Calculation of the supply installation. Features and procedure for calculating exhaust and supply ventilation

Tambour is a small room at the entrance to the house, which serves as a thermal gateway between the house and the street. Entering into the house, a person sequentially opens and closes the door first from the street, and then the door from the tambura to the house.

Thus, between the house and the street always remains at least one closed door. Tambour protects the inner space of the house from the penetration from the street of the wind, damp, cold in winter, and heat in the summer.

The presence of a tambura reduces the amount of heat that leaves the house in winter at an open entrance door. Heat losses with flowing from the tambour air will be minimalIf the tambour does not heal and is not too much volume.

For the construction rules, the thermal gateway is a tambura device, be sure to in an apartmently residential building located in areas with a temperate and cold climate.

For a private house, the presence of Tambura is not a mandatory requirement of the rules.

In private houses, as a rule, refuse the standard small tambour device.The room at the entrance to the house architects increase in size, add new features to it, or at all cost without a tambura.

Standard tambour built in the thermal contour of the private house. Square Tambura 2,1 m 2.. The normative depth of the tambour is not less than 1.2 m..

Many architects and developers came to understand that to arrange a small closer camork at the entrance to a private house, Only for the sake of saving heat, is not profitable. Look modern planning Private houses, for example, Scandinavian architects - there is no Tambura in the house.

Russian architects often do not see the difference between the thermal gateway in an apartment and private house. In projects, in the other case, the close chambers of the minimum sizes are drawn at the inlet. Probably affects the lack of experience in a private house.

In the house without a tambura, the intake of cold air, the wind is limited at the expense of various architectural techniques. For example - placed the porch and the entrance door in the recess, in the niche.

Look at the drawing and imagine. You open the front door and get out of a small snack of a tambura or even a hallway. And before your gaze, the magnificence of the design of the spacious hall with a further prospect of the dining room and living room opens. It is so modern, fashionable and great!

Now imagine another picture. The front door and frosty air clubs open from the street will be flying deep into the house. In the summer, the wind pokes into an open door and spreads the heat, dust and allergenic pollen of the plants around the house with air conditioning. From the door in the lobby, which leads to the garage, the sounds and smells of the working motor.

Which of the two pictures in the house without a tambura you impressed more?

IN russian tradition In front of the entrance to the residential part of the house, quite large sense were always suitable. Seni is a thermal gateway, who protects the house from the air of the street as well connects the living part of the house with household buildingslocated in the same amount with the house.

If household buildings do not adjoin the house, then the walls are made glazed, and such a room at the entrance to the house is called the veranda.

In the northern snowy areas in Seine often place a staircase, on which they rise to the level of the first floor. Maybe more than 1 m.. In the southern regions, this is more often made by a high porch with steps outside the house.

Of course, and in the north you can make a high porch and outside the steps, but with an electric heating. Otherwise, the steps of the porch in the winter are iced, and will provide a permanent owner headache And the alarm for the health of loved ones.

In previous times, the farm was kept the cattle, cultivated land, many children raised. To the house it was necessary to bring firewood, water, facilities on the street. The entrance door in such a house from morning to evening almost did not close. The thermal gateway in such a house is certainly necessary.

Modern life in a private house is often completely different. Modern entrance doors, not as example, sealed and well insulated. Another way of life in a private house, new designs and technologies in the home apparatus, allow you to do without a tambura at the entrance.

Does it need in a private house tambour?

Tambour can:

• Protect the house from penetration through the entrance door of the cold, heat, dust, pollen plants.
• Being a buffer room between the residential and economic parts of the house, providing convenient movement, and, at the same time, the protection of residential premises from pollution and noise of economic.
• Become a hallway, where you can remove and store upper clothes and shoes.
• Serve as the placement of the stairs at the entrance to the house for lifting to the level of the first floor.

Sizes, Tambour depth

According to the construction rules, the standard vestibule in the house must have a depth of at least 1.2 m.. For the use of the room was comfortable to envisage at least small window Or the front door with glass.

According to the rules of fire safety in apartment houses And public buildings both doors in the vestibule should open outwards towards the street. For private homes, this requirement is not necessary.

In the usual tambone they do not make heating.

Device input tambour in a modern private house

Tambour - parishion

The entrance tambour is beneficial to combine with the hallway. The room includes the installation of cabinets for storing the outerwear and shoes, a place to dress up.

