages. For example, if you want to build a really warm building, then it is best for you to give preference warm look brick, whose thermal insulation indicator is at the maximum level. If you are limited in money, then the best option You will be better off buying sand-lime brick, which, although it retains heat minimally, does an excellent job of eliminating extraneous sounds from the room.
1pokirpichy.ru
Definition and formula of heat capacity
Each substance, to one degree or another, is capable of absorbing, storing and retaining thermal energy. To describe this process, the concept of heat capacity was introduced, which is the property of a material to absorb thermal energy when heating the surrounding air.
To heat any material with mass m from temperature t start to temperature t end, you will need to spend a certain amount of thermal energy Q, which will be proportional to the mass and temperature difference ΔT (t end -t start). Therefore, the heat capacity formula will look like this: Q = c*m*ΔТ, where c is the heat capacity coefficient (specific value). It can be calculated using the formula: c = Q/(m* ΔT) (kcal/(kg* °C)).
Conventionally assuming that the mass of the substance is 1 kg, and ΔТ = 1°C, we can obtain that c = Q (kcal). This means that the specific heat capacity is equal to the amount of thermal energy that is expended to heat a material weighing 1 kg by 1°C.
Using heat capacity in practice
Building materials with high heat capacity are used for the construction of heat-resistant structures. This is very important for private houses in which people live permanently. The fact is that such structures allow you to store (accumulate) heat, thanks to which the house maintains a comfortable temperature for quite a long time. First, the heating device heats the air and the walls, after which the walls themselves warm the air. This allows you to save money on heating and make your stay more comfortable. For a house in which people live periodically (for example, on weekends), the high thermal capacity of the building material will have the opposite effect: such a building will be quite difficult to heat quickly.
The heat capacity values of building materials are given in SNiP II-3-79. Below is a table of the main building materials and their specific heat capacity values.
Table 1
Brick has a high heat capacity, so it is ideal for building houses and constructing stoves.
Speaking about heat capacity, it should be noted that heating stoves are recommended to be built from brick, since the value of its heat capacity is quite high. This allows you to use the stove as a kind of heat accumulator. Heat accumulators in heating systems (especially in water heating systems) are used more and more every year. Such devices are convenient because they only need to be heated well once with the intense fire of a solid fuel boiler, after which they will heat your home for a whole day or even more. This will significantly save your budget.
Heat capacity of building materials
What should the walls of a private house be like in order to comply with building codes? The answer to this question has several nuances. To understand them, an example will be given of the heat capacity of the 2 most popular building materials: concrete and wood. The heat capacity of concrete is 0.84 kJ/(kg*°C), and that of wood is 2.3 kJ/(kg*°C).
At first glance, you might think that wood is a more heat-intensive material than concrete. This is true, because wood contains almost 3 times more thermal energy than concrete. To heat 1 kg of wood you need to spend 2.3 kJ of thermal energy, but when cooling it will also release 2.3 kJ into space. At the same time, 1 kg of concrete structure can accumulate and, accordingly, release only 0.84 kJ.
But don't rush to conclusions. For example, you need to find out what heat capacity 1 m 2 of concrete and wooden walls 30 cm thick will have. To do this, you first need to calculate the weight of such structures. 1 m2 of this concrete wall will weigh: 2300 kg/m3 * 0.3 m3 = 690 kg. 1 m 2 of wooden wall will weigh: 500 kg/m 3 * 0.3 m 3 = 150 kg.
- for a concrete wall: 0.84*690*22 = 12751 kJ;
- for a wooden structure: 2.3*150*22 = 7590 kJ.
From the obtained result we can conclude that 1 m 3 of wood will accumulate heat almost 2 times less than concrete. An intermediate material in terms of heat capacity between concrete and wood is brickwork, a unit volume of which under the same conditions will contain 9199 kJ of thermal energy. At the same time, aerated concrete, as a building material, will contain only 3326 kJ, which will be significantly less than wood. However, in practice, the thickness of a wooden structure can be 15-20 cm, when aerated concrete can be laid in several rows, significantly increasing the specific heat capacity of the wall.
