Ventilation of residential buildings is one of the key points in providing a comfortable air environment for people. Poor air circulation in a home can not only negatively affect the health of residents, but also require spending on additional exhaust systems. Existing air ducts are also one of the main points of ensuring fire safety. In this material we will explain how ventilation works in apartment building and what activities can increase the effectiveness of its work.
Purpose of general house ventilation
The air in a residential apartment is always susceptible to pollution. Smoke from cooking, fumes from the bathroom, unpleasant odors and dust - all this ends up in the air and creates unfavorable living conditions for people. Stagnant air can even lead to the development of diseases such as asthma and allergies. That is why every apartment building must be equipped common system ventilation.
Functions of ventilation in a residential area:
- ensure the penetration of clean air into apartments;
- remove dust and other impurities harmful to health along with the exhaust air;
- regulate humidity in residential and utility rooms.
The majority of the urban population of our country lives in panel houses built during Soviet times, while others are moving to new buildings. Providing ventilation for residential buildings is mandatory requirement during the construction of houses. However, the level of ventilation in multi-apartment residential buildings remains quite low. It is customary to save on air duct systems during construction.
On at the moment you can meet the following types ventilation in residential buildings:
- with natural inflow and exhaust;
- with forced air movement through ventilation units.
IN modern houses Elite class heating and ventilation systems comply with the latest standards and are created using special equipment and materials. For ventilation of multi-storey panel-type residential buildings, natural air exchange is used. The same applies to Soviet-era brick residential buildings, as well as modern budget-class buildings. Air must flow through the openings between the doors and the floor, as well as special valves on plastic windows.
Ventilation in panel house works as follows. Air is discharged upward through vertical ventilation shafts, thanks to natural draft. It is pulled outside the house through a pipe located in the roof or attic. When air enters an apartment through open windows or doors, it rushes to those located in the kitchen and bathroom - where purification from smoke and moisture is most needed. Thus, stagnant air is discharged into the pipe, and clean air enters the room through the windows.
If you stop the flow fresh air, ventilation will not work effectively. Residents of apartments in apartment buildings often forget about natural ventilation of the room when installing additional exhaust systems. Here is a list of typical mistakes during repairs that stop air circulation:
- installation of blind double-glazed windows made of metal-plastic;
- eliminating the gap between door leaf and floors when replacing interior doors;
- installation axial fans in the toilet (affects the ventilation of neighboring apartments).
When decorating living rooms, it is worth remembering to create natural paths for ventilation. Can be installed plastic windows with special valves that will automatically supply air from the street.
Interior doors should be selected in size so that they do not stand close to the floor. When installing additional fans, you can configure them for supply.
Ventilation schemes for residential buildings
Depending on the construction plans, ventilation may have a completely different design. In this section we will try to figure out how ventilation works in a panel house using diagrams and talk about the degree of effectiveness of one or another type of ventilation.
The most successful ventilation scheme in a panel house is individual, when each apartment has a separate duct with access to the roof.
In this case, the ventilation shafts are not connected to each other, the air quality improves, and polluted air from neighboring apartments does not enter the house. Another variation of this ventilation scheme in a Khrushchev building is that from each apartment separate channels lead to the roof, where they are connected into a single pipe that carries air masses to the street. 
Unfortunately, quite often the simplest, but ineffective method of ventilation is used, in which air from all apartments enters a single large shaft - the same way ventilation is arranged in a Khrushchev-era building. This allows you to save space and costs during the construction of a building, but has a lot of unpleasant consequences:
- the entry of dust and unpleasant odors from other apartments - residents of the upper floors, where the air rises naturally, are especially susceptible to this;
- rapid contamination of the common ventilation pipe;
- lack of sound insulation.
There are several other ways to exhaust air through ventilation shafts - with horizontal ducts in the attic and pipe outlets into the attic without a chimney. In the first case, horizontal air ducts reduce air draft, and in the second, the attic becomes dirty due to the lack of outlet to the street. The ventilation scheme in Khrushchev and other Soviet-type buildings, although budget-friendly, is inconvenient for residents.
Schematic diagrams of some natural ventilation systems in residential buildings: (a) - without prefabricated ducts; (b) - with vertical collecting channels; (c) - with horizontal prefabricated channels in the attic; (d) - with a warm attic
Fortunately, there is modern system ventilation, which automatically extracts and supplies air. Its design includes a fan that forces air into the shaft. It is usually located in the basement of a building. An exhaust ventilation system of the same power is placed on the roof of the house, which forcefully removes polluted air masses from the air duct. This is the most simple circuit ventilation in an apartment building. It can also be arranged using energy-saving equipment - recuperators. The task of the recuperator is to remove heat (or cold) from the exhaust air and transfer it to the supply air.
Ventilation shafts usually come from the basement multi-storey building, additionally providing its protection from dampness and fumes. Basement ventilation is ensured using natural draft, and in modern houses they install and air supply units. To remove damp air from the basement, common ventilation shafts are used, with openings on each floor and in each apartment.