Tambour - an entrance hall is equipped with cabinets for storing the outerwear and shoes. Dress up left. To protect the premises of the house from the air of the street, the hallway is separated from the rest of the house at the door in the hall. The wall of the wall creates a "quiet zone" porch, protected from wind.

Tambour - the hallway is equipped with heating. Be sure to install the window.

To the entrance hall performed the functions of the heat gateway, be sure to install the door Between the hallway and the rest of the premises in the house.

To eliminate dampness and smells, in the hallway-tambour need to be done. Ventilation reduces indoor air humidity, which reduces the risk of condensate formation on the details of the entrance door from the street.

Tambour - Seni.

If under one roof with the house there is a garage, boiler room or other shopping facilities, it is convenient to make a tambour with a buffer room through which there are moving people between residential and business parts of the house.

Tambour - Seni (urban version), connects the living part of the house with economic premises. The porch is located between the walls of the house and the garage in the place protected from the wind. In areas with snowy winters, the ladder for lifting to the level of the first floor is beneficial to accommodate in Seine.

Agree, it is comfortable to move from one part of the house to another without leaving the street. From the economic premises you can immediately, without entering the house, through the tambour to go out.

At the same time, such a tambour protects the living part of the house not only from the air of the street, but also from smells and sounds from economic premises.

So that the smells do not get through the vestibule into the house, economic premises necessarily equip the system of exhaust ventilation.

Such a vestibule should not be missed if you want to save heat. But the window should be provided.

Tambour - Veranda

The thermal gateway at the entrance to the house can be closed, glazed veranda. The veranda is usually arranged in the house when economic buildings are located in the distance from the house.

Tambour - a veranda with glazed walls. In areas with snowy winter, the staircase at the entrance to the lifting to the level of the first floor is beneficial to place inside the veranda.

Here the tambour is outside the thermal shell of the house. In areas with a cold climate, it is recommended to warm the walls of Tambura-veranda well, and for glazing to use double glazing.

To improve heat shields, walls of tambura veranda often make wall materials and reduce the glazing area. The pre-home to the house of the veranda, as well as the Songs, reduce heat loss through the wall of the house.

Heating on the veranda is not necessary.

Device Porch at the entrance to the private house

Outside, in front of the entrance door to the house. Suit the porch. The porch is necessary to protect the entrance door from precipitation.

Moreover, porch creates comfortable conditions for manwho is preparing to enter the house. On the porch you can safely put the bags, fold the umbrella, clean your legs about the rug, get the keys or wait until the door is open.

To perform the specified tasks, the porch must have a roof. The man on the porch feels more comfortable if he is also protected from the wind.

In the house without Tambura, the porch design is chosen so as to limit the movement of cold air to the house. For this porch necessarily protect against wind.

The porch is arranged on a platform, which is raised over the ground on the plot. In this case, the surface of the porch is always dry. The surface of the porch is recommended to raise with a minimum of one step at a minimum - at 20 cm. By the way, the minimum height of the base of the private house is also equal to 20 cm.

House with a tambour - a veranda. Not successful design - The high narrow porch is open to all winds, rains and blizzards. The porch will constantly worst, beyond and collapse from frost. Poor protects the front door from precipitation. A man on such a porch is uncomfortable.

The height of the private house is usually made more minimal. Therefore, the porch also raise the ground level, arranging the steps outside.

In winter, especially in areas with sustainable snow cover, such the staircase on the porch requires constant cleaning from snow And still often turns into a rink. The porch with the staircase has large sizes. If the steps of the stairs are not protected from precipitation, they are moisturized and quickly destroyed by frost.

In areas with harsh snowy winter it is profitable to make the height of the porch to make the minimum, and place the stairs to place in the vestibule - In the Seine or veranda, as our ancestors did.

Sizes of the porch of a private house

The minimum sizes of the porch pad in front of the entrance door are shown in the picture.

Convenient height of steps for lifting on the porch, 12-18 cm. Width sticking 33-40 cm.

If the site is located at a height of 0.45 m. and more it is necessary to make a platform fence and stairs.The height of the fence and railing on the stairs not less than 0.9 m.

For the safe and convenient movement of people on the stairs arrange the handrails.Children of different ages on the stairs will be more security if the handrails are located in three levels at a height of 0.5 - 0.7 - 0.9 m.

The fence will not need If the steps do from one or two other sides of the porch.

The height of the porch in this embodiment should be no more than 1 meter. If such a porch is located at an altitude of more than 1 meter, then it is necessary to make a railing on each side of the descent from the stairs.

