A ventilation device is necessary to organize constant air renewal. This is especially important if there are gas-flame appliances in the house - heating boilers, hot water columns and kitchen stoves. Getting Started with Equipment ventilation devices, you need to carefully study the rules for their arrangement and strictly follow them during design and installation.
The role of ventilation in a room with a gas boiler
The process of burning fuel in gas boiler occurs with the active participation of atmospheric oxygen. Therefore, its content in the boiler room quickly decreases, gas combustion becomes incomplete, which is why soot more actively settles on the walls of the chimney, and the room becomes stuffy. A person’s well-being in such conditions can deteriorate sharply, even to the point of loss of consciousness.
The situation can become more complicated if gas leaks form from the internal gas pipeline in the house. The situation becomes explosive with possible dire consequences.
To prevent this from happening, a ventilation system must be installed in each room with gas appliances. It allows you to continuously refresh the room by supplying fresh air from the external space and removal of contaminated.
Fresh air enters the boiler room through ventilation holes within the walls
Requirements for ventilation in a private house with a gas boiler
Most often used for private homes gas boilers low power - up to 30 kilowatts. Their installation does not require separate boiler rooms. Such equipment can even be placed in kitchens that meet the following requirements:
In addition to the ventilation device, there are some special requirements for the boiler installation site. Boiler rooms are allowed to be installed:
- in attached to residential building premises;
- in separate buildings;
- in attics;
- in separate rooms in the house.
Boiler rooms are often equipped in ground floors or basements building. This does not apply to devices running on liquefied gas. Its density is higher than that of air and, if a leak occurs, it can accumulate near the floor, being initially invisible at human height. This creates an explosive situation.
Standardization of ventilation during operation of gas boilers
It should be noted that gas equipment is a source of increased danger. Therefore, the procedure for designing and operating boiler houses is standardized by the state, and compliance with these requirements is strictly controlled by it.
To streamline all requirements, “Building Norms and Rules 2.04.05” have been developed and applied. II-35", and II-35–76. The basic requirements for premises for gas boilers are set out above.
This document also regulates:
- procedure for developing technical documentation;
- sizes and capacities of ventilation systems for different types buildings;
- their types and order of arrangement.
How to arrange ventilation of a gas boiler room in a private house
There are and are used several types of ventilation for rooms with gas boilers:
- supply;
- exhaust;
- supply and exhaust;
- natural.
None of the listed types is practically used in isolation. Most in effective ways ventilation are combinations of these methods in various combinations.
Natural supply ventilation
This is the most common and mandatory way of supplying fresh air to the boiler room.
In the scheme of supply natural ventilation, air enters through the inlets at the bottom of the room and is removed through the upper exhaust ducts due to natural circulation
The manufacture of the ventilation duct is carried out as follows:
When choosing a place to install the ventilation duct, you should take into account the fact that its outlet must be at least a meter away from the boiler, then the cold air from it will not affect the operation of the unit. Of course, modern automation can easily cope with this circumstance, but there is no need to overload it unnecessarily.
The influence of external conditions, including weather, on the operation of the ventilation duct should be taken into account, but one of its advantages is undeniable - it will work independently of the power grid, ensuring a constant supply of air from outside.
Video: how to make a ventilation duct for a boiler room
Forced exhaust ventilation
Combined supply and exhaust systems with wide adjustment capabilities consist of fans, filters and air heaters. Essentially this is climate systems. Considering that modern boilers equipped with various regulators that automatically control its operation depending on the microclimate in the boiler room, the use of such ventilation devices ensures optimal performance heating unit and contributes to significant fuel savings.
Supply ventilation systems supply and extract air due to the operation of fans installed in laid channels
Our next article presents detailed instructions for installation of supply- exhaust ventilation with calculations: .
Duct and free ventilation systems
One of the characteristics for classifying ventilation systems is their design features and the way air moves.