Ventilation of the basement, the place where the natural ventilation system begins, is one of the main conditions for its proper operation. To do this, vent holes are made in the basement walls, through which fresh air enters the basement. It not only reduces humidity at the base of the house, but also creates draft in the common house shaft.
The shape of the holes can be simple - round or square. They must be placed at a sufficient distance above the ground so that water and dirt from the street do not get inside. Optimal distance from the ground - at least 20 cm. The holes should be placed evenly around the perimeter of the basement; if there are several rooms in it, it is necessary to organize several vents in each. The vents must not be closed, otherwise the entire principle of ventilation will be disrupted. apartment building. To prevent animals from entering the basement, the openings are covered with a metal mesh.
Calculation of apartment ventilation
Natural or artificial ventilation of a residential building is calculated by specialists during the construction of the building, and the residents of the building receive apartments with a “default” ventilation system. It will not be possible to change the design of the ventilation system in a Khrushchev-era building; this will require serious intervention in the structure of the building. However, with the help various devices You can improve air circulation in your apartment. For this it is necessary.
If you are not satisfied with the ventilation in your apartment, you can install additional hoods in the kitchen and fans on grilles in the bathroom. In this case, you should remember the basic rule - the amount of air exhausted should not exceed the amount entering the apartment. In this case, the ventilation systems will work as efficiently as possible. Some models of hoods and fans can operate on air flow - they are worth installing if the room is not ventilated enough through windows and doors.
Particular attention should be paid to the power of exhaust devices, for small apartments A capacity of 50 to 100 m³ of air per hour will be sufficient. To accurately determine what load will be optimal for the device, you can measure the amount of air mass in the room. To do this, the area of the apartment is summed up and multiplied three times. The resulting volumes of air must completely pass through the fans within an hour.
You can organize additional air flow using air conditioners, hoods and fans. Together, these devices will perform the main tasks of room ventilation:
- a kitchen hood will cleanse the room of unpleasant odors, grease and smoke, filling it with clean air;
- fan in the bathroom - remove moist air;
- air conditioner - cools and dehumidifies the air in a room.
These devices will ensure good circulation of air masses in different rooms and regulate their cleanliness - they are simply irreplaceable in the bathroom and kitchen.
The amount of supply air can exceed the volume of exhaust air by 15–20%, but not vice versa.
Home ventilation care
Often, ventilation does not work due to a clogged air duct or outlet grille. You can do it yourself within your apartment by removing the grate and cleaning the pipe walls with a brush, broom or vacuum cleaner. Particular attention must be paid to the mesh covering the entrance to the mine - it acts as a filter on which all contaminants remain.
Complete is carried out by a special service at the request of residents.
First, the performance of the exhaust ducts is diagnosed and a work plan is drawn up. To check the cleanliness of mines, a video camera on a cable is often used - it allows you to determine where dirt accumulates and where the pipe is deformed. 
After this, cleaning of the air duct begins. Professionals use weights, pneumatic brushes, weighted brushes and other tools. Ordinary residents should not engage in such work - this can damage the integrity of the pipe.
Natural ventilation in a multi-storey building is not very effective compared to mechanical ventilation, but it requires cleaning less often. A team of specialists should be called once every few years if there are clear signs of air duct contamination. Automatic ventilation systems experience greater loads and require more thorough cleaning. The maintenance of such systems is often carried out by the companies that install them.
Monitoring the performance and increasing the efficiency of home ventilation is one of the key points in creating a healthy microclimate in your home. By taking a number of measures to improve the ventilation of your home, you will rid yourself of dust, unpleasant odors, and kitchen or bathroom products in the air.
According to current sanitary standards Apartment buildings must be equipped with ventilation, in which polluted air is removed from the kitchen and bathroom, and clean air is supplied to the living rooms.
Ventilation of houses built last century is based on natural draft. Modern residential complexes are commissioned with roof fans and forced air exchange systems. Read on to learn how the ventilation system in an apartment building works, how to clean it and improve it.
The need for ventilation in an apartment building
Doing laundry, washing dishes, and taking a shower releases water vapor into the air. Particles of lint from clothes and carpets, epithelium and pet hairs form dust. During cooking, odors and tiny droplets of fat evaporate.
If an apartment building is not equipped with a ventilation system, all waste products of people remain in the premises. Conditions are created that are dangerous to people’s health and the safety of their property. Mold eats away walls and furniture, and residents suffer from allergies and asthma. Children and the elderly feel the worst in such apartments.
Functions of ventilation in a residential area:
- Ensure the penetration of clean air into apartments;
- Remove dust and other impurities harmful to health along with the exhaust air;
- Regulate humidity in living and utility rooms.
