CLASSIFICATION OF VENTILATION SYSTEMS

The main purpose of ventilation - maintaining acceptable air parameters in the room - can be achieved in various ways. The methods for supplying and removing air can be very different.

A ventilation system is a set of devices for processing, transporting, supplying and removing air.

Ventilation systems can be classified according to the following criteria.

1. As intended They are divided into supply and exhaust. Supply ventilation systems supply air into the room, and exhaust systems remove polluted air from the room.

2. According to the method of organizing air exchange in the room There are general, local, combined and emergency ventilation systems.

General ventilation system used to create identical air parameters (temperature tb, relative humidity, air mobility Vb) throughout the entire volume of the room or in work area( = 1.5-2 m from the floor) in the presence of dispersed sources of harmful emissions.

Local ventilation system creates local air conditions that meet sanitary and hygienic requirements, different from the conditions in the rest of the room. Local systems ventilation can be exhaust or supply. With the help of local exhaust ventilation systems (suction), polluted air is removed outside the premises directly from the source of the hazard. They can be with mechanical exhaust or natural. Examples of local exhaust ventilation systems are fume hoods, simple umbrellas, canopy umbrellas, side exhausts, exhaust panels, casings, etc.

Local supply ventilation systems supply air to any specific part of the room. An example is air showering. In this case, the air stream is directed directly at workplace, or air curtains, with the help of which they prevent the passage of air through an open opening. Local ventilation systems are compact and require less air consumption.

On modern industrial enterprises apply combined ventilation systems – they represent various combinations of general ventilation with local ventilation.

Emergency ventilation system is provided in rooms where sudden release of harmful substances in quantities significantly exceeding the maximum permissible concentrations. Emergency hood is always mechanical. As a rule, axial fans are used, located in wall openings without air ducts. Centrifugal fans can also be used, with the help of which contaminated air is removed through special channels. In most cases, emergency ventilation is switched on automatically.

3. By the method of stimulating air movement Ventilation systems are divided into mechanical and natural.

Mechanical ventilation systems supply and remove air from the room using a fan or ejector. The air supplied to the room can be specially treated, i.e. can be heated, cooled, dried, cleared of dust.

In natural ventilation systems Oh(gravitational) air movement is carried out due to pressure caused by the difference in densities of internal and external air, as well as due to wind pressure. Natural ventilation happens unorganized And organized . Unorganized ventilation occurs through leaks in building structures, as well as when opening windows and doors. With organized natural ventilation air exchange occurs through transoms specially installed in the external enclosures, the degree of opening of which is regulated on each side of the building (aeration) or through specially constructed channels.

4. By device Ventilation systems are divided into ducted and non-ducted. IN duct systems Air supply and removal is carried out through an extensive network of channels (air ducts). Duct and non-duct ventilation systems can be either mechanical or natural. An example of a ductless ventilation system is air showering using recirculation, aeration of an industrial building.

Depending on the type of harmful secretions, they are used various schemes air exchange.

The following designations are used in the diagrams:

PC – supply room;

N, P, U – external, supply and exhaust air, respectively;

VU – exhaust unit;

1) Exhaust duct ventilation. (Fig. 3.1.)

Rice. 3.1. Exhaust system ventilation.

Exhaust ventilation can be natural or mechanical. In residential buildings, exhaust ventilation is organized in bathrooms, bathrooms, kitchens, garbage collection chambers, and electrical panels. IN public buildings exhaust ventilation is provided from storerooms, smoking rooms, dressing rooms and other auxiliary rooms from which the spread of harmful substances and odors is undesirable.

2) Supply duct ventilation. (Fig. 3.2.)

Rice. 3.2. Supply ventilation system.

Mechanical supply ventilation is most often used. This arrangement of air exchange is used in lobbies and cinema foyers.

3) Supply and exhaust direct-flow ventilation. (Fig. 3.3.)

Rice. 3.3. Supply and exhaust ventilation system.