A duct ventilation system involves the creation or use of specially designed air ducts determined by the building design. In this case, various niches and installation space are used suspended ceiling, ventilation shafts. In places where the building structure does not provide for such elements, ventilation ducts are laid directly along the walls and masked with the finishing details of the room.
The duct ventilation system involves laying supply and exhaust air ducts
It should be noted that the ventilation of a building cannot be considered only for a separate room, even such a specific one as a boiler room. All air flows are combined into a single system and removed from the house by force or naturally. Gas equipment can be used indoors in the kitchen (stove), bathroom ( geyser), living room (gas fireplace). The principles of air exchange in all these objects are subject to the same requirements.
The main means of transporting air are pipes. The most popular:
- rectangular products made of galvanized steel. They are easy to install and are always provided with components - corners, bends, etc.;
- aluminum corrugated pipes. They practically do not require additional fittings, since they themselves are flexible products. Quite convenient to use;
- plastic air ducts of rectangular and round cross-section.
All mentioned products can be retrofitted with decorative air intake grilles, dampers, connecting elements. Thanks to their use, installation of the air duct has become simple and accessible. with my own hands even without the appropriate qualifications.
The small size and weight of the air duct elements and the presence of all the necessary fastening and connecting products allows you to build a ventilation duct of any configuration with your own hands
Installation procedure supply and exhaust ventilation in the boiler room with your own hands:
Video: which pipes to use for ventilation
Calculation of ventilation cross-section
To correctly calculate the pipeline cross-section ventilation system boiler room, you will need the following data:
- The cubic capacity of the boiler room, depending on the height of the room. According to SNiP requirements, its height should not be less than 6 meters. Obviously, in conditions village house such a requirement is impossible to fulfill. When calculating, it must be taken into account that when this indicator decreases by 1 meter, the amount of air required for fuel combustion must be increased by 25%;
- Air mass flow velocity (at least 1 m/s).
- Air exchange rate. The value depends on the height of the boiler room.
The result of the calculation will be the air requirement, on the basis of which, using special tables, the cross-section of the ventilation system pipeline can be determined.
The calculation is made using the relationship V = L x S X (6 - H) x 1.25 x n, where:
- V is the volume of air for fuel combustion;
- L -
room length;
- S -
room width;
- H -
room height;
- n -
frequency of air change in the boiler room equal to 3.
Thus, when determining the air requirement, the actual size of the room and the increase in air turnover are taken into account. Having received the desired value, the diameter of the air duct can be selected from the table.
Table: dependence of the duct diameter on the required air flow
| Diameter air duct, mm |
Air flow in m 3 /hour at speed in m/s | |||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
| 100 | 28,3 | 56,5 | 84,8 | 113 | 141 | 170 | 198 | 226 |
| 125 | 44,2 | 88,3 | 132 | 177 | 221 | 265 | 309 | 353 |
| 140 | 55,4 | 111 | 166 | 222 | 277 | 332 | 388 | 443 |
| 160 | 72,3 | 45 | 217 | 289 | 362 | 434 | 506 | 579 |
| 180 | 91,6 | 183 | 275 | 366 | 458 | 549 | 641 | 732 |
| 200 | 113 | 226 | 339 | 452 | 565 | 678 | 791 | 904 |
| 225 | 143 | 286 | 429 | 572 | 715 | 858 | 1001 | 1145 |
| 250 | 177 | 353 | 530 | 707 | 883 | 1060 | 1236 | 1413 |
To ventilate rooms with gas appliances, it is advisable to install a duplicate ventilation system so that one of them works under any circumstances.
When there is a power outage, ventilation of the premises will be carried out through natural circulation channels.
Video: calculation of air exchange in a boiler room
Ventilation system testing
Checking the functionality of the ventilation system is very simple. It is enough to take a strip of newsprint and bring it to the pipeline grate. If she pulls herself towards it, it means there is a pull. But in this way you can only establish its presence or absence.
