INTERNATIONAL JOURNAL OF ARTIFICIAL INTELLIGENCE
ISSN: 2692-5206, Impact Factor: 12,23
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Journal:
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INCREASING THE ENERGY EFFICIENCY OF RESIDENTIAL BUILDINGS'
EXTERIOR WALLS MADE OF GASO-CONCRETE BLOCKS
Kulmirzayev Jaxongir Ilxomiddinovich
Basic doctoral student of the Samarkand State University of Architecture and Construction
named after Mirzo Ulugbek (SamSACU)
+99893-998-19-93
G’.Shukurov
Scientific supervisor: candidate of technical sciences, professor
Abstract:
This article presents the results of theoretical and practical studies conducted on a
sample of external walls made of aerated concrete blocks in order to improve the operational
characteristics and energy efficiency of external walls of residential buildings made of
aerated concrete blocks. As a result of the studies, the total heat transfer resistance of the
sample of external walls of residential buildings made of thermally improved aerated
concrete blocks, the coefficient of thermal conductivity of wall layers, the heat flow passing
through the wall, the temperature in the wall layers and the heat resistance of the wall for the
summer season were determined. The conducted theoretical thermal-physical studies were
compared with practical studies conducted on the wall model, and recommendations were
developed to increase the thermal protection of external walls of buildings being built based
on modern projects.
Keywords:
Aerated concrete, external walls, heat transfer resistance, thermal conductivity
coefficient, heat flow.
Introduction.
The future of our country is closely related to the development of
construction and construction equipment. That is why this area is always in the government's
attention. In recent years, the production of aerated concrete and brick, small wall blocks has
increased somewhat in our republic. These materials are widely used by the population in
individual housing construction, along with pakhsa, raw brick, sinch and guvala. An increase
in the number of floors in the construction of individual houses, an increase in the level of
amenities created in houses is observed. Currently, public, residential and agricultural
buildings made of aerated concrete blocks are being used in good condition. Most of such
buildings are frame, and their long-term durability is designed for more than 100 years.
However, since these buildings do not meet the thermal protection requirements of BR
2.01.04-97*, it is necessary to increase their thermal protection. As a result of the research, it
was possible to provide practical recommendations on improving the thermal physical
properties of the external walls of residential buildings during the overhaul and increase their
energy efficiency. Therefore, for conducting thermal-physical experiments, a sample of
aerated concrete blocks measuring 600x400x300 mm was installed in the laboratory of the
Department of “Buildings and Structures” of SamSACI, and thermal-physical experimental
research was carried out.
INTERNATIONAL JOURNAL OF ARTIFICIAL INTELLIGENCE
ISSN: 2692-5206, Impact Factor: 12,23
American Academic publishers, volume 05, issue 05,2025
Journal:
https://www.academicpublishers.org/journals/index.php/ijai
page 257
By increasing the thermal insulation of external envelopes, it is possible to increase
the energy efficiency of buildings. Therefore, it is important to use energy-efficient external
envelopes in the design and construction of buildings and structures. Therefore, in order to
increase the energy efficiency of buildings, various structural solutions for external walls
have been recommended. The construction of low-energy buildings mainly depends on the
following criteria. This can be achieved by the following methods:
1. By increasing the thermal insulation of external envelopes;
2. Through energy-efficient structural solutions for external envelopes;
3. By using solar energy in the process of heating buildings;
4. By using non-conventional energy sources;
5. By using geothermal heat sources;
6. By using wind energy;
7. By using river and sea water.
The experiments conducted in the field of heat physics are as follows:
1. Increasing the thermal protection of external barrier structures, that is, increasing
the thermal insulation of their external walls in the process of reconstruction and major
repairs of buildings;
2. Increasing energy efficiency by improving the thermal insulation of the external
walls of buildings. As a result of the conducted theoretical and practical studies, it became
known that often when a thermal insulation layer is installed on the inner surface of some
external barrier structures, condensation moisture forms in certain layers of the structure. This
situation does not meet the requirements of BR 2.01.04-97*. As is known, in accordance with
the requirements of BR 2.01.04.-97٭, it is required to increase the thermal protection of the
external walls of residential buildings, medical treatment, children's institutions, schools,
boarding schools, colleges, lyceums, educational institutions, as well as public and industrial
buildings during construction, reconstruction and major repairs. To theoretically substantiate
this issue, it is necessary to determine the total heat transfer resistance of the external walls of
residential buildings made of aerated concrete blocks under repair. This resistance is
determined in the following manner:
1. First of all, the initial data is accepted, namely the type of building and the
constructive solution of the energy-efficient external wall with aerated concrete blocks, as
well as its calculation scheme;
2. Based on BR 02.01.04-97*, the required heat transfer resistance of the external walls of
buildings that meet the minimum sanitary and hygienic requirements is determined using the
following formula [3]:
R
u
zar
=
n t
i
− t
t
∆t
m
∙ α
i
; (1.1)
INTERNATIONAL JOURNAL OF ARTIFICIAL INTELLIGENCE
ISSN: 2692-5206, Impact Factor: 12,23
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where: n - is the coefficient indicating the position of the outer surface of the external
barrier structure relative to the outside air. Taken from Table 3 of BR 02.01.04-97*;
t
u
-
indoor air temperature, this indicator is accepted from the QMQs for the suitability of
buildings,
℃
.
t
t
- estimated outdoor temperature (average coldest 5-day outdoor temperature
is taken),
℃
. This size is adopted from QMQ 02.01.01-94;
∆t
m
- The standard difference
between the internal surface temperature of an external barrier structure and the internal air
temperature,
℃
. This value is taken from Table 4 of QMQ 02.01.04-97* and this difference is
written as follows:
∆t
m
= t
i
− τ
i
; (1.2)
Depending on the type of barrier structure and its surfaces, the heat transfer
coefficient of the internal and external surfaces of the external barrier structure is determined
from Tables 5 and 6 of QMQ 02.01.04-97*.