Use of various materials in construction
Tree
For comfortable living in a home, it is very important that the material has high heat capacity and low thermal conductivity.
In this regard, wood is the best option for houses not only for permanent but also for temporary residence. A wooden building that is not heated for a long time will respond well to changes in air temperature. Therefore, heating of such a building will occur quickly and efficiently.
Mainly used in construction conifers: pine, spruce, cedar, fir. In terms of price-quality ratio the best option is pine. Whatever you choose to design wooden house, you need to consider the following rule: the thicker the walls, the better. However, here you also need to take into account your financial capabilities, since with an increase in the thickness of the timber, its cost will increase significantly.
Brick
This building material has always been a symbol of stability and strength. The brick has good strength and resistance to negative influences external environment. However, if we take into account the fact that brick walls are mainly designed with a thickness of 51 and 64 cm, then to create good thermal insulation they additionally need to be covered with a layer thermal insulation material. Brick houses great for permanent residence. Once heated, such structures are capable of releasing the heat accumulated in them into space for a long time.
When choosing a material for building a house, you should take into account not only its thermal conductivity and heat capacity, but also how often people will live in such a house. Right choice will allow you to maintain coziness and comfort in your home throughout the year.
You may be interested in: drilling a water well in Kaluga: the cost is reasonable
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Specific heat capacity of materials
Heat capacity is a physical quantity that describes the ability of a material to accumulate temperature from a heated environment. Quantitatively, specific heat capacity is equal to the amount of energy, measured in J, required to heat a body weighing 1 kg by 1 degree.
Below is a table of the specific heat capacity of the most common materials in construction.
- type and volume of heated material (V);
- the specific heat capacity of this material (Sud);
- specific gravity (msp);
- initial and final temperatures of the material.
Heat capacity of building materials
The heat capacity of materials, the table for which is given above, depends on the density and thermal conductivity of the material.
And the thermal conductivity coefficient, in turn, depends on the size and closedness of the pores. A fine-porous material, which has a closed pore system, has greater thermal insulation and, accordingly, lower thermal conductivity than a large-porous one.
This is very easy to see using the most common materials in construction as an example. The figure below shows how the thermal conductivity coefficient and the thickness of the material influence the thermal insulation properties of external fences.
The figure shows that building materials with lower density have a lower thermal conductivity coefficient.
However, this is not always the case. For example, there are fibrous types of thermal insulation for which the opposite pattern applies: the lower the density of the material, the higher the thermal conductivity coefficient will be.
Therefore, you cannot rely solely on the indicator of the relative density of the material, but it is worth taking into account its other characteristics.
Comparative characteristics of the heat capacity of basic building materials
In order to compare the heat capacity of the most popular building materials, such as wood, brick and concrete, it is necessary to calculate the heat capacity for each of them.
First of all, you need to decide on the specific gravity of wood, brick and concrete. It is known that 1 m3 of wood weighs 500 kg, brick - 1700 kg, and concrete - 2300 kg. If we take a wall whose thickness is 35 cm, then through simple calculations we find that the specific gravity of 1 square meter of wood will be 175 kg, brick - 595 kg, and concrete - 805 kg.
Next, we will select the temperature value at which thermal energy will accumulate in the walls. For example, this will happen on a hot summer day with an air temperature of 270C. For the selected conditions, we calculate the heat capacity of the selected materials:
- Wall made of wood: C=SudhmuddhΔT; Sder=2.3x175x27=10867.5 (kJ);
- Concrete wall: C=SudhmuddhΔT; Cbet = 0.84x805x27 = 18257.4 (kJ);
- Brick wall: C=SudhmuddhΔT; Skirp = 0.88x595x27 = 14137.2 (kJ).
From the calculations made, it is clear that with the same wall thickness, concrete has the highest heat capacity, and wood has the least. What does this mean? This suggests that on a hot summer day, the maximum amount of heat will accumulate in a house made of concrete, and the least amount of heat will accumulate in a house made of concrete.