The quantitative characteristics of thrust are measured using a wind force measuring device. Its impeller must be placed inside the ventilation duct and this indicator must be determined on a scale. Knowing the size of the pipeline cross-section, it is easy to calculate the performance of the system, that is, its sufficiency to ensure required quantity air in the room for normal combustion in the boiler.
Closed combustion boilers with coaxial chimneys. In them, air is supplied to the firebox directly from the atmosphere through pipes of a special design, and the room air does not take part in combustion.
The ventilation duct of the boiler room should not be connected to the air lines of the general exhaust. This will prevent the gas from spreading throughout all areas of the house.
You may also find this material about certification of ventilation systems useful:
The main reasons for the deterioration of draft in the ventilation system
Among these it should be noted:
- difficulties encountered with the flow of outside air into the boiler room after replacing traditional window units with double-glazed windows. Their tightness significantly reduces the possibility of air penetration;
- the same consequences after replacing doors if the gap between the floor and the bottom edge is minimal or absent;
- decrease in natural draft in the hot season due to a decrease in temperature difference outside and inside the house;
- the appearance of stagnant zones or zones with low pressure during strong winds in the atmosphere, which also negatively affects the operation of ventilation systems, so in such conditions additional draft control is needed.
During operation forced ventilation The boiler room needs to select fans with an impeller that does not spark from impacts. Products made from aluminum alloys, copper or plastic.
The inadequacy of the ventilation system of a gas boiler house is dangerous not only for health, but also for human life. In addition, it reduces the heating efficiency. Excessive ventilation leads to disruption of the thermal regime, worsening living conditions in the house. When starting to install ventilation yourself, try to get qualified advice from a specialist and take into account his comments. I wish you success!
When developing a project and building an individual home, it is necessary to construct many utility networks: electrical, water supply, sewerage and, of course, ventilation. The comfortable indoor microclimate largely depends on the latter. Therefore, the installation of ventilation ducts in a private house must be carried out in strict accordance with existing norms and rules, which will be discussed below.
The need to install ventilation
Owners of their own cottages recently faced the problem of installing an effective room ventilation system. Previously, a small ventilation duct in a private house coped well with the tasks assigned to it. After all, the walls are made of brick and wooden windows They perfectly allowed air to pass through, which was necessary for ventilation.
But in modern construction Mostly non-breathable materials are used:
- polymer windows that prevent the appearance of cracks and cracks;
- frame structures protected by polyethylene membranes;
- roofs equipped with steam and wind protection films.
All of the above building elements completely block natural air flow. Consequently - high humidity air, which leads to condensation on the glass, moisture on the walls and mold in the corners of the rooms.
Note!
Similar problems are faced by residents of old houses, who replaced their existing wooden windows with plastic ones with their own hands and did not take care of designing the supply ventilation ducts.
Ventilation network elements
Central exhaust duct
The instructions regulating the process of construction of individual dwellings state that duct ventilation for the house should be provided at the stage of drawing up project documentation. If for some reason this was not done, you can arrange an air intake and removal system in finished house. For this purpose, ready-made ventilation ducts are used.
Note!
The cost of installing ventilation in an already constructed building can be much higher than constructing this utility network directly during the construction of the house.
In the vast majority of cases, the mentioned method is used to equip an old, but thoroughly renovated house with supply and exhaust ducts.
By installing ventilation ducts, and possibly additional mechanical equipment(fans, heat exchangers, filters, etc.) you can avoid negative consequences described in the previous section.
Before starting the installation of central and peripheral air ducts, it is necessary to decide on the type of air exchange system:
- natural - in a modern private house it is not very effective, since it is sealed window systems prevent the flow of fresh air, and temperature changes during the cold season reduce the efficiency of traction;
- supply air - suitable for private houses with an area of up to 300 square meters;
- supply and exhaust - the most effective system, which allows, in the presence of a recuperator, not only to ventilate all rooms, but also to create a comfortable temperature in them.