Standard Input Door Width 90 cm . Sometimes install the door width 120 cm. with two sash, and the flaps have different widths - 90 cm and 30. cm.

Entrance from the garage to the house. Minimum sizes of the "Porch" 60x60 cm.

In the house-held garage, the floor level is usually lower than on the first floor in the house.

Before the door from the garage to the house you have to arrange a "porch" with steps. So that the porch occupied less space, make it as shown in the figure.

Another option is the floor in the garage to do in the same level with the floor in the house. In this case, at the entrance to the garage is arranged ramp.

Street insulated entrance doors for home

Pay special attention to choosing an entrance door to heated room from the street. The door must have reliable seals and good thermal insulation. The door in the outer wall is installed so as to eliminate the cold bridge through the slopes bypassing the door box.

TERMO steel street door floor with thermal survey. Steel outer and inner parts of the web and boxes are separated by a layer of thermal insulation.

Do not put an ordinary single steel at the entrance from the street into heated the door - it will be freezing, covered by condensate and incident.

It is necessary to install a special steel street door, made using the thermal separation technology of boxes and canvas.

Entrance doors from a special door pVC profile and double-glazed windows will provide thermal protection and natural lighting of the hallway in the house.

You can also install doors from the composite metal-plastic profile of the window type, but made from the enhanced door profile.

Traditional entrance doors from the street from an oak massif

Or street doors of wood - better from an array of oak.

Two doors at the entrance to the house

Mounting diagram Double entrance door at the entrance to the house

In the harsh climate in outdoor wall at home install two entrance doors. The door of the door on the side of the street opens out, and the other is inside the room. The second inner door, along with the air interior between the doors, reduces heat loss and prevents frosting the outer door. In this embodiment outside, you can put an ordinary steel door. To the door, which is installed from the inside of the house, also does not prevent special requirements. You can install ordinary interroom door. It is not necessary to install locks on the inner door, it happens enough to equip the door by the retainer.

Installing two simple doors At the entrance in price may not be much more expensive than the installation of one special door with a thermal survey. Some owners for the summer period remove the interior door canvas, and with the onset of cold weather they return to place.

What to choose a tambour for a private house and do it at all? When answering this question, you should consider the way of life of the family, layout at home and climatic conditions terrain.

If the family leads the peasant lifestyle - holds a cattle, cultivates the household plot, then in the house it is profitable to make traditional senseswhich will unite all economic buildings in the same amount with the house. Conveniently from Seine to make another way out, in the direction of the household site. So often build in areas with harsh winter and high snow cover.

In the southern regions, economic buildings, summer cuisines Usually posted on panstone Distribution from the house. At the entrance to such a house are arranged a tambour-hallway, Which will protect interior With air conditioning from street heat and dust. The porch at the entrance to the house shads a large canopy.

In the house with urban lifestyle, family members most often move along the route House - Garage - Machine. There are only summer on the plot, and it goes through the summer doors in the living room. In this embodiment better having a vestse, urban version connecting the garage with residential premises. To store the outerwear is beneficial at the entrance to the house

If the garage stands apart from home or parking machines made under a canopy, then at the entrance to the house there are tambour-halls.

In the urban version often combine vestibule, senia and hallway.

Which Tambour is needed in a private house

The design of the ventilation of a residential, social or production building takes place in several stages. The air exchange is determined on the basis of the regulatory data used by the equipment and the customer's individual wishes. The volume of the project depends on the type of building: A single-storey residential building or apartment is calculated quickly, with a minimum amount of formulas, and serious work is required for the production facility. The method of calculating the ventilation is strictly regulated, and the initial data is written in SNiP, GOST and SP.

The selection of the optimal and cost of the air exchange system passes step by step. The design procedure is very important, since the efficiency of the final product depends on its observance:

• Determination of the type of ventsyystem. The designer analyzes the source data. If you want to ventilate a small residential premises, then the choice falls on sUPPLY SYSTEM With natural motivation. This will be enough when the air flow is small, there is no harmful impurities. If you need to calculate a large ventcomple for a plant or a public building, then the preference is given to mechanical ventilation with the heating / cooling function of the shapes, and if necessary, then with the calculation of the harm.
• Emission Analysis. This includes: thermal energy from lighting and machine tools; evaporation from machines; Emissions (gases, chemicals, heavy metals).
• Calculation of air exchange. The task of ventilating systems - removal from the premises of excess heat, moisture, impurities with an equilibrium or slightly different feed fresh air. For this, the multiplicity of the air exchange is determined, according to which the equipment is selected.
• Equipment selection. It is performed according to the obtained parameters: the required air temperature / exhaust air; temperature and humidity indoors; The presence of harmful emissions are selected by annotations or ready-made multicompleks. The most important of the parameters is the amount of air required to maintain project multiplicity. Filters, calorificates, recuperators, air conditioners and hydraulic pumps go as additional network devices providing air quality.