If, when cooking with the window open, odors spread into the adjoining rooms, the ventilation system in an apartment building is not working satisfactorily. Another indicator that the ventilation in the house is not working is the intense accumulation of dust in the corners, on the ventilation grille and under the ceiling. Within a day or two after cleaning, you can notice clouds of dust under upholstered furniture.
Most often, residents of the top floors suffer from this. Poor traction is explained by insufficient distance between ventilation grille in the apartment and the end of the ventilation duct. Normally it should be at least 2 meters. Often this condition is not met due to the presence warm attic in an apartment building, ventilation does not work as intended by the designers.
The principle of air removal into ventilation
Most complaints about the work are caused by ignorance of how ventilation works in a panel house.
There are 2 withdrawal schemes dirty air from apartment buildings:
Scheme 1. The ventilation duct reaches the attic, here it turns into a horizontal duct
Several sealed boxes are combined into one shaft, ending above the roof. With this principle of ventilation in an apartment building, air masses from all floors rush to the horizontal box, from there into the common shaft and onto the street. As the air moves, it hits the surface of the box and an area of high pressure is formed. The air rushes into the nearest hole leading out.
Sometimes the closest exit is the fifth floor ventilation duct. Normally, this should be a common ventilation shaft. Even with the optimal cross-section of a horizontal box, backdraft may occur if the box cover is installed too low. The air is reflected from the lid and “squeezes out” odors coming from below into the kitchens of the top floor. To avoid such an undesirable effect, use 2 methods:
- Method 1. It is necessary to increase the diameter of the horizontal box in the attic by 2.5 times. In addition, “cuts” are installed inside the box. All modifications should be carried out only by trained people. You must first consult with a specialist, since it is not always possible to use this method of improving ventilation;
- Method 2. The ventilation ducts of the top floor are arranged separately and are inserted into the ventilation shaft above the duct. A separate channel should be well insulated.
Scheme 2. All ventilation ducts lead to the attic
The attic space is used as an intermediate chamber. There is a single ventilation shaft leading through the roof.
This method of air exhaust is very common in modern construction.
More often reverse thrust there is no network, but on the upper floors it is very weak. This is explained by the small height of the vertical channel (no more than 40 cm). When the doors of the attic or between sections are open, there is also virtually no air movement.
The standard diameter of air ducts for such a ventilation system for an apartment building is 140 mm. To improve its operation, the channel outlets are lengthened due to pipes placed on them. The joints are sealed. It is enough to add 1 meter of pipe and tilt it slightly in the direction of the central shaft.
Apartment supply and exhaust ventilation
In multi-storey buildings, a supply-exhaust ventilation system is installed in each apartment. The following scheme is usually used: exhaust duct outlets are located in toilets, bathrooms and kitchens, and clean air served through the windows.
So that air can circulate freely throughout the apartment, gaps of 1–2 cm are left under the interior doors.
This plan for the operation of ventilation in an apartment building is quite simple, but not always effective.
If the windows in the apartment fog up, or there is an unpleasant smell from time to time, it is necessary to inspect the ventilation of the apartment building. Often natural ventilation in an apartment building does not work due to blockage. But residents do not have the right to clean the ventilation in apartment buildings. Repair work is also carried out by specialists. So how to clean the ventilation in an apartment?
Professional ventilation cleaning
Specialists clean ventilation in apartment buildings using professional equipment. First, a diagnosis of the ventilation of an apartment building is carried out. As a rule, a video camera is used for this. It detects places where debris, dust, and destruction accumulate. After which the pneumatic brushing machine removes all the dirt. At the same time, the mine can be disinfected.
You can inspect the ventilation of an apartment building in the simplest way: bring a burning candle or match to the ventilation grille. If the flame deviates towards ventilation, then all is not lost. The vertical position of the flame indicates that the natural ventilation in the house is not really working. When inspecting ventilation, it is necessary to check all ventilation grilles in an apartment in an apartment building.
Self-cleaning ventilation
Residents of apartment buildings can dismantle the ventilation grille in their apartment and clean the accessible part of the shaft with a broom or vacuum cleaner.
Before cleaning the ventilation in an apartment building yourself, it is advisable to wear protective equipment: gloves, a respirator, goggles. Sometimes a perfectly serviceable and clean system does not work efficiently.
In this case, you need to resort to additional means:
- supply valves;
- exhaust fans.
They make it possible to regulate the flow and exhaust of air from the apartment, are inexpensive and quite easy to install.
Ventilation of the basement and basement floors
The basement is one of the most important elements ventilation system apartment building. After all, the ventilation shafts that penetrate all floors begin in the basement.
As a rule, ventilation of the basement floor of an apartment building is organized using natural draft.
To remove damp air from the basement, common ventilation ducts are used, leaving openings on each floor and in each apartment.
The flow of fresh air is no less important for ventilation of the basement of an apartment building, where it is often damp and cold. Vents or openings in the walls of the basement, located slightly above the surface of the ground, serve this purpose. The number of vents is calculated based on the area of the building.