All of them except small nuances, are designed according to the same principle, therefore below we will discuss in detail the features of installing ventilation ducts for the supply system.
Note!
In addition to ventilation of residential and auxiliary premises, ventilation of sewerage in a private house is also necessary.
For its manufacture, special types of air ducts are used.
Installation of mechanical ventilation
The system for the forced supply of fresh air and removal of contaminated air masses is designed according to the following principles:
- Two ventilation ducts are installed on the roof of a private house (usually in the kitchen area), which will serve as the basis for the entire future system. One of them serves to suck in air, the other to remove it from the premises.
- Installed on the exhaust air duct electric fan, equipped electronic system on and off. Operating modes are switched based on information received from external sensors, which control humidity and temperature in rooms.
- The entrances of ventilation ducts indoors must be installed so that the incoming air enters the living quarters (bedroom, living room), passes through the corridor, kitchen and sanitary block, where it enters specially equipped hoods.
As a result of this organization of air flows, moisture and unpleasant odors generated in the kitchen are prevented from entering other rooms of the house.
Air supply system
As mentioned above, laying ventilation ducts in an already built house is very problematic. In this case, you will either have to punch holes in the walls, and this is impossible in some cases, or install air ducts open method, which will have an extremely negative impact on the interior.
Nai the best option- construct a system of air channels in the attic, and arrange their outlets on the ceiling, masking unsightly openings with decorative grilles.
The material for arranging ventilation is ready-made plastic or metal-plastic ventilation ducts of a suitable cross-section.
They are:
- round;
- rectangular.
The latter type is preferable as it is easier to install on site.
In addition, you will need:
- grids;
- valve;
- connectors;
- gratings and so on.
To ensure that the installed ventilation ducts work with maximum efficiency, it is advisable to follow the following tips when installing them:
- It is better to make two supply channels in each living room, which will allow pumping a larger volume of air.
- The cross-section of the air ducts and the power of the fans must be calculated based on the area of the premises.
- Incoming air ducts should be present only in residential premises, while in auxiliary premises they should be installed exhaust system.
Outgoing air channels
The central channel, through which polluted air will be removed from the premises, is installed on the roof in the kitchen area. The point is that, unlike supply air ducts, the exhaust system should be as short as possible. This will avoid the formation of condensation and other problems leading to disruptions in the functioning of the ventilation network.
Note!
This arrangement of the air removal pipe is also due to the fact that a stove is installed in the kitchen, which, as a rule, is the source of the largest amount of harmful impurities.
You should also know that the air removed from the premises is warmer than the air masses located outside. Therefore, it is imperative to take care of the insulation of the outlet channels, otherwise moisture will condense inside.
In addition to the central pipe, peripheral pipes are installed. Their entrances are mounted above the kitchen, bathroom and toilet.
To increase the efficiency of exhaust ventilation, it is recommended to install a fan in the system. Hood over gas oven and the heating boiler pipe must enter the air channel after it (inserts are used for this).
Air ducts in the boiler room
One of the features of a private house is the presence of a boiler that heats the premises. Often it is installed in the kitchen, but sometimes a special room is allocated for it - a boiler room. It must also be equipped effective system removal of air contaminated with combustion products.
When manufacturing a boiler room ventilation system, the following rules should be followed:
- The room is equipped with two ventilation ducts leading outside. One of them will serve to remove combustion products, the second will purify indoor air.
- There is no need to install a fan in the duct intended for smoke removal. It will constantly fail.
- The gas mixture that is discharged through the ventilation duct is much hotter than the surrounding air. Therefore, moisture can constantly form on the pipe walls, which negatively affects the operation of the boiler. To avoid this, the pipe must be insulated with mineral mats.
- A ventilation duct designed to ventilate a room, on the contrary, should be equipped with a fan that can rotate in both directions. This will increase the volume of incoming and outgoing air.