Calculation of emissions

The volume of air exchange and the intensity of the system is dependent on these two parameters:

• Norms, requirements and recommendations prescribed in SNiP 41-01-2003 "Heating, ventilation and air conditioning", as well as other, more highly specialized regulatory documentation.
• Actual emissions. Calculated by special formulas for each source, and are shown in the table:

Heat out, j.
Electric engine		N is the engine power at par, W; K1 - loading coefficient 0.7-0.9 k2η - work coefficient at one time 0.5-1.
Lighting devices
Human		n is the estimated number of people for this room; q is the amount of heat that allocates the body of one person. Depends on air temperature and intensity of work.
Surface of the pool		V - speed movement of air over the aqueous surface, m / s; T - water temperature, 0 s F - water mirror area, m2
Venting Education, kg / h
Water surface, such as swimming pool		P - mass production coefficient; F-square surface of evaporation, m 2; PH1, pH2 - partial pressure of saturated water vapor at a certain temperature of water and indoor air, Pa; RB is a barometric pressure. PA.
Wet floor		F is the area of \u200b\u200bthe wet surface of the floor, m 2; t C, T M - air temperature temperature measured by dry / wet thermometer, 0 C.

Using the data obtained as a result of the calculation of harmful selection, the designer continues to calculate the parameters of the ventilation system.

Calculation of air exchange

Specialists use two main schemes:

• According to integrated indicators. This technique does not provide for harmful emissions, such as heat and water. Conditionally call it "Method No. 1".
• The method taking into account excess heat and moisture. The conditional name "Method number 2".

Method number 1.

Unit of measurement - m 3 / h (cubic meters per hour). Two simplified formulas are used:

L \u003d k × v (m 3 / h); L \u003d z × n (m 3 / h), where

K is the multiplicity of air exchange. The ratio of the volume of the shapes for one hour, to the total air in the room, and the per hour;
V - the volume of the room, m 3;
Z - the value of the specific air exchange per unit of versa,
n - Number of units of measurement.

The selection of vinters is carried out on a special table. When the selection also takes into account the average speed of air flow through the channel.

Method number 2.

When calculating, heat and moisture assimilation is taken into account. If in a manufacturing or public building excess heat, then the formula is used:

where σq is the amount of heat dissipation from all sources, W;
C - thermal capacity of air, 1 kJ / (kg * k);
TYX - air temperature aimed at exhaust, ° C;
TNP - air temperature aimed at the impression, ° C;
Air temperature aimed at drawing:

where TP.3 is a regulatory temperature in work zone0 s;
ψ- coefficient an increase in temperature depending on the height of the measurement equal to 0.5-1.5 0 s / m;
H - the length of the shoulder from the floor until the middle of the hood, m.

When the technological process involves the allocation of a large volume of moisture, then another formula is used:

where G is the volume of moisture, kg / h;
DYX and DNP - water content for one kilogram of dry air shapes and hoods.

There are several cases described in more detail in the regulatory documentation when the required air exchange is determined by multiplicity:

k - the multiplicity of air change in the room, once a hour;
V is the volume of the room, m 3.

Calculation of section

The cross-sectional area of \u200b\u200bthe duct is measured in m 2. It can be calculated by the formula:

where V is the speed of the air masses inside the channel, m / s.

It differs for the main air ducts 6-12 m / s and lateral appendages not more than 8 m / s. The quadrature affects the bandwidth of the channel, the load on it, as well as the noise level and the module.

Calculation of pressure loss

The walls of the air duct are not smooth, and the inner cavity is not filled with vacuum, therefore, part of the energy of the air mass during the movement is lost on overcoming these resistance. The magnitude of the loss is calculated by the formula:

where ג - friction resistance, is defined as:

The formulas above are correct for circular channels. If the air duct is square or rectangular, then there is a formula for bringing the equivalent of diameter:

where a, b is the size of the parties of the canal, m.