It is used in most areas of public buildings, as well as in industrial premises where the use of recycling is prohibited. Extraction can be natural or mechanical. Heat consumption for heating supply air maximum

4) Supply- exhaust ventilation with partial recirculation (Fig. 3.4.)

Rice. 3.4. Supply and exhaust ventilation system with partial recirculation.

K1 and K2 are valves that regulate the amount of recirculation air.

To save heat in cold period Recirculation is used to heat the supply air. Recirculation is the mixing of exhaust air with supply air. Air mixing can occur before the supply chamber (scheme with I recirculation) and after the supply chamber (scheme with II recirculation); schemes with I and II recirculation are used simultaneously. Partial recycling is used in conventional systems ventilation during working hours. The minimum amount of supply air must be no less than the sanitary standard.

5) Supply and exhaust system with full recirculation. (Fig. 3.5.)

Rice. 3.5. Supply and exhaust system with full recirculation.

The use of such a ventilation system during non-working hours will significantly reduce the heat consumption for heating the air.

6) Supply and exhaust general exchange natural ductless ventilation. (Fig. 3.6.)

Rice. 3.6. Supply and exhaust general exchange ductless natural system ventilation.

1 – heat source.

An example of such ventilation is the aeration of industrial buildings. Aeration is an organized natural air exchange, which is carried out through specially provided adjustable openings in external fences under the influence of gravitational forces and wind energy.

7) Supply local ductless ventilation.

Mechanical forced local ventilation can be implemented using ventilation units operating on the internal air of the room. These systems are used for showering workplaces. Supply local ductless ventilation with natural impulse is rarely used. Air is supplied through specially provided openings in the external enclosures.

8) Direct-flow supply and exhaust system with general exchange inflow and local exhaust. (Fig. 3.7.)

Rice. 3.7. Direct-flow supply and exhaust ventilation system with general exchange inflow and local exhaust.

It is used in industrial premises in which the performance of local suction is sufficient to remove all harmful substances and, according to design standards, additional general exhaust hood is not required.

9) Supply and exhaust system with local inflow and general exchange exhaust. (Fig. 3. 8.)

Rice. 3. 8. Supply and exhaust system with local inflow and general exchange exhaust.

Such systems are used in rooms in which the amount of supply air supplied by local supply ventilation systems is sufficient to dilute harmful substances to maximum permissible concentrations. As a local air supply unit, air showering of workplaces with outside air can be used, or, in small rooms, permanent air curtains.

10) Combined ventilation systems. (Fig. 3.9. and 3.10.)

Rice. 3. 9. Direct-flow supply and exhaust ventilation system with general exchange inflow and exhaust and local suction.

The ventilation system shown in Fig. 3. 9. is used in industrial and public buildings in cases where it is impossible to remove all harmful substances from the premises using local suction U2.

Such systems can be implemented in the hot shop of a restaurant, in laboratories, in galvanizing, painting shops, etc.

Rice. 3.10. Direct-flow supply and exhaust ventilation system with general inflow and exhaust and local inflow.

The ventilation system shown in Fig. 3. 10. used in hot shops, where work areas are provided with outdoor air, but clean air is not enough to dilute all the harmful substances released in the room or in rooms with working air curtain, which prevents cold air from rushing in through the open opening.

11) Split ventilation systems.

These systems remove excess heat using a refrigeration machine, consisting of two units: external and internal. Mounted externally: refrigeration machine, capacitor and fan air cooling. In the internal one there is an evaporator and a fan that circulates air through the evaporator. The supply of sanitary air standards is ensured either by a special device supply and exhaust system ventilation, or the use of partial recirculation. (Fig. 3.11.)

Rice. 3. 11. Split ventilation systems.

a) split ventilation system with supply and exhaust unit;

b) Split ventilation system with partial recirculation of supply air.

I – evaporator;

Types of ventilation are represented by a wide variety of systems of various types and purposes. Systems are divided into several types based on common characteristics. The main ones are the methods of air circulation in the building, the service area of ​​the unit, and the design features of the product.