Ventilation for fireplace and stove
If a fireplace or solid fuel stove is installed in any of the living rooms, you should take additional measures to ensure supply to this premises clean air and removal of combustion products.
This will allow you to create the most favorable conditions for complete combustion of wood or coal, because, as you know, flames cannot exist without oxygen.
In addition, if the ventilation system is ineffective and there is a lack of oxygen, carbon monoxide and other hazardous products are released during combustion, which, when accumulated in a room, can cause harm to health and even lead to death.
Many people do not install separate air ducts into the room, preferring to open the window. But in this case, you will be faced with inefficient use of heat, because most of it will evaporate during slot or burst ventilation.
Installation of air ducts on the roof
The most problems arise when arranging the outlets of ventilation ducts through the roof covering.
In order not to make unnecessary holes in the tiles or slates and to avoid rainwater getting into the attic, when installing air pipes, you must adhere to the following tips:
- Before constructing a ventilation network, it is advisable to draw up a plan indicating the locations of all air ducts, including their exit points through the roof.
- To arrange the ventilation ducts in question, it is necessary to use special parts. As a last resort - a stainless steel pipe with insulation.
- Before installation central channel It is advisable to make all the necessary holes in it in advance, which will simplify further work on assembling the entire ventilation system.
- Places where the pipe is adjacent to certain structural elements should be sealed. Any silicone compound or cement mortar will do.
Advice!
After processing the joints, it is necessary to suspend ventilation installation work until complete.
The central air channels must be strictly vertical, otherwise there is a danger of moisture forming on the inner surface pipes
Disadvantages of forced ventilation
Despite the obvious advantages, mechanical ventilation It also has some disadvantages that you should be aware of:
- filtering air quickly becomes clogged with dust, which requires constant maintenance.
- Electrical equipment (fans, heat exchangers) consumes electricity, increasing utility costs.
Advice!
If technical specifications allow, it is advisable to focus on the design of natural ventilation, the performance of which is sufficient in most cases.
Conclusion
The correct selection and installation of ventilation ducts in a private house is the key to effective and uninterrupted operation ventilation system. You can learn more about the arrangement of ventilation systems from the video in this article.
From correct device ventilation depends on the microclimate of the house, which has a direct impact on the well-being and comfort of all its residents. Properly constructed ventilation ducts in a private home will ensure stable air exchange. They will create conditions for regular supply of fresh portions and unhindered removal of polluted air.
We suggest that you familiarize yourself with the specifics of constructing duct ventilation in a low-rise country property. We describe in detail the technology of installing a ventilation system, placing equipment, laying and fastening ventilation ducts. Practice-tested improvement options are discussed.
The information presented for consideration is based on building regulations. Taking into account our recommendations, you can build effective ventilation yourself. For visual understanding, diagrams, photo guides and video instructions are attached to the text.
Ventilation of the room is necessary in order to create optimal conditions for the life of people and the existence of furniture and equipment located in the house.
If in apartment buildings everything has already been done by the specialists who erected the building, but during the construction of private real estate this issue is often overlooked.
Sometimes the installation of ventilation ducts is considered a waste of time and money. However, they are an obligatory part of the project implementation, ensuring favorable living conditions and long service life of building structures
This is a fundamentally erroneous opinion. Musty air, sweaty windows, unpleasant odors from the bathrooms, the aromas of fried food along with fumes will enter all rooms and even the bedroom. Without a properly designed and assembled ventilation system comfortable life the inhabitants of the house will be at risk.
Ventilation in a private house can be:
- natural;
- mechanical;
- mixed.
The first type is based on the natural process of circulation of air masses. No mechanisms are used to pump air into the house. It comes from the street, penetrating through micro-ventilated windows or supply valves arranged in the most suitable places.
In rooms of the house that do not have valves installed, air circulates through doorways and through cracks between the door and the floor.