The area of the vents is 1/400 of the area of the building.
If the building is located in an area with a high radon content or extreme background radiation, the area of the vents increases to 1/100 of the building area.
The area of one vent can vary from 0.05 to 0.85 square meters. meters.
Vents with a diameter of 30 x 30 cm must be reinforced.
The ventilation holes can be of any shape, but most often they are made rectangular or round. This form is easier to perform and looks better.
Vents should be evenly distributed around the perimeter of the foundation to avoid the formation of unventilated areas.
The distance from the corner to the nearest vent is 90 cm. It is advisable to do even number vents and place them opposite each other. The distance to the ground is at least 20 cm. If the holes are lowered, they may be flooded with rain or spring floods.
The higher the vents are off the ground, the better.
If the foundation of the house has internal load-bearing surfaces, vents should be made in them so that the entire ground floor apartment building.
The vents must not be closed, otherwise the entire principle of operation of the ventilation of an apartment building will be disrupted. To prevent cats and rodents from entering the basement, the openings are closed with a metal mesh.
So, ventilation of an apartment building is unified system, the device of which begins in the basement and ends above the roof. Any attempts by residents to independently interfere with its operation, such as cleaning the ventilation in the apartment, dismantling its elements or remodeling, entail administrative liability!
More information about how the ventilation of an apartment building works video:
The ventilation system of a house is a common property and must be maintained by a management company, to which you pay a lot of money every month under the heading “maintenance and repair of the home.”
This is installed next. documents:
A. “Rules for the maintenance of common property in an apartment building” (approved by the Decree of the Government of the Russian Federation of August 13, 2006 N 491):
… 2. The composition of common property includes:
e) mechanical, electrical, SANITARY AND OTHER EQUIPMENT located in an apartment building outside or inside the premises and serving more than one residential and (or) non-residential premises (apartment);”
B. “Minimum list of services and works necessary to ensure proper maintenance of common property in an apartment building, and the procedure for their provision and implementation” (approved by Resolution of the Government of the Russian Federation No. 290 of April 3, 2013)
“... 15. Work carried out for the purpose of proper maintenance of VENTILATION AND SMOKE EXTRACTION systems in apartment buildings:
- maintenance and seasonal management of equipment for ventilation and smoke removal systems, determining the performance of equipment and system elements;
- monitoring the condition, identifying and eliminating the causes of unacceptable vibrations and noise during operation of the ventilation unit;
... eliminating leaks in ventilation ducts and shafts, eliminating blockages in ducts, eliminating malfunctions of dampers and throttle valves in exhaust shafts, umbrellas over shafts and deflectors, replacing defective exhaust grilles and their fastenings;
... monitoring the condition and restoration of anti-corrosion painting of metal exhaust ducts, pipes, pallets and deflectors;
- when damage and violations are identified - development of a restoration work plan (if necessary), carrying out restoration work.”
V. “Rules and standards of technical operation housing stock"(approved by the Post of the State Construction Committee of the Russian Federation dated September 27, 2003 No. 170):
“… V. Maintenance and repair of engineering equipment
... 5.7. Ventilation
5.7.1. Design temperatures, multiplicities and air exchange rates for various rooms residential buildings must meet established requirements. Natural exhaust ventilation should ensure the removal of the required volume of air from all premises provided for by the project at current outdoor temperatures of 5 degrees. From and below….
5.7.2. Personnel servicing ventilation systems of residential buildings are obliged to:
- scheduled inspections and elimination of all identified system faults;
- replacement of broken exhaust grilles and their fastening;
- elimination of leaks in ventilation ducts and shafts;
- eliminating blockages in channels;
- troubleshooting of dampers and throttle valves in exhaust shafts, umbrellas over shafts and deflectors.
... 5.7.7. Ventilation systems in residential buildings must be adjusted depending on sudden decreases or increases in the current outside air temperature and strong winds.
Engineering and technical workers of housing maintenance organizations are required to instruct residents on the rules for regulating ventilation systems.
5.7.8. It is not allowed to seal exhaust ventilation grilles or cover them with household items, or to use them as fastening lines for drying clothes….
5.7.9. The heads of central exhaust shafts for natural ventilation must have umbrellas and deflectors.
… 5.7.11. The list of deficiencies in the ventilation system TO BE CORRECTED DURING REPAIRS of a residential building should be compiled on the basis of data from the spring inspection...
Appendix No. 4 (recommended)
LIST OF WORKS ON MAINTENANCE OF RESIDENTIAL BUILDINGS
Work performed during technical inspections and walk-throughs of individual elements and premises of residential buildings
…6. Checking the presence of draft in the smoke ventilation ducts.
Appendix No. 7 (recommended)
LIST OF WORK RELATED TO CURRENT REPAIRS
… 14. Ventilation
REPLACEMENT AND RESTORATION OF OPERATIONALITY of the intra-house ventilation system, including the fans themselves and their electric drives.”