Natural way of air exchange

Looking at Types ventilation devices, you should start with this type. In this case, air movement occurs for three reasons. The first factor is aeration, that is, the temperature difference between indoor and outdoor air. In the second case, air exchange is carried out as a result of wind pressure. And in the third case, the pressure difference between the room used and the exhaust device also leads to air exchange.

The aeration method is used in places with high heat generation, but only when the incoming air contains no more than 30% of harmful impurities and gases.

This method is not used in cases where the incoming air needs to be treated or the influx of outside air leads to condensation.

In ventilation systems, where the basis for air movement is the pressure difference between the room and the exhaust device, the minimum height difference should be at least 3 m.

In this case, the length of horizontal sections should not exceed 3 m, while the air speed is 1 m/s.

These systems do not require expensive equipment; in this case, hoods located in bathrooms and kitchen areas. The ventilation system is durable and does not require purchasing additional devices to use it. Natural ventilation is easy and cheap to operate, but only if it is set up correctly.

However, such a system is vulnerable, since it is necessary to create additional conditions for the flow of air. For this purpose, pruning interior doors so that they do not interfere with air circulation. In addition, there is a dependence on the air flow that blows through the building. The natural ventilation system depends on it.

An example of this type is open window. But with this action or installation of hoods, another problem arises - a large amount of noise coming from the street. Therefore, despite its simplicity and efficiency, the system is vulnerable to a number of factors.

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Means for artificial air exchange

An artificial system, also known as a mechanical one, uses additional devices for ventilation that help air enter and leave the building, thereby organizing a constant exchange. For this purpose, a variety of devices are used: fans, electric motors, air heaters.

The big disadvantage of operating such systems is energy costs, which can reach considerable values. But this type has more advantages; they fully cover the cost of using the funds.

The positive aspects include the movement of air masses to the required distance. Besides, similar systems ventilation can be adjusted, so air can be supplied or removed from rooms in the required quantity.

Artificial air exchange does not depend on environmental factors, as is observed with natural ventilation. The system is autonomous and can be used during operation additional functions, for example, heating or humidifying the incoming air. With a natural type, this is impossible.

However, it is currently popular to use both air supply systems at once. This allows you to create the necessary conditions indoors, reduce costs, increase the efficiency of ventilation in general.

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Supply air supply method

This type of ventilation system is used to provide a constant supply of fresh air. The system can prepare air masses before they enter the apartment. For this purpose, air purification, heating or cooling is carried out. Thus, the air acquires necessary qualities, after which it enters the room.

The system includes air supply units and air vents, and the installation that provides air supply, in turn, includes a filter, air heaters, a fan, automatic systems and sound insulation.

When choosing such devices, you should pay attention to a number of factors. The volume of air entering the building is of great importance. This figure may be several tens or several tens of thousands cubic meters air entering the room.

Indicators such as heater power, air pressure and noise level of the device play a big role. In addition, these types of ventilation devices have automatic regulation, which allows you to regulate power consumption and set the level of air consumption. Devices with timers allow you to set the unit to operate on a schedule.

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Combination of two methods: supply and exhaust type

This system is a combination of two ventilation methods - supply and exhaust, which allows you to use positive traits both systems simultaneously and leads to improved air exchange.

As in the previous version, there is a means of filtering and regulating incoming air masses. This type can create the necessary conditions in the room, regulate the level of humidity of incoming masses, create desired temperature, heating or cooling the air. Filtering air masses coming from outside is also included in functionality unit.

A supply and exhaust system will help reduce costs, which is achieved by removing heat that is used to heat the incoming air. This process takes place in a recuperator - a special-purpose heat exchanger.

Exhaust air masses at room temperature enter the device, after which they transfer their temperature to the recuperator, which heats the air coming from outside.

In addition to the above advantages supply and exhaust ventilation has another quality that is well suited for people suffering from changes blood pressure. It's about about the possibility of creating increased and decreased pressure compared to the environment.

The device is autonomous, independent of conditions environment, thanks to which it can be used all year round. However, the system is not without negative qualities. Among them is the need for precise adjustment. If both methods - exhaust and supply - are not balanced with each other, then a person using this type of ventilation runs the risk of getting drafts in the house.