Rules for installing ventilation pipes
A properly equipped ventilation system will perform its functions efficiently and will not create problems for the homeowner. To do this, it is important to lay ventilation ducts in the house, taking into account the rules and recommendations.
Firstly, the size of the exhaust ventilation duct in the room must have a diameter of at least 10x10 cm or 15x15 cm. It is better to use ready-made pipes than to make ducts from plasterboard - this will save installation time, and air flows better through the pipe.
For the arrangement of ventilation ducts, galvanized metal and plastic rigid or flexible pipes various diameters
Secondly, ventilation pipes must protrude above the roof to a certain height, depending on their location. Thus, the length of the vertical section of the ventilation duct should on average be from 1.5 to 3 meters. If in overall design the pipes do not fit into the house, then you can use ventilation outlets in the roof.
The height of the ventilation ducts above the roof level is assumed to be equal to the height of the chimneys. It depends on the location of the pipes relative to the ridge ridge. It is important to protect the outlet opening with a grate to prevent birds and insects from entering the shaft
Thirdly, according to the regulations, it is necessary to provide ventilation to the boiler room and the room located above the boiler room. Moreover, the purpose of this room does not matter. This could be an office, library, bedroom or living room.
Fourthly, it is important to distinguish between the concepts of chimney and ventilation. In the first case, combustion products enter the channel, and in the second, exhaust air from the room itself. Under no circumstances should these 2 channels be combined into one. This is a gross violation.
Ventilation outlets fit well into general idea roof design. You can choose the model that best suits the color
Fifthly, in the kitchen you need to provide 2 separate ventilation channels - and for supply air. The second option is to use a special grille where the air duct is connected and there is a separate hole for air to flow into the room. Or a window with micro-ventilation would be a good solution.
Thoughtful design solutions with a stepped ceiling can disguise any ventilation system
Sixth, if the house has rooms intended for household needs - a dressing room, laundry room, pantry, washing room and other purposes, then it is necessary to design a ventilation duct there. In such rooms there are no windows through which air could flow.
Seventhly, when a ventilation duct is laid in a wall, it is important that it is not load-bearing. Arrange them in external walls not recommended - due to temperature changes, condensation will always form there.
When installing a ventilation duct in the wall, rooms such as the kitchen, bathroom, toilet, boiler room should be nearby
Eighth rule - wooden structures The ceiling and roof should not adjoin or touch the stone or brick ventilation duct. For a tree, such a neighborhood can be disastrous.
The ninth rule is that it is undesirable to use only a window as a supply valve. She's not the best option. A sore nasopharynx in the morning, if there is a sudden change in weather overnight, will be a problem for the owner of the house who slept with the window open. This is especially true in autumn and spring period.
Tenth rule - when it is not possible to make ventilation ducts in the room, you can install supply valve, having drilled through hole in the wall. And at the top, right under the ceiling, drill a hole for installing an exhaust valve. This option for room ventilation can provide the room and its occupants with fresh air.
To calculate the cross-sectional area of exhaust pipes, we use the formula:
where: S—total area of exhaust ducts, m 2 ;
V – speed of air movement in the exhaust duct, m/s;
3600 – seconds in 1 hour.
The speed of air movement in the exhaust duct depends on its height and the temperature difference between the indoor and outdoor air.
The temperature in the pigsty during the transition period is 18ºС, in the winter - 18ºС. The height of the exhaust ducts is 6 m.
Temperature difference ( 
t) during the transition period is:
Temperature difference ( 
t) in winter period is:
Then the speed of air movement in the exhaust pipe during the transition period will be equal to 1.76 m/s, and in the winter – 2.12 m/s.