Power of pressure and engine

Air pressure from blades H should fully compensate for the pressure loss P, while creating a calculated dynamic P d at the output.

Power electric engine Fan:

Selection of Calrifer

Often heating is integrated into the ventilation system. For this, the canorifers are used, as well as the recycling method. The device selection is carried out in two parameters:

• Q B is the limiting consumption of thermal energy, W / h;
• F K - Determination of the heating surface for the carrier.

Calculation of gravitational pressure

Applies only for the natural ventilation system. With it, its productivity is determined without mechanical motivation.

Equipment selection

According to the data on air exchange, form and size, the cross-section of air ducts and decisions, the amount of energy for heating is selected the main equipment, as well as fittings, deflector, adapters and other related parts. Fans are selected with a power reserve under peak periods of work, air ducts taking into account the aggressiveness of the medium and the volume of ventilation, and the calorificates and recuperators - based on the thermal requests of the system.

Design errors

At the project creation phase, errors and flaws are often found. It may be inverse or insufficient traction, strangling (the top floors of multi-storey residential buildings) and other problems. Some of them can be solved after the installation is completed using additional installations.

A vivid example of a low-qualified calculation is an insufficient thrust on the exhaust of production premises without particularly harmful emissions. Suppose Ventkanal ends with a round mine, towering over the roof by 2,000 - 2,500 mm. It is not always possible to raise it above and advisable, and in such cases the principle of torch emission is used. In the top of the circular ventshacht, a tip with a smaller diameter of the work opening is installed. A artificial narrowing of the section is created, which affects the rate of gas emissions into the atmosphere - it increases many times.

The method of calculating ventilation allows you to obtain a high-quality internal environment, correctly assessing negative factors, its worsening. Professional designers of engineering systems of any complexity are working at Mega.ru company. We provide services in Moscow and neighboring regions. The company is also successfully engaged in remote cooperation. All communication methods are listed on the page, please contact.

Natural room ventilation - is a spontaneous movement of air masses due to the difference in its temperature modes in not at home and inside. This type of ventilation is divided into a non-channel and channel, relatively able to work is continuous and periodic.

The systematic movement of fraumug, forces, doors and windows implies under the most the procedure of ventilation. The ventilation of the vagueless species is formed on a stable base in industrial-type rooms with tangible thermal discharge, organizing the desired frequency of air mass exchange in the middle of them, this process is called aerial.

In private and high-rise buildings more applied natural ventilation system channel view, channels in which are located in vertical position In specialized blocks, mines are either located in the walls themselves.

Calculating aeration

Aeration of industrial rooms summer guarantees air flow Through the lumens below Gate I. entrance doors. In the cool months, admission in the desired size is performed under the means of the upper lumen, from 4 m and more above the floor level. Ventilation over the whole year was performed using mines, deflectors and forces.

In winter, framouts are open only in areas above the generators. reinforced thermal discharge. During generation in the rooms of the building of unnecessary obvious heat, then temperature mode The air in it is constantly more than the temperature outside the building, and, in accordance, density is less.

This phenomenon leads to the presence of an atmosphere pressure difference out and inside the rooms. In the plane at a specific height of the room, which is referred to as the plane of the same pressures, this difference is absent, that is, equal to zero.

Above this plane there is some kind of excessive voltage, which leads to removal of the hot atmosphere outward At the bottom of this plane, the vacuum due to the influx of fresh air. Pressure forgoing air masses in the process of natural ventilation, can be established based on their calculations:

Natural ventilation formula

RE \u003d (VN - H) HG

• where H is the air density outside the room, kg / m3;
• vN - air mass density indoors, kg / m3;
• h - the distance between the supply opening and the center of exhaust, m;
• g is an acceleration of free fall, 9.81 m / s2.

The method of ventilation (aeration) of buildings with the help of drop-down fraamug is considered fairly true and effective.

When calculating the natural ventilation of the premises, the establishment of a section of the lower and upper lumens is taken into account. At first get the value of the section of the lower lumen. The model aeration is set.

Calculation of natural exhaust ventilation

Then, in connection from the section of the opening of the upper and lower, respectively, the supply and exhaust fraamug indoors in the room in the center of the structure of the structure, the degree of identical pressures is obtained, in this place the influence is also zero. In accordance, influence in the degree of focusing of the lower lumens will be equal to:

• where the average temperature of the air mass density indoors, kg / m3;
• h1- The high plane of the plane of the same pressures to the lower lumen, m.