Introduction. 3

1. The concept of methods for organizing air exchange and the design of ventilation systems. 4

2. Types of ventilation. 6

3. Ventilation equipment . 12

Conclusion. 16

References.. 17

Introduction

For human life great importance has air quality. The well-being, performance, and ultimately health of a person depends on it. Air quality is determined by its chemical composition, physical properties, as well as the presence of foreign particles in it. Modern conditions human life requires effective artificial means of improving the air environment. Ventilation technology serves this purpose.
In general, ventilation (from Latin ventilatio - airing), according to generally accepted definition, called controlled air exchange in the room, as well as the devices that create it. The purpose of ventilation is to maintain chemical and physical condition air that meets hygienic requirements, i.e. ensuring certain meteorological parameters of the air environment and air purity. Factors whose harmful effects can be eliminated with the help of ventilation include: excess heat (convection, causing an increase in air temperature, and radiant); excess water vapor - moisture; gases and vapors of chemical substances with generally toxic or irritating effects; toxic and non-toxic dust; radioactive substances.

The concept of methods for organizing air exchange and the design of ventilation systems.

Satisfying indoor air environment sanitary standards is ensured by removing polluted air from the room and supplying clean outdoor air. Accordingly, ventilation systems are divided into exhaust and supply.

Based on the method of moving the air removed from the premises and supplied to the premises, a distinction is made between natural (unorganized and organized) and mechanical (artificial) ventilation.

Unorganized natural ventilation refers to the air exchange in rooms that occurs under the influence of the difference between external and internal air and the action of air through enclosing structures, as well as when opening vents, transoms and doors. Air exchange, which also occurs under the influence of the difference in pressure of the external and internal air and the action of the wind, through transoms specially arranged in the external fences, the degree of opening of which is regulated on each side of the building, is natural, but organized ventilation. This type of ventilation is called aeration.

Mechanical, or artificial, ventilation is the method of supplying air to or removing air from a room using a fan. This method of air exchange is more advanced, since the air supplied to the room can be specially prepared in terms of its purity, temperature and humidity.

Mechanical ventilation systems that automatically maintain meteorological conditions in rooms at the level specified, regardless of changing parameters of the external air environment, are called air conditioning systems (condition).

According to the method of organizing air exchange in rooms, ventilation can be general, local, localizing, mixed and emergency.

General ventilation, called general exchange, provides for the creation of identical air conditions (temperature, humidity, air purity and air mobility) throughout the entire room, mainly in the work area (# = 1.5-2 m from the floor) (Fig. PY ,A).

Local ventilation creates local (at workplaces) air conditions that meet hygienic requirements, different from the conditions in the rest of the premises. An example of a local supply ventilation An air shower can serve as a jet of air directed directly at the workplace (Fig. Ш.1, b).

The principle of operation of localized ventilation is to capture harmful emissions directly from production plants using special shelters that prevent the entry of harmful emissions into the room.

Mixed systems, used mainly in industrial premises, are combinations of general ventilation with local ventilation (Fig. Ш.1, c).

“Emergency” ventilation units are installed in rooms in which there may be a sudden unexpected release of harmful substances in quantities significantly exceeding the permissible ones. This setting is turned on only if it is necessary to quickly remove harmful emissions.

The question of which of the listed ventilation systems should be installed is decided in each individual case, depending on the purpose of the room, the nature of the harmful emissions arising in it, and the traffic pattern air flow inside the building.

In the so-called hot shops, aeration, local suction and air showers are widely used. Air thermal curtains are installed at the gates. In cold shops, general supply and exhaust ventilation and air conditioning systems are used where this is dictated by the technology conditions. In public buildings (theaters, cinemas, meeting rooms, shops, gyms, etc.), as a rule, a general supply and exhaust system is installed ventilation or air conditioning system.

In rooms where little air exchange is required, only one exhaust ventilation is provided. The amount of air removed in this case is replenished by air entering the room through leaks in the enclosing structures and when opening vents or transoms.