This explains the fact that in wooden house In hot weather it is cool, and in cold weather it is warm. Brick and concrete easily accumulate a fairly large amount of heat from the environment, but just as easily part with it.
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STRAW in CONSTRUCTION
In the village of Taptykovo Res. Bashkortostan built energy efficient house
made of laminated veneer lumber with insulation, built by engineer Alfred Fayzullin.
This is the first house in the Republic of Bashkortostan that meets Green Standards.
New generation house: hot water from the sun, and savings on heating due to insulation.
Although economical, the house combines energy efficiency, environmental friendliness and modern style.
In the morning the sun illuminates the entire house from the south side, and in the evening - from the west. The location of the windows here is thought out to the smallest detail. Five-chamber windows are also part of energy-saving technology.
The glass is made using silver, which allows it to reflect heat.
A special feature of this house is that there is no need for heating. traditional methods and low power consumption.
Alternative energy sources are used here - solar collector and a heat pump.
Application of the system supply and exhaust ventilation with heat recovery creates a favorable indoor microclimate. The house uses windows and doors with high thermal resistance. The “City Corner” assembly technology ensures the absence of “cold bridges” around the entire perimeter of the house, thanks to a continuous layer of insulation. All this eliminates large heat losses and significantly reduces heating costs (two to three times compared to gas heating). The cost of such a turnkey house varies from 30 thousand rubles per square meter, depending on the area of the house, its equipment, and finishing materials.
“This is a very interesting, modern and timely project, technologies of tomorrow.
This mechanism is only part of an energy-efficient private house in Taptykovo.
The owner of this unique structure and its inventor. He says that during the construction of the “green house” passive laminated veneer lumber which allows you to retain heat. The material from which it is made is now produced by the Uchalinsky enterprise.
Application heat pump instead of an electric boiler. It effectively uses environmental heat for heating and hot water supply at home and allows you to save energy consumption by up to 29 times.
On hot days, this technology serves to cool the premises.
There are only a few such houses in Russia so far.
When designing it, Alfred Faizullin used Japanese and German technologies.
He notes that during the operation and disposal of the house, the structure will not have any impact on nature.
Smart a private house They plan to improve it in the future.
The designers want to use a hydraulic accumulator and also create a heat accumulator.
The water temperature in a 300 m³ tank, even in cloudy weather, does not fall below 40 degrees
As a source of thermal energy, the engineer purchased a Viessmann heat pump with a power of 9.7 kW.
I had to pay 424,000 rubles for the heat pump.
Vertical probes were placed in two wells, each 63 meters deep.
Drilling cost 1,600 rubles per linear meter
Let's make a reservation right away: Alfred Fayzullin built a house for himself and did not skimp on technology, choosing the best. As a result, the cost square meter“turnkey” amounted to 45,000 rubles. The total area of the house is 180 m2.
Passive house must consume no more than 10% from the traditional pump with a power of 9.7 kW. too much for such a house.
The standard for a passive house is 15 kW. per m2 international requirement for harsh climates for the heating season.
15 kW/213 days * 180 m2= 12.7 kW/m2 norm per day or 380 kW for 30 days.
How to build it yourself inexpensive warm house, with your own hands, we have the answer, you are at the right place, find out the details, how to make your own solar heating.
The smart one is not the one who has more opportunities, but the one who has a lot of ideas in his head.
Happy is not the person who has a lot of money, but the one who has more wisdom.
The richest man is not the one who has more money, and the one who needs less.
The smart one is not the one who earns a living, but the wise one for whom the smart one works.
The age of business today, the strong take away from the weak, the smart take away from the strong.
A person is not happy when more good, and who needs even less.
Money rules the world, the more of it, the more rights.
There is an idea, there is no means to implement it, we need wise solutions for smart thoughts.
It is not the one who has more money who is successful, but the one who has more ideas put into practice.