G. MDK 2-04.2004 “Methodological manual for the maintenance and repair of housing stock” (approved by order of the USSR State Construction Committee in 2004):
“... 4.3.6. The housing maintenance organization must:
- maintain ventilation ducts and chimneys in technically good condition;
... 4.3.7. Work to eliminate construction defects, ELIMINATE CHANNEL TRACTION VIOLATIONS IDENTIFIED DURING ROUTINE INSPECTIONS, as well as finishing work after installation or repair internal devices gas supply MUST BE CARRIED OUT BY THE HOUSING SERVICE ORGANIZATION.
... 4.3.12. HOUSING MAINTENANCE ORGANIZATIONS ARE RESPONSIBLE for the technically sound condition of ventilation ducts. During any work, it is not allowed to eliminate ventilation ducts in kitchens and other rooms equipped with gas heating appliances. In progress maintenance housing stock, they must ensure periodic inspections of the suitability of ventilation ducts and chimneys for use within the following periods:
... b) ventilation ducts of rooms in which gas appliances are installed - at least twice a year (in winter and summer).
Repairs of chimneys and ventilation ducts may be carried out by personnel of a housing maintenance organization who have the appropriate specialty and training, under the supervision of an engineer and technical worker.
... 4.3.13. Unauthorized repairs, alterations and extensions of chimneys and ventilation ducts are not allowed. Inspection and cleaning of chimneys and ventilation ducts must be REGISTERED. After each repair, chimneys and ventilation ducts are subject to inspection and cleaning, regardless of the previous inspection and cleaning within the time limits established in the acts.
Appendix 2
LIST OF WORK INCLUDED IN THE HOUSING REPAIR FEE ( current repairs)
... 14. Ventilation:
changing individual sections and eliminating leaks ventilation ducts, mines and chambers;..."
Description:
The book reveals basic principles designing ventilation systems for multi-storey buildings, it presents methods for determining the required air exchange in rooms and calculations of air infiltration through leaks in fences, describes and evaluates the ventilation systems of multi-storey residential buildings, and provides technical, economic and operational indicators of these systems.
Features of ventilation of high-rise residential buildings
The report was based on materials from the book by I. F. Livchak “Ventilation of Multi-Story Residential Buildings,” which was published in 1951 by the State Publishing House of Architecture and Urban Planning.
The book reveals the basic principles of designing ventilation systems for multi-story buildings, it presents methods for determining the required air exchange in rooms and calculations of air infiltration through leaks in fences, describes and evaluates the ventilation systems of multi-story residential buildings, and provides technical, economic and operational indicators of these systems.
Despite the fact that the book was published in 1951, it remains relevant to this day - because today issues related to indoor air quality comfortable parameters microclimate of buildings and premises are of particular importance.
In this issue of the magazine we publish one of the chapters of this book - “Features of ventilation of high-rise residential buildings,” which was written by I. F. Livchak together with engineer T. A. Melik-Arkelyan.
High-rise buildings include houses above 15 floors, which, as a rule, have technical floors that divide the building in height into zones up to 10–12 floors high.
Technical floors have hermetic ceilings and partitions with hermetically sealed doors on the staircase, preventing the flow of air from the floors of the underlying zone to the floors of the upper zone.
The high height of the building and its planning and operational features have a significant impact on the operation of ventilation. The main factors that must be taken into account when designing high-rise residential buildings include the following:
1. The possibility of increased air flow in winter from the lower floors to the upper ones due to the high height of the building and the influence of those located above each other friend zones. This position creates increased infiltration of outside air into the lower floors of the zone.
2. Increased wind speeds at higher altitudes from the ground. This creates increased infiltration of outside air into the windward areas of the upper floors.
3. Increased gravitational pressures in the ventilation system due to the high height of the building, reaching up to 20 mm of water in 30-story buildings. Art. at t n = -15 °C and falling to 7 mm water. Art. at t n = 5 °C versus 5–2 mm water. Art. V multi-storey buildings mass construction.
The magnitude of the available pressures makes it possible to use them as a good stimulator for traction at low outside temperatures. At the same time, significant fluctuations in pressure can create significant unevenness in ventilation operation.
4. Significant length of air ducts and therefore large hydraulic losses in them, which causes a decrease in the efficiency of deflectors in exhaust shafts.
5. The impossibility of ventilating sanitary facilities in the summer due to the lack of windows in them, as a rule.
To the noted factors it should be added that high-rise buildings, unlike ordinary mass-produced buildings, are equipped with complex engineering equipment: vacuum cleaners, their own telephone exchanges, garbage disposal, elevator facilities, water supply and heating pumping units etc.
It's complicated engineering equipment necessitates the maintenance of technically qualified operating personnel, who can also be used in the operation of ventilation systems of a residential building.
Therefore, for the buildings under consideration, mechanical ventilation is quite possible.