In residential buildings, only exhaust (natural, rarely mechanical) ventilation from kitchens and bathrooms is usually installed. The flow into living rooms is carried out through windows, vents or special devices under the windows.

Types of ventilation

Types of ventilation are represented by a wide variety of systems of various types and purposes. Systems are divided into several types based on common characteristics. The main ones are the methods of air circulation in the building, the service area of ​​the unit, purpose of ventilation and design features of the product.

The principle of supply and exhaust ventilation in a private house.

How does air exchange occur in residential premises?

natural ventilation
air permeability of enclosing structures

Imagine a room, say 12 m2, 32 m3. There is a door in the room, but it is good and closed, the walls are ordinary, panel or brick, possibly wooden. There are no cracks in the walls, the windows are good and adjusted. There is one person in the room.

If the windows are closed, then air exchange is carried out through external, and possibly internal, enclosing structures (walls, ceilings). If the walls are wooden or thin, then the air exchange is greater, if the walls are concrete and thick, then less. This air exchange may be enough, that is, the concentration of, say, carbon dioxide may not go beyond acceptable limits.

If there are more emissions, for example, five people in the same room, then the concentration at any walls will certainly be significantly higher than the normative one.

window

If you open or slightly open a window in a conventional room, then even if there is no wind, the air exchange will be large; usually in the upper part of the open opening the air will go outside, and along the lower part - into the room. The air will change quickly, but if it is winter outside, it will be very cold. Even if the window is slightly open, since the height of the opening is large, the air exchange will be large.

If you increase the heating power accordingly, then when ventilating through the entire window it is still difficult to avoid drafts - flows of supercooled air compared to the surrounding air. Ventilation by opening the entire window is only suitable for periodic ventilation.

windows

The difference between a window and a window is that its height is less than that of a window, therefore, both with full and partial opening, the air exchange is much less. Falling cold air may have time to heat up. The window can provide normal air exchange; it can be adjusted within certain limits.

But if the air temperature inside and outside our conditional room is the same, and there is no wind, then the air exchange will most likely be less than necessary.

vents and ventilation ducts in the back of the room

This is a standard scheme, known in practice to almost everyone. A warm channel in the back of the room (bathroom, kitchen) provides exhaust, and an influx enters through the window.

Theoretically, it should always work, in practice it often does not work on the upper floors, it requires a constant small inflow, when installing dense windows, the “light” inflow stops, the air permeability of the walls remains, it can be very small. Requires open or loose, trimmed doors.

supply valves

Various types work in this scheme supply valves, “Euro-windows”, etc. These are complicated vents with increased resistance.

If there is good air exchange in the room of the type under consideration (duct-window), then replacing the window with a valve is possible, and most likely the air exchange will decrease.

If the air exchange with the window is bad, then with the valve it will become even worse, i.e. replacement is not recommended.

natural exhaust ventilation

Our conditional room has good doors, so it needs its own channel to implement this type of ventilation. If this channel is in every room, if it is made correctly, then in most cases normal air exchange is ensured in rooms with an open window.

natural supply and exhaust ventilation

But open window– this is a road for noise and some other inconveniences.

The inflow during natural ventilation can also be ducted. If everything is done correctly, then this is what happens. better ventilation. The flow rate depends on the design of the channels, and can be higher if required. So we think that the consumption is normal. The noise does not go away, or very little goes through.

When moving along the channel, some heating, cooling, cleaning, etc. can be organized, but all this is only in small quantities, since the pressure drop is driving force natural ventilation is very small.

So there is only one drawback: very limited opportunity air treatment.

Air exchange is called partial or complete replacement air containing harmful emissions with clean air. The amount of air related to its internal cubic capacity is usually called the air exchange rate. In this case, + denotes air exchange along the inflow, - air exchange through the exhaust. So, if they say that the air exchange rate is, for example, +2 and -3, then this means that in 1 hour twice the amount of air is supplied to this room and three times the volume of the room is released from it.