Calculation of exhaust pipes for hourly ventilation volume
during the transition period
in winter
With a cross-section of 1 exhaust pipe of 0.64 m2 (0.8×0.8), we find that at a height of 6 m the number of working pipes should be as follows:
during the transition period
(pipe)
in winter
(pipes)
Calculation of exhaust pipes for hourly ventilation volume
determined by dioxidecarbon
The total area of exhaust ducts with a height of 6 m will be:
during the transition period
in winter
With a cross section of 1 exhaust pipe of 0.64 m 2 (0.8 × 0.8), we find that at a height of 6 m the number of working pipes should be as follows:
during the transition period
(pipe)
in winter
(pipe)
Calculation of supply channels for hourly ventilation volume
determined by water vapor
We determine the total cross-sectional area of the supply channels, based on the fact that it is 80% of the cross-sectional area of the exhaust pipes. For the transition period:
(PC.)
For the winter period:
The number of supply channels will be:
(PC.)
Calculation of supply channels for hourly volume
determined by carbon dioxide
We determine the total cross-sectional area of the supply channels, based on the fact that it is 80% of the cross-sectional area of the exhaust pipes. For the transition period:
(PC.)
For the winter period:
Then the number of supply channels will be:
(PC.)
Calculation of air exchange rate
The air exchange rate in the pigsty is determined by formula 6:
(6)
where: K p - air exchange rate, times;
L – hourly ventilation volume, m 3 / h;
V p – volume of the room, m 3.
The volume of the room (cubic capacity) is 5832 ( 
) m 3 .
The air exchange rate when calculated using water vapor is:
during the transition period
in winter
The air exchange rate when calculating carbon dioxide is:
Calculation of room area and cubic capacity per head
The area of the pigsty is 
, thus, the area of the room for 1 head will be equal to
The cubic capacity of the room is 5832 m 2, and for 1 head
Analysis of calculated data
The calculations showed that air exchange, calculated using water vapor, during the transition period is 21578 m 3 /h, in winter - 18480 m 3 /h. And the air exchange calculated using carbon dioxide is 29,300 m 3 /h. Analysis of these data shows that air exchange calculated using carbon dioxide will ensure the removal of water vapor and the relative humidity will not exceed zoohygienic standards.
You can check using the following formula:
Let us use this formula to determine the moisture content in the pigsty under the condition of air exchange calculated using CO 2 . We take into account that in this formula all quantities are known, except 
.
,
The absolute humidity in the pigsty, subject to air exchange in it, calculated by carbon dioxide, will be equal to 7.89 g/m 3 . Since at an air temperature in a pigsty of 18°C, the humidity at maximum saturation will be equal to 15.36 mm Hg, the relative humidity will be:
Consequently, air exchange calculated using carbon dioxide will ensure the removal of water vapor from the pigsty, so we take the data obtained from CO 2 as the basis for calculations.
Air exchange per 1 quintal of live weight is 19.6 m 3 /h in the transition period, 16.8 m 3 /h in winter, and 26.7 m 3 /h for carbon dioxide. From this it can be seen that not a single indicator corresponds to the microclimate parameters, since the air exchange per 1 quintal of mass should be 45 m 3 / h in the transition period, and 35 m 3 / h in the winter.
The air exchange rate in the pigsty is 5 times per hour. Such a frequency of air exchange can only be ensured by forced ventilation with an artificial draft stimulator.
Calculation of the room area per 1 head showed that 1 fattening pig accounts for 1.62 m2, excluding aisles. According to zoohygienic requirements, 1 head should have 0.8 m2, therefore, this figure meets the requirements.
is a system in which there is no forced driving force: a fan or other unit, and the flow of air occurs under the influence of pressure changes. The main components of the system are vertical channels starting in the ventilated room and ending at least 1 m above the roof level. The calculation of their number, as well as the determination of their location, is carried out at the design stage of the structure.
The temperature difference at the lower and upper points of the duct causes the air (it is warmer in the house than outside) to rise upward. The main indicators that affect the traction force are: the height and cross-section of the channel. In addition to them, the efficiency of the natural ventilation system is affected by the thermal insulation of the shaft, turns, obstacles, narrowing in the passages, as well as wind, and it can either contribute to the draft or reduce it.