1. Selection of ventilation system
Sanitary facilities
The impossibility of ventilating sanitary facilities through windows and the ineffective operation of deflectors lead to the need for installations in sanitary facilities of high-rise buildings exhaust ventilation with mechanical motivation, because otherwise for a long period, at outside temperatures of 10–15 °C and above, when there is no gravitational pressure, these rooms will remain without ventilation.
For example, in Moscow, the average number of days with temperatures above 15 °C, according to long-term climatological observations, is 75.72; they occur mainly in May, June, July, August, September and partly October. (In April, only 0.3 days have temperatures above 15 °C, and in October - 3.5 days.)
Kitchens ventilated by a common ventilation system with sanitary units are the main source of the formation of harmful emissions. These emissions, when opening kitchen windows located on the windward side, can spread into the living rooms. Therefore, kitchens should also be equipped with mechanical ventilation.
Ventilating the kitchen and sanitary facilities with common exhaust systems will only simplify the ventilation system of the building as a whole.
Mechanical stimulation in exhaust ventilation will make it possible to design ventilation systems with increased resistance to air passage, which will reduce the negative impact of changes in gravitational pressure.
So, for example, considering the performance of the ventilation system to be proportional to the square root of the effective pressure and the design resistance of the system is 30 mm of water. Art., we get an increase in productivity for a 30-story building when the outside temperature changes from +5 to –5 °C in
| 30+20 | =1.15 times | |
| 30+7 |
If the calculation were carried out only on natural impulses when outside temperature 5 °C, then the corresponding increase in system performance would be
| 20 | =1.7 times | |
| 7 |
Such an increase in productivity (if the pressure is not regulated by throttling) would lead to excessive air exchange in the rooms, excessive fuel consumption or overcooling of the premises.
Significant resistance exhaust system Mechanical ventilation will also help reduce excess infiltration in windward rooms. With little resistance in the system, the outside air infiltrating into the rooms will flow relatively freely into the exhaust ventilation, as a result of which the pressure inside the room will drop, and the pressure difference on both sides of the windward window will increase, which in turn will increase the infiltration of outside air.
Such a system will be most effective in windward apartments without cross ventilation located on high altitude, at high wind speeds.
Thus, the need for mechanically driven exhaust ventilation from kitchens and sanitary facilities is quite obvious.
Living rooms
When analyzing work ventilation devices In houses of mass construction, the presence of exhaust ventilation with natural impulse only from sanitary facilities (in the absence of such in living rooms) was considered insufficient.
If there is a guaranteed mechanical impulse on the exhaust from the sanitary units, a fan that develops a sufficiently high pressure can create the necessary vacuum in the apartment and suck in outside air through the cracks window openings and thus ensure the required ventilation air exchange in living rooms.
However, with such a system, blowing from windows is inevitable, especially when low temperatures outside air.
In addition, the lack of special ventilation devices in living rooms can lead to disruption of normal temperature conditions.
Rooms with more breathable window sashes will increase air exchange at the expense of reduced air exchange in rooms with less breathable sashes.
Thus, stable air conditions in living rooms cannot be ensured, and they will depend on many random reasons. Therefore, you should not leave living rooms in high-rise buildings without special ventilation devices for inflow.
The simplest ventilation device for an organized flow of air into living rooms is the installation of firecrackers in the outer walls under the ceiling of the room. However, this does not exclude blowing in the room, and, in addition, the holes of the “firecrackers” coming out of each room onto the outer surface of the wall will spoil the facade of the building.
A more advanced device is the so-called window sill device, shown in Fig. 1 and 2.
Here, the air intake is carried out through a gap under the metal fender of the window opening, 2.5 cm high. Such a gap is completely invisible from the outside.
Air passes over heating device along box 3 made of thin stainless steel measuring 60 x 2.5 cm at the end of the box the air hits vertical wall movable valve 2 and exits into the room in the direction from top to bottom. When entering the room, the supply air mixes with the currents of rising warm air from the heating device, as a result of which the blast is significantly reduced.
The advantage of a window sill supply unit is the ability to regulate the amount of supply air, achieved by changing the width of the gap through which air enters the room. The gap is adjusted by a valve that moves in one direction or another when adjusting screw 1 in rack 4 is rotated.
In Fig. Figure 3 shows another device for a decentralized flow of outside air into a room with its heating by a heating device.
Air intake is also carried out under the metal window visor. Next, the air is directed downwards, here it mixes with the air in the room, rises up, touching the radiator, heats up and goes out into the room.
In Fig. Figure 4 shows the possible positions of the control valve, with the help of which (if necessary) you can regulate the degree of heating of the incoming air.
The supply window sill device is much simpler than the device discussed above for supplying air with heating by a heating device (Fig. 3).
The weak point of the latter is the narrow valve through which the air flows down. Dampness may form in it; In addition, this channel will become clogged over time, and cleaning it turns out to be impossible.