Air exchange in the premises is determined separately for the warm and cold periods of the year and transitional conditions at a density of supply and exhaust air of 1.2 kg/m3
a) by excess sensible heat

b) by the mass of released harmful substances

If several harmful substances that have a cumulative effect are released into the room, it is necessary to determine the air exchange by summing the air flow rates calculated for each of these substances; : ,

c) by excess moisture (water vapor)

In rooms with excess moisture(theaters, canteens, baths, laundries, etc.) it is necessary to check the sufficiency of air exchange to prevent the formation of condensation on inner surface external fences at calculated parameters of outdoor air during the cold season;

d) by excess total heat

e) according to the normalized air exchange rate

e) according to the standardized specific consumption supply air

The largest of the values ​​obtained from the given formulas should be taken as the calculated value of air exchange.

Air humidity is not the same across the height of the room. She shrinks into him upper layers due to the increase in air temperature as it approaches the ceiling. Air humidity in a room with natural circulation is determined by the following reasons:

1) the release of moisture by people and indoor plants(increases with the number of people in the room);

2) the release of moisture during cooking, washing and drying clothes, washing floors, etc. In this case, the release of moisture can be so significant that it causes a sharp increase in air humidity compared to normal;

3) production conditions, that is, the release of moisture during a particular production process;

4) humidity of enclosing structures. Usually in the first year after the completion of construction of brick buildings, when the evaporation of construction moisture from the inner surface of the fence increases the humidity of the internal air. In these buildings, in the first year of operation, the relative air humidity reaches 70-75%, so in the first winter you should pay attention to increased ventilation of the building.

End of work -

This topic belongs to the section:

Theoretical foundations for creating an indoor microclimate

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IN winter time outside air has a higher density (due to low temperature) than indoor air (with more high temperature). Once

Wind pressure
Under the influence of wind, on the windward sides of the building (see figure) a overpressure, and on the leeward sides - rarefaction. The amount of excess static pressure (wind)

Air permeability of fences
The air permeability of fences does not always correspond to the air permeability of their materials. The air permeability of the enclosing structure is assessed by the value of the air permeation resistance:

Definition and application of air
Air is a natural mixture of gases, mainly nitrogen and oxygen, that forms the earth's atmosphere. Air is necessary for the normal existence of the vast majority of terrestrial living organisms:

Air condition and composition
Humid air is a vapor-gas mixture consisting of dry air and water vapor. Knowledge of its properties is necessary for a civil engineer to understand and calculate such technical devices, How

Determination of air characteristics
The main characteristics of humid air include: - Absolute humidity D, which determines the mass of water vapor (moisture) contained in 1 m3 of humid air.

Means and methods for controlling air humidity
To determine air humidity, instruments called psychrometers are used (in which the temperatures of “dry” and “wet” thermometers are simultaneously measured, the difference between which determines

The value of the air humidity parameter as an environmental indicator of the environment
Relative air humidity is an important environmental indicator of the environment. If the humidity is too low or too high, a person becomes fatigued quickly, and perception and memory deteriorate. IN

I-d diagram of humid air
Issues related to humid air (definition by parameter, construction of processes) can be resolved using the i-d diagram proposed in 1918 by Professor L.K. Ramzin.

The principle of determining air parameters using the i-d diagram
Using the i-d diagram, you can determine the temperature of the dew point (at the intersection with the line φ = const line d = const coming from the point characterizing the initial state of the air) and the temperature of the “wet

The essence of the aspiration method for determining relative humidity
The essence of the aspiration method for determining relative humidity is as follows (Figure 3.13). Ri

Thermophysical properties of dry air
under normal conditions atmospheric pressure* t, °C r, kg/m3 cp, kJ/kg/K

Reasons for the appearance of moisture in external fences
The following types of moisture may be present in the building envelopes: - construction moisture - introduced during the construction of buildings or during the manufacture of prefabricated reinforced concrete structures;

Humidity characteristics of indoor and outdoor air
Moisture (in the form of water vapor) contained in atmospheric air determines its moisture content. The amount of moisture contained in 1 m3 of air expresses its absolute humidity. D