At the level of the centers of the upper lumens, the excess voltage is formed above the plane of the same pressures, PA, equal to:

This is the pressure and has an impact on air extract. The overall voltage relating to the exchange of air flows in the room:

Natural ventilation speed

Air speed in the center of the lower lumen, m / s:

• where L is the necessary exchange of air masses, m3 / hour;
• 1 is a consumption coefficient depending on the design of the lower lumen flaps and the angle of their discovery (at 90 discovery, \u003d 0.6; 30 - \u003d 0.32);
• F1- Lower lumen area, m2

Then the losses, pa, in the lower lumens:

Having adopted that re \u003d p1 + p2 \u003d h (n - cf), and the temperature of the air of the air is TD \u003d TRZ + (10 - 15 ° C), determine the density of H and CP, which correspond to the temperatures of TN and TSR.

Excessive pressure in the plane of the upper lumen:

The necessary area of \u200b\u200bthem (m2):

F2 \u003d L / (2V22) \u003d L / (2 (2P2G / CP) 1/2)

Calculation and calculation of ventilation channels

The calculation of the natural system of conducting a channel view is closer to the establishment of the active incision of the air ducts, which for the purpose of access of the required number of air express the opposition properly the calculated voltage.

For the longest network path, the voltage costs in the duct channels are established as the sum of the voltage costs in absolutely all of its places. In each of them, pressure costs are formed with friction losses (RI) and costs in counteraction places (z):

• where R is the specific loss of stress in the length of the friction section, the P / m;
• l - Length of the site, m.

Live cross section area, m2:

• where L is air flow, m3 / h;
• v is the speed of air movement in the air duct, m / s (equal to 0.5 ... 1.0 m / s).

By setting the speed of air in the ventilation, and read the area of \u200b\u200bits active section and scale. With the help of specialized nomograms or table calculations for the rounded form of air ducts, the costs of friction voltage are set.

Natural ventilation calculation of air ducts

For the rectangular form of air ducts of this concept of ventilation, the diameter of DE is equilibrium to a rounded air duct:

dE \u003d 2 A b / (a \u200b\u200b+ b)

• where, a and b - the length of the parties of the rectangular duct, m.

In the case of using air ducts made from metal, their specific costs of friction pressure R, taken from nomograms for steel ducts, change, multiplying to the corresponding coefficient K:

• for slag-hydrogen - 1,1;
• for slag concrete - 1.15;
• for bricks - 1.3.

Excess pressure, PA, to overcome certain resistance for different sections is calculated for the equation:

• where - the sum of the coefficients of opposition on the site;
• v2 / 2 - Dynamic stress, Pa, taken from standards.

To create a concept of relaxed ventilation, it is preferable to beware of winding crops, a pluralistic number of valves and valves, since loss to local counteraction, as a rule, in the channels of air ducts are reached up to 91% of all costs.

Natural ventilation contains a small radius of exposure and the average performance for the rooms of the heat surplus in which the Council is small, which is possible to attribute disadvantages, and the ease of the system, low price and simplicity in service.

Natural ventilation example calculation

Total area - 60 m2;
bathroom, kitchen with gas stove, restroom;
Storage room - 4.5 m2;
The height of the ceilings is 3 m.

Concrete blocks will be applied for air duct equipment.

Air flow from the street according to standards: 60 * 3 * 1 \u003d 180 m3 / hour.

Air hood out of the room:
Kitchens - 90 m3 / hour;
bathroom - 25 m3 / hour;
toilet - 25 m3 / hour;
90 + 25 + 25 \u003d 140 m3 / hour

The frequency of updating the air masses in the pantry - 0.2 in 1 / hour.
4.5 * 3 * 0.2 \u003d 2.7 m3 / hour

The desired air output: 140 + 2.7 \u003d 142.7 m3 / hour.

Although there are multiple programs for ventilation calculations, many parameters are still determined by the old manner using formulas. Calculation of the load on ventilation, area, power and parameters of individual elements is made after the circuit and distribution of equipment.

This is a difficult task that is under the power of only professionals. But if you need to calculate the area of \u200b\u200bsome elements of ventilation or the cross-section of the air ducts for a small cottage, to actually cope with yourself.

Calculation of air exchange

If there are no poisonous secretions in the room or their volume is in permissible limits, the air exchange or ventilation load is calculated by the formula:

R.= n. * R.1,

here R1 - the need for air of one employee, in cubic meters / hour, n. - The number of permanent staff indoors.