Cleaning the window sill supply unit (Fig. 2) from dust does not cause any particular difficulties.
All considered options for decentralized inflow have general disadvantages: in them, supply air enters the premises without necessary cleaning. Cleaning is necessary even for the upper floors, because in large industrial centers, even at high altitudes, the outside air, especially in winter period, turns out to be quite dusty.
The second disadvantage of decentralized inflow is the unevenness of its operation due to the action of wind.
Excessive pressure and vacuum that arise under the influence of wind at the outer surface of the building and, consequently, at the intake openings of the supply devices will increase and decrease the amount of supply air.
To reduce the effect of wind speed, special canopies are installed on the outside of the ventilation holes. However, this event does not bring significant results, because... vent remains unprotected from static pressure generated by wind.
Unevenness of air flow can be significantly reduced by increasing the resistance to air passage in the hole.
So, if the resistance of the inlet opening is taken equal to 0.5 mm water. Art., then the additional pressure on the outer surface is about 0.25 mm water. Art., formed, for example, by a wind speed of 3 m/s with an aerodynamic coefficient of 0.5, will increase the amount of supply air through the hole in
| 0,5+0,25 | =1.15 times | |
| 0,5 |
Thus, in a room where there is a decentralized inflow, a vacuum of about 0.5 mm of water should be maintained. Art., which is usually achieved by exhaust ventilation. Exhaust ventilation and the device for decentralized inflow must be adjusted to this value.
Work decentralized air supply device at higher resistance is undesirable, because this causes an increase in vacuum in the apartment, which leads to significant unorganized air leaks through the cracks of the windows.
It is appropriate to note here that in order to ensure the suction of fresh air through window sill cracks in living rooms, in buildings equipped with exhaust ventilation and decentralized inflow, it is necessary to achieve the greatest possible sealing of windows, especially in kitchens.
More perfect is centralized supply system, because it is free from the indicated disadvantages of decentralized air flow into living rooms. It is centralized supply ventilation with mechanical drive that should be recommended for living rooms in high-rise buildings, although the construction of such a system is more expensive than the installation of a decentralized supply.
Mechanical urge in supply ventilation makes it possible to provide centralized cleaning of outside air in the supply chamber.
Increased resistance of the supply ventilation system, possible due to mechanical stimulation, will reduce the adjustment required when there is a variable temperature difference between the outside and inside air.
It is possible to equip living rooms with supply and exhaust ventilation, providing each room with supply and exhaust from centralized supply and exhaust systems. However, such a solution cannot be considered economically feasible, since it, in addition to a significant increase in one-time costs for the construction of ventilation and its complication, will also increase operating costs due to an increase (approximately doubling) in the total air exchange in the apartment.
2. Calculation features
The amount of fresh air entering the premises of high-rise residential buildings with the same population density should be the same as in residential buildings of mass construction. However, the infiltration of fresh air, due to increased wind speed at high altitudes and the influence of zones located one above the other, is different in high-rise buildings.
The intensity of infiltration depends on the wind, temperature difference, the tightness of the enclosing structures and many other factors, and for each building, depending on its planning features, the intensity of infiltration will be different.
According to approximate calculations made by the authors, for three- to four-room apartments without cross ventilation, equipped with supply and exhaust ventilation and double apartment doors, in a 30-story building divided into three equal zones, outside air infiltration at an outside temperature of -5 ° C and average speeds wind is expressed by the following average values:
First zone (up to 40 m from the ground): wind speed 2–3 m/s; the average exchange rate created by infiltrating outside air is 0.25, with an increase in the lower floors to 0.3 and a decrease in the upper floors to 0.2 rpm.
Second zone (40–80 m): wind speed 3–4 m/s; the average exchange rate is 0.35 rpm/h, with an increase in the lower ones to 0.4 and a decrease in the upper ones to 0.3 rpm/h.
Third zone (80–120 m): wind speed 4–5 m/s; the average exchange rate is 0.45 rpm, with an increase in the lower floors to 0.5, and in the upper floors to 0.4 rpm.
The frequency of air exchanges in living rooms created by supply and exhaust ventilation (given the above data) should be as follows:
In the first zone:
On the lower floors:
1.25 – 0.3 = 0.95 rpm;
On the upper floors:
1.25 – 0.2 = 1.05 rpm.
In the second zone:
On the lower floors:
1.25 – 0.4 = 0.85 rpm;
On the upper floors:
1.25 – 0.3 = 0.95 rpm.
In the third zone:
On the lower floors:
1.25 – 0.5 = 0.75 rpm;
On the upper floors:
1.25 – 0.4 = 0.85 rpm.
In all intermediate floors of each zone, the exchange rate can be determined by interpolation, rounded to 0.05 rpm/h. Thus, the air exchange value for living rooms of a multi-story high-rise building is determined within the range of 0.75–1 rpm, which is recommended by temporary technical conditions.