It is possible to know, but to be able to do it is more difficult; there is a big gap between them.
straw-house.ru
Ceramic
Based on production technology, bricks are classified into ceramic and silicate groups. Moreover, both types have significant differences in material density, specific heat capacity and thermal conductivity coefficient. The raw material for the manufacture of ceramic bricks, also called red bricks, is clay, to which a number of components are added. The formed raw blanks are fired in special ovens. The specific heat capacity can vary between 0.7-0.9 kJ/(kg K). As for the average density, it is usually at the level of 1400 kg/m3.
Among strengths ceramic bricks can be distinguished:
1. Smoothness of the surface. This increases its external aesthetics and ease of installation.
2. Resistance to frost and moisture. Under normal conditions, walls do not require additional moisture and thermal insulation.
3. Ability to withstand high temperatures. This allows the use of ceramic bricks for the construction of stoves, barbecues, and heat-resistant partitions.
4. Density 700-2100 kg/m3. This characteristic is directly affected by the presence of internal pores. As the porosity of a material increases, its density decreases and its thermal insulation characteristics increase.
Silicate
As for sand-lime brick, it can be solid, hollow and porous. Based on the size, there are single, one-and-a-half and double bricks. On average, sand-lime brick has a density of 1600 kg/m3. The noise-absorbing characteristics of silicate masonry are especially appreciated: even if we're talking about about a wall of small thickness, the level of its sound insulation will be an order of magnitude higher than in the case of using other types of masonry material.
Facing
Separately, it is worth mentioning the facing brick, which with equal success resists both water and increased temperature. The specific heat capacity of this material is at the level of 0.88 kJ/(kg K), with a density of up to 2700 kg/m3. On sale facing bricks presented in a wide variety of shades. They are suitable for both cladding and laying.
Refractory
Represented by dinas, carborundum, magnesite and fireclay bricks. The mass of one brick is quite large due to its significant density (2700 kg/m3). The lowest heat capacity when heated is carborundum brick 0.779 kJ/(kg K) for a temperature of +1000 degrees. The heating rate of a furnace laid from this brick significantly exceeds the heating of fireclay masonry, but cooling occurs faster.
Furnaces are built from refractory bricks, providing heating up to +1500 degrees. The specific heat capacity of a given material is greatly influenced by the heating temperature. For example, the same fireclay brick at +100 degrees has a heat capacity of 0.83 kJ/(kg K). However, if it is heated to +1500 degrees, this will provoke an increase in heat capacity to 1.25 kJ/(kg K).
Dependence on temperature of use
The technical performance of bricks is greatly influenced by temperature regime:
- Trepelny. At temperatures from -20 to + 20, the density varies within 700-1300 kg/m3. The heat capacity indicator is at a stable level of 0.712 kJ/(kg K).
- Silicate. A similar temperature regime of -20 - +20 degrees and a density from 1000 to 2200 kg/m3 provides the possibility of different specific heat capacities of 0.754-0.837 kJ/(kg K).
- Adobe. When the temperature is identical to the previous type, it demonstrates a stable heat capacity of 0.753 kJ/(kg K).
- Red. Can be used at temperatures of 0-100 degrees. Its density can vary from 1600-2070 kg/m3, and its heat capacity can range from 0.849 to 0.872 kJ/(kg K).
- Yellow. Temperature fluctuations from -20 to +20 degrees and a stable density of 1817 kg/m3 gives the same stable heat capacity of 0.728 kJ/(kg K).
- Building. At a temperature of +20 degrees and a density of 800-1500 kg/m3, the heat capacity is at the level of 0.8 kJ/(kg K).
- Facing. The same temperature regime of +20, with a material density of 1800 kg/m3, determines the heat capacity of 0.88 kJ/(kg K).
- Dinas. Operation in elevated temperature from +20 to +1500 and a density of 1500-1900 kg/m3 implies a consistent increase in heat capacity from 0.842 to 1.243 kJ/(kg K).