If the room at one employee is more than 40 cubic meters and works natural ventilation, I do not need to count the air exchange.

For residential, sanitary and utility premises, the calculation of ventilation for maliciousness is made on the basis of the approved ambulance exchange rate:

• for administrative buildings (exhaust) - 1.5;
• halls (feed) - 2;
• conference rooms up to 100 people with a capacity (for feeding and extracting) - 3;
• rest rooms: influx 5, extract 4.

For industrial premises, in which hazardous substances are constantly or periodically, hazardous substances are distinguished into the air, the calculation of ventilation is carried out by harm.

Air exchange for harm (pairs and gases) are determined by the formula:

Q.= K.\(k.2- k.1),

here TO - the amount of steam or gas appearing in the building, in mg \\ h, k2. - The content of steam or gas in the outflow, usually the value is equal to the PDC, k1. - Gas content or steam in the impression.

It is allowed to concentrate the harm in the impression of up to 1 \\ 3 from the MPC.

For premises with excretion of excess heat, air exchange is calculated by the formula:

Q.= G.\\c.(tYX. – tN.),

here Gizb. - excess heat, extruded out, is measured in W, from - specific heat capacity by weight, C \u003d 1 kJ, tYX. - temperature removed from air room, tN. - Shape temperatures.

Calculation of thermal load

The calculation of the thermal load on ventilation is carried out by the formula:

Q.in \u003d.V.h *k. * p. * C.r(t.vN -t.nRO)

in the formula for calculating the thermal load on ventilation VN - External structure in cubic meters, k. - the multiplicity of air exchange, tWN - The temperature in the building is average, in degrees Celsius, tNRO - the air temperature is outside used in the calculations of heating, in degrees Celsius, r - air density, kg \\ cubic meter, Cf. - Air heat capacity, in KJ \\ cubic meter Celsius.

If the air temperature is below tNRO The multiplication of air exchange is reduced, and the heat flow rate is considered to be equal QB, permanent value.

If, when calculating the thermal load on ventilation, it is impossible to reduce the multiplicity of air exchange, heat consumption is calculated by heating temperature.

Ventilation heat consumption

Specific annual ventilation heat consumption is calculated as follows:

Q \u003d * b * (1-e),

in the formula for calculating the heat consumption for ventilation QO. - Common heat loss of the structure for the heating season, QB. - Domestic heat receipts, QS. - heat receipts outside (sun), n. - the coefficient of thermal inertia of walls and overlaps, E. - Lowering coefficient. For individual heating systems 0,15 , for central 0,1 , b. - coefficient heat loss:

• 1,11 - for tower buildings;
• 1,13 - for the buildings of multisective and multiplet;
• 1,07 - For buildings with warm attics and basements.

Calculation of diameter of air ducts

Diameters and cross-section of ventilation air ducts are calculated after the general system scheme is composed. When calculating the diameters of ventilation air ducts, the following indicators take into account:

• Air volume (supply or exhaust), which should go through the pipe for a given period of time, cubic meters;
• Air speed. If, in the calculations of the ventilation pipes, the flow rate of the flow is underestimated, the air ducts will be installed too much, which entails additional costs. The overestimated rate leads to the appearance of vibrations, strengthen the aerodynamic roe and increase the capacity of the equipment. The speed of movement on the influx of 1.5 - 8 m / s, it changes depending on the site;
• Ventilation pipe material. When calculating the diameter, this indicator affects the resistance of the walls. For example, black steel with rough walls has the highest resistance. Therefore, the calculated diameter of the ventilation duct will have to be slightly increased compared with the norms for plastic or stainless steel.

Table 1. Optimal air flow rate in ventilation pipes.

When known bandwidth Future air ducts, you can calculate the section of the ventilation duct:

S.= R.\3600 v.,

here v. - air flow speed, in m / s, R. - Air flow, cubic meters \\ h.

The number 3600 is a temporal coefficient.

here: D. - Diameter of the vent pipe, m.

Calculation of the area of \u200b\u200bventilation elements

The calculation of the ventilation area is necessary in the case when the elements are made of sheet metal and need to determine the amount and cost of the material.

The ventilation area is calculated by electronic calculators or special programs, they can be found in the internet.

We present a few table values \u200b\u200bof the most popular ventilation elements.