α
i
and α
t
Vt/ m
2
∙ ℃
.
3. The total heat transfer resistance of the external wall is determined.
The total heat transfer resistance of the external barrier structure consists of three types of
resistance:
1) The resistance to the transfer of heat from the internal air to the internal surface of
the structure. This heat transfer resistance is called (
�
�
) and is due to the difference between
the internal air temperature and the internal surface temperature of the structure, and this
difference is written as
�
�
− �
�
.
2) The resistance to the passage of heat through the div of the structure. This is
called the thermal resistance (R) of the structure and is the difference between the
temperature of the inner surface of the structure and the temperature of the outer surface, i.e.
�
�
− �
�
;
3) The resistance to the transfer of heat from the outer surface of the structure to the
outside air. This heat transfer resistance is called (
�
t
) and is caused by the difference between
the temperature of the outer surface of the structure and the outside air temperature, i.e.
�
�
−
�
�
.
Therefore, the total heat transfer resistance of the external barrier structure is the sum
of three different resistances:
R
y
= R
i
+ R + R
m
(1.3)
The resistances to heat absorption and release are often expressed in the same way and are
called the heat transfer resistance of the internal and external surfaces of the structure.
The inverse value of the heat transfer resistance is called the heat transfer coefficient.
The heat transfer coefficient of the internal surface of the structure is denoted by
и
and is
found from the following expression:
�
и
=
�
�
и
(�. �)
The heat transfer coefficient of the
external surface of the structure is represented by
�
т
and is found from the following formula:
�
т
=
�
�
Т
(�. �)
The transfer of heat from the inner
INTERNATIONAL JOURNAL OF ARTIFICIAL INTELLIGENCE
ISSN: 2692-5206, Impact Factor: 12,23
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Journal:
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surface of the structure to the air or from the outer surface occurs through thermal radiation
and convection.
Therefore, the heat transfer coefficient is
equal to the sum of the heat transfer coefficients by thermal radiation and convection.
� = �
и
+ �
к
; (�. �)
Heat is transferred to the inner surface of the external barrier structure by radiation
from the inner walls, ceiling, and floor surfaces of the room, since their temperature is always
higher than the temperature of the inner surface of the external barrier structure. The outer
surface of the external barrier structure, in turn, gives off heat to the external environment (air)
by radiation.
The coefficient of heat transfer by thermal radiation is determined by the following
formula:
2
1
4
2
4
1
0
2
1
н
t
t
100
273
t
100
273
t
С
1
С
1
С
1
1
-
+
-
+
-
+
=
(1.7)
where, C
1
and C
2
- are the radiation coefficients of the surfaces;
S
0
- the emissivity of a black div;
t
1
, t
2
- the temperature of the surfaces.
For all buildings, the thermal resistance and heat transfer coefficients of the internal
and external surfaces of external enclosing structures are given in QMQ – 2.01.04-97*.
The thermal resistance (R) of external enclosing structures depends on the
composition of the material from which the structure is made and the coefficient of thermal
conductivity.
If the external wall consists of several layers, its thermal resistance is equal to the sum
of the heat transfer resistances of the layers. Therefore, the thermal resistance of multi-layer
structures is determined by the following formula
� = �
�
+ �
�
+ … + �
�
=
�
�
�
�
+
�
�
�
�
+ . . . +
�
�
�
�
�. �
where,
�
�
, �
�
, �
�
- heat transfer resistance of individual layers,
�
�
∙ ℃/��
;
�
�
,
�
�
va
�
�
– thickness of individual layers, m.
�
�
,
�
�
va
�
�
– thermal conductivity coefficient of individual layers,
��/�
�
∙ ℃;
n – number of layers that make up the structure.
The thermal resistance
�
�
of external enclosing structures must not be lower than the
values
�
�
тр
indicated in Tables 2a, 2b or 2c, depending on the given level of thermal
protection of the building.
List of used literature:
1. Shukurov Gʼ.Sh., Boboev S.M. Аrxitektura fizikasi. 1-qism. Qurilish
issiqlik-
fizikasi.Darslik – T.: Mehnat, 2005 y. 160s.
INTERNATIONAL JOURNAL OF ARTIFICIAL INTELLIGENCE
ISSN: 2692-5206, Impact Factor: 12,23
American Academic publishers, volume 05, issue 05,2025
Journal:
https://www.academicpublishers.org/journals/index.php/ijai
page 260
2. Shukurov Gʼ.Sh., Islomova D. Gʼ. Qurilish fizikasi. Darslik – Samarqand. 2015 y.226s.
3. Fokin. K.F. Stroitelьnaya teplotexnika ograjdayuщix chastey zdaniy.
M. Stroyizdat,
1973g. 286s.
4. QMQ-2.01.04-18. Stroitelьnaya teplotexnika. – T., 2018 y.
5. Shukurov Gʼ., Neʼmatov B. Mayda blokdan iborat tashqi devor
konstruktsiyasini
issiqlik himosini oshirish. Obrazovanie nauka i
innovatsionnыe idei v mire.
Mejdunarodnыy nauchnыy elektronnыy
jurnal. Rossiya-2023 y.
http:/www.neviournal.org/
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M. A. (2024, July). Innovative solutions for the use of aerated concrete blocks in
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FOYDALANISHNING
INNOVATSION
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(SCIENTIFIC
TECHNICAL
JOURNAL), 1(2), 251-254.
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