Such a system has a fairly simple arrangement and does not require significant costs both during installation and during operation. It does not include mechanisms with electric drives, it operates silently. But natural ventilation also has disadvantages:
- operational efficiency directly depends on atmospheric phenomena, so it is not used optimally for most of the year;
- performance cannot be adjusted, the only thing that needs to be adjusted is air exchange, and then only downward;
- in the cold season it causes significant heat loss;
- does not work in hot weather (there is no temperature difference) and air exchange is possible only through open vents;
- If work is ineffective, dampness and drafts may occur in the room.
Performance standards and natural ventilation channels
The optimal location for the channels is a niche in the wall of the building. When laying it should be remembered that the best traction will be when it is level and smooth surface air ducts To service the system, that is, cleaning, you need to design a built-in hatch with a door. To prevent debris and various sediments from ending up inside the mines, a deflector is installed above them.
According to building regulations the minimum performance of the system should be based on the following calculation: in those rooms where people are constantly present, the air should be completely renewed every hour. As for other premises, the following should be removed:
- from the kitchen - at least 60 m³/hour when using an electric stove and at least 90 m³/hour when using a gas stove;
- baths, toilets - at least 25 m³/hour, if the bathroom is combined, then at least 50 m³/hour.
When designing a ventilation system for cottages, the most optimal model is one that involves laying a common exhaust pipe through all rooms. But if this is not possible, then the ventilation ducts are laid from:
Table 1. Ventilation air exchange rate.
- bathroom;
- kitchens;
- storage room - provided that its door opens in living room. If it leads to the hall or kitchen, then only a supply duct can be installed;
- boiler room;
- from rooms that are separated from rooms with ventilation by more than two doors;
- if the house has several floors, then starting from the second, if there is entrance doors From the stairs, channels are also laid from the corridor, and if there are none, from each room.
When calculating the number of channels, it is necessary to take into account how the floor on the first floor is equipped. If it is wooden and mounted on joists, then a separate passage is provided for air ventilation in the voids under such a floor.
In addition to determining the number of air ducts, the calculation of the ventilation system includes determining the optimal cross-section of the ducts.
Return to contents
Channel parameters and ventilation calculations
When laying air ducts, both rectangular blocks and pipes can be used. In the first case minimum size side is 10 cm. In the second smallest area air duct cross-section is 0.016 m², which corresponds to a pipe diameter of 150 mm. A volume of air equal to 30 m³/hour can pass through a channel with such parameters, provided that the height of the pipe is more than 3 m (with a lower value natural ventilation not provided).
Table 2. Ventilation channel performance.
If it is necessary to increase the performance of the air duct, then either the cross-sectional area of the pipe expands or the length of the channel increases. The length, as a rule, is determined by local conditions - the number and height of floors, the presence of an attic. In order for the traction force in each of the air ducts to be equal, the length of the channels on the floor must be the same.
To determine what size ventilation ducts need to be laid, it is necessary to calculate the amount of air that needs to be removed. It is assumed that outside air enters the premises, then it is distributed into rooms with exhaust shafts and is exhausted through them.
The calculation is made floor by floor:
- The smallest amount of air that should come from outside is determined - Q p, m³/hour, the value is found according to the table from SP 54.13330.2011 “Residential multi-apartment buildings” (Table 1);
- According to the standards, the smallest amount of air that needs to be removed from the house is determined - Q in, m³/hour. The parameters are specified in the section “Performance standards and natural ventilation channels”;
- The obtained indicators are compared. The minimum productivity - Q р, m³/hour - is taken to be the largest of them;
- For each floor, the height of the channel is determined. This parameter is set based on the dimensions of the entire building;
- According to the table (Table 2), the number of standard channels is found, and their total performance should not be less than the minimum calculated;
- The resulting number of channels is distributed between rooms where air ducts must be present.