The frequency of exchange in kitchens and sanitary facilities should be the same as in residential buildings of mass construction. The amount of air extracted and supplied to the apartment should be the same.
The initial value for determining the cross-section of the supply and exhaust ventilation channels in high-rise buildings should be considered the speed of air movement, which is taken in such a way that if the fan is inactive, the system can work on natural impulse. For these reasons, it is advisable to have a radius of action of the ventilation system of no more than 10–12 m.
To increase the resistance of the ventilation system during normal operation with an active fan, a damper or throttle valve should be installed on each supply and exhaust duct. These control devices are installed in close proximity to the ventilation grille or at the junction of a group of ducts.
The selection of supply and exhaust ventilation fans is made by pressure depending on the height of the building: for 20 floors, at least 20 mm of water. Art., with 30 floors in at least 30 mm of water. Art. etc.
Otherwise, the calculation of ventilation devices has no special features and is carried out in the usual way.
3. Design of the system
To reduce the number of ventilation chambers in high-rise buildings, it is allowed to connect apartments located in different zones to one chamber.
For natural ventilation to work, the supply chamber is located below, and the exhaust chamber is located above the serviced premises. Ventilation chambers can be located in the basement, technical floors and attics. In order to prevent draft overturning when the system operates on natural impulse, the ejection of air from exhaust systems serving interconnected rooms must be at the same level.
The installation of independent ventilation ducts from the chamber to the ventilated room in high-rise buildings with a large number of floors causes serious difficulties. Therefore, the following combinations of supply and exhaust ducts are allowed:
a) serving living rooms - in one horizontal channel within one apartment;
b) serving bathrooms and toilets - in one horizontal channel within one apartment;
c) vertical channels - into one collection channel within one zone.
It is also possible to combine vertical exhaust ducts from homogeneous premises within the zone into one duct with a break through two floors, as is schematically shown in the section of the building shown in Fig. 5. Such a merger can be allowed in exceptional cases, because when unfavorable conditions Air flow may occur from one apartment to another. In any case, such a combination of channels serving rooms facing opposite sides should not be allowed.
It is recommended to place vertical supply and exhaust ducts mainly in walls or in special shafts made of fireproof materials.
As materials for air ducts, it is allowed to use slag concrete - for channels of large cross-sections and gypsum - for dry air in a dry place; asbestos-cement channels are allowed provided they are protected from destruction in a fire.
The use of metal air ducts is not recommended. In Fig. 6, 7 shows an example of a solution for supply and exhaust ventilation of 48 apartments located between two staircases A 24-storey building, divided into three zones.
Heating of the supply air, carried out in the supply chamber, can be done with a plate heater or a heater made of smooth radiators or pipes. A plate heater is more compact than a heater made from smooth radiators or pipes, but its resistance is much greater, which eliminates the possibility of heating the air when the fan is inactive, when the ventilation system operates on natural impulse.
The heaters should be installed in such a way that the entire surface can be cleaned of dust.
Air is purified from dust using oil paper or fabric filters. The first ones, more difficult to operate, give better cleaning than the second ones, easier to use.
It should be noted that the air resistance when passing through the filters reaches 10 mm of water. Art., which excludes the possibility of normal operation of the system when the fan is inactive.
If outside air is taken in for ventilation at a height of more than 50 m, then special cleaning of it from dust is not necessary.
The channel diagram of both the supply and exhaust ventilation systems must provide for the possibility of air passing, in addition to the fan, through a bypass valve, so that if the fan is inactive (an accident or a temporary break), the system can operate on natural impulse.
To reduce noise, it is recommended to install fans with a motor on the same axis, and if this is not possible, on a textural transmission. Wheel peripheral speed centrifugal fans should not exceed 18 m/s when installed in the basement and 15 m/s when installed on technical floors.
In addition to the above restrictions, to prevent noise transmission, it is recommended to install an independent foundation under the fan and motor, not connected to the walls of the building, install sound and vibration insulating gaskets between the foundation and the fan, and connect the fans to air ducts using elastic pipes. To eliminate the transmission of sound through the air duct, sound silencers are installed in the air ducts.
For easier maintenance large number located in different places For ventilation units, it is recommended to concentrate push-button starters of all electric fans in one control center. There, it is necessary to include devices in the electrical circuit to control the operation of the fans.
It is advisable to have instruments in the control center that indicate the temperature and humidity of the supply air entering the chambers.
To inspect and clean ventilation ducts, it is recommended to install special inspection hatches in them.
It is most advisable to place hatches in technical floor, in the attic or in the lower floor, where the vertical ducts join the common prefabricated air duct.
Installation adjustment valves are installed on the vertical ducts at the point where they are connected to the prefabricated air duct.
The laying of ventilation ducts and the installation of supply exhaust grilles in high-rise residential buildings is carried out in the same way as for residential buildings of mass construction.