Moisture condensation on the surface of the fence
If you cool any surface in air with a given humidity, then when the temperature of this surface drops below the dew point, the air in contact with it will condense water during cooling

Measures against moisture condensation on the surface of the fence
The main measure against moisture condensation on the inner surface of the fence is to reduce the air humidity in the room, which can be achieved by increasing its ventilation. Avoided

Sorption and desorption
The concept of sorption covers two phenomena of absorption of water vapor by a material: 1) absorption of vapor by the surface of its pores as a result of the collision of steam molecules with the surface of the pores and, as it were, sticking

The physical essence of vapor permeability
The absence of moisture condensation on the inner surface does not guarantee protection from moisture, since it can occur due to sorption and condensation of water vapor in the thickness of the fence itself

Quantitative dependencies for calculating vapor permeability
By analogy with the formula for heat transfer by thermal conductivity through a flat wall under stationary conditions, presented as a dependence of the surface heat flux density (specific)

Features of calculating humidity conditions
To calculate the humidity conditions of external fences for humidification with vaporous moisture, it is necessary to know the temperature and humidity of the internal and external air. Temperature and humidity internally

Method for calculating humidity conditions
The method for calculating the humidity regime in the fence (in order to check the absence of condensation and accumulation of moisture in it) is performed as follows. To construct the elasticity drop line in

Factors influencing the humidity regime of the fence
To prevent moisture condensation on the inner surface of the outer fence, it is necessary that the dew point temperature

Analysis of conditions for drying of the fence
The presented method for calculating the humidity regime of external fences makes it possible to calculate the rate of subsequent drying of the fence after the condensation of water vapor in it has stopped, namely

Evaluation of the results of calculating the humidity regime
Calculation of the humidity regime under stationary conditions is simple and can give a fairly accurate answer to the following two questions: - will protection from moisture condensation be guaranteed?

Calculation of humidity conditions under non-stationary conditions of water vapor diffusion
The stated calculation of the humidity regime of fences under stationary conditions of water vapor diffusion does not take into account changes in the humidity of materials in the fence over time, as well as the influence of the initial humidity

Measures against condensation in enclosures
The main constructive measure to ensure protection from moisture condensation in it is the rational arrangement of layers of various materials in the fence. To warn you

Humidity regime of attic floors
Big influence The moisture regime of roofless coverings is influenced by a waterproofing carpet, the purpose of which is to protect the covering from wetting it with rain or melt water. Waterproofing

Mechanism of moisture movement
The movement of moisture in a material begins from the moment condensation moisture is formed in it, since sorbed moisture, which is in a bound state in the material, does not move in liquid form.

Conditions for the movement of moisture in building materials
To allow capillary movement of moisture in a material, a moisture gradient is necessary, i.e., a change in the moisture content of the material in the direction of moisture movement in it. In this case, the moisture in the material will be

Sanitary and hygienic fundamentals of microclimate conditioning systems
Modern human living conditions require effective artificial means of improving the air environment (using heating, ventilation and air conditioning techniques). With heating

The concept of methods for organizing air exchange and the design of ventilation systems
An airy indoor environment that meets sanitary standards is ensured by removing polluted air from the room and supplying clean outdoor air. According to this system

Air distribution by jets
A jet is a flow of liquid or gas with finite transverse dimensions (Fig. 9.2). Ventilation technology deals with streams of air flowing into a room filled with air. So

General remarks
Buildings (as a complex architectural and structural system) are characterized by a thermal regime determined by heat absorption processes of different physical nature. Under the influence of various

Purpose of indoor climate control systems
The required indoor microclimate is created by the following building engineering equipment systems: heating, ventilation and air conditioning. Heating systems are designed to create

Types and scope of heating systems
The heating system of residential buildings must ensure uniform maintenance of the design temperatures of heated premises throughout the entire heating season, as well as: the ability to regulate heat

Energy saving and indoor microclimate
Energy costs are the main expense item associated with the operation of a home; in addition, energy prices continue to rise steadily, and along with this, maintenance costs are also increasing.