Diameter, mm.	Length, M.
	1	1,5	2	2,5
100	0,3	0,5	0,6	0,8
125	0,4	0,6	0,8	1
160	0,5	0,8	1	1,3
200	0,6	0,9	1,3	1,6
250	0,8	1,2	1,6	2
280	0,9	1,3	1,8	2,2
315	1	1,5	2	2,5

table 2. The area of \u200b\u200bdirect ducts of the circular cross section.

The value of the area in the square meter. At the intersection of the horizontal and vertical line.

Diameter, mm.		Corner, hail
	15	30	45	60	90
100	0,04	0,05	0,06	0,06	0,08
125	0,05	0,06	0,08	0,09	0,12
160	0,07	0,09	0,11	0,13	0,18
200	0,1	0,13	0,16	0,19	0,26
250	0,13	0,18	0,23	0,28	0,39
280	0,15	0,22	0,28	0,35	0,47
315	0,18	0,26	0,34	0,42	0,59

Table 3.. Calculation of the area of \u200b\u200btaps and semi-lines of the round.

Calculation of diffusers and lattices

Diffusers are used to feed or remove air from the room. From the correctness of calculating the number and location of ventilation diffusers, cleanliness and air temperature in each corner of the room depends. If you set diffusers more, the pressure in the system will increase, and the speed drops.

The number of ventilation diffusers is calculated as follows:

N.= R.\(2820 * v. * D * D),

here R. - bandwidth, in cubic meters / hour, v. - air speed, m / s, D. - Diameter of one diffuser in meters.

The number of ventilation grids can be calculated by the formula:

N.= R.\(3600 * v. * S.),

here R. - air flow in cubic meters / hour, v. - air speed in the system, m / s, S. - Summing area of \u200b\u200bone lattice, sq.m.

Calculation of the channel heater

The calculation of the electric type ventilation can be produced like this:

P.= v. * 0,36 * ∆ T.

here v. - the volume of air-passed through the calorifer in the cubic meters. \\ Hour, Δt. - The difference between the air temperature is outside and inside, which is necessary to provide the caloric.

This indicator varies within 10 - 20, the exact number is set by the client.

The calculation of the heater for ventilation begins with the calculation of the front cross section:

AF \u003d.R. * p.\3600 * VP.,

here R. - the volume of consumption of adhesives, cubic m. \\ H, p. - density of atmospheric air, kg \\ cubic meters, VP. - Mass air velocity on the site.

The size of the section is necessary to determine the size of the ventilation heater. If the cross-sectional area calculates it is too large, it is necessary to consider the option from the heat alleged cascade with the total calculated area.

The mass rate is determined through the front area of \u200b\u200bheat exchangers:

VP.= R. * p.\3600 * A.f. Fact.

For further calculation of the ventilation carrier, we determine the amount of heat for warming the air flow:

Q.=0,278 * W. * c. (T.p-T.y)

here W. - consumption of warm air, kg \\ hour, TP - Temperature of the supply air, degrees Celsius, T. - outdoor air temperature, degrees Celsius, c. - Specific air temperature, permanent value 1.005.

Since in the supply systems fans are placed in front of the heat exchanger, the heating air consumption is calculated as follows:

W.= R * P.

Calculating the ventilation calorifer, the heating surface should be determined:

APN \u003d 1,2Q.\ k.(T.s.T-T.s.V),

here k. - the return ratio of heat calorifer, Ts.t. - average temperature of the coolant, in degrees Celsius, TS.V. - the average temperature of the adhesive 1,2 - coefficient of cooling.

Calculation of displacing ventilation

When feeding ventilation indoors, the calculated ascending air flows in the places of high heat release are equipped. The bottom is served cool fresh airwhich gradually rises and at the top of the room is removed from the outstanding of heat or moisture.

With a competent calculation, the outstanding ventilation is much more efficiently mixed in the premises of the following types:

• halls for visitors in catering establishments;
• conference rooms;
• any halls with high ceilings;
• student audiences.

The calculated ventilation displaces less effectively if:

• ceilings below 2 m 30 cm;
• the main problem of the room is increased heat release;
• it is necessary to lower the temperature in indoor rooms with low ceilings;
• in the hall powerful air jurles;
• the temperature of the harm below, indoor air temperature.

Obsting ventilation is calculated based on the fact that the thermal load on the room is 65 - 70 W \\ sq.m, at a cost of up to 50 liters per cubic meter of air per hour. When heat loads Above, and the consumption is lower, it is necessary to organize a mixing system combined with cooling from above.