- Carborundum. As it heats from +20 to +100 degrees, a material with a density of 1000-1300 kg/m3 gradually increases its heat capacity from 0.7 to 0.841 kJ/(kg K). However, if the heating of the carborundum brick is continued further, its heat capacity begins to decrease. At a temperature of +1000 degrees it will be equal to 0.779 kJ/(kg K).
- Magnesite. A material with a density of 2700 kg/m3 with an increase in temperature from +100 to +1500 degrees gradually increases its heat capacity of 0.93-1.239 kJ/(kg K).
- Chromite. Heating a product with a density of 3050 kg/m3 from +100 to +1000 degrees provokes a gradual increase in its heat capacity from 0.712 to 0.912 kJ/(kg K).
- Chamotte. It has a density of 1850 kg/m3. When heated from +100 to +1500 degrees, the heat capacity of the material increases from 0.833 to 1.251 kJ/(kg K).
Select the bricks correctly, depending on the tasks at the construction site.
kvartirnyj-remont.com
TYPES OF BRICKS
SILICATE
The thermal conductivity of this type is on average 0.7 W/(m oC). This is a fairly low figure compared to other materials. That's why warm walls This type of brick will most likely not work.
CERAMIC
- Building,
- Facing.
- Full-bodied – 0.6 W/m* oC;
- Hollow brick - 0.5 W/m* oC;
- Slot – 0.38 W/m* oC.
The average heat capacity of a brick is about 0.92 kJ.
WARM CERAMICS
Warm brick is a relatively new building material. In principle, it is an improvement on the usual ceramic block.
Thermal insulation properties are almost 2 times better compared to ceramic bricks. The thermal conductivity coefficient is approximately 0.15 W/m* oC.
stroy-bloks.ru
Types of bricks
In order to answer the question: “how to build a warm house from brick?”, you need to find out what type of brick is best to use. Because modern market offers huge selection of this building material. Let's look at the most common types.
Silicate
Sand-lime bricks are the most popular and widely used in construction in Russia. This type made by mixing lime and sand. This material has become very widespread due to its wide range of applications in everyday life, and also due to the fact that its price is quite low.
However, if you turn to physical quantities this product, then not everything is so smooth.
Let's consider double sand-lime brick M 150. The M 150 brand indicates high strength, so it even approaches natural stone. Dimensions are 250x120x138 mm.
The thermal conductivity of this type is on average 0.7 W/(m o C). This is a fairly low figure compared to other materials. Therefore, warm walls made of this type of brick most likely will not work.
An important advantage of such bricks compared to ceramic ones is their soundproofing properties, which have a very beneficial effect on the construction of walls enclosing apartments or dividing rooms.
Ceramic
Second place in popularity building bricks reasonably given to ceramic ones. To produce them, various mixtures of clays are fired.
This type is divided into two types:
- Building,
- Facing.
Construction bricks are used for the construction of foundations, walls of houses, stoves, etc., and facing bricks are used for finishing buildings and premises. This material is more suitable for DIY construction, as it is much lighter than silicate.
The thermal conductivity of a ceramic block is determined by the thermal conductivity coefficient and is numerically equal to:
- Full-bodied – 0.6 W/m* o C;
- Hollow brick - 0.5 W/m* o C;
- Slot – 0.38 W/m* o C.
The average heat capacity of a brick is about 0.92 kJ.
Warm ceramics
Warm brick is a relatively new building material. In principle, it is an improvement on the conventional ceramic block.
This type of product is much larger than usual; its dimensions can be 14 times larger than standard ones. But this does not greatly affect the overall weight of the structure.
Thermal insulation properties are almost 2 times better compared to ceramic bricks. The thermal conductivity coefficient is approximately 0.15 W/m* o C.
A block of warm ceramics has many small voids in the form of vertical channels. And as mentioned above, the more air in the material, the higher the thermal insulation properties of this building material. Heat loss can occur mainly on internal partitions or in masonry joints.
Summary
We hope our article will help you understand the large number of physical parameters of bricks and choose the most suitable one for yourself. suitable option by all indicators! And the video in this article will provide Additional information on this topic, see.
