Centralized ventilation. decentralized ventilation. Warehouse and logistics complexes

There are two main features of objects of large area and volume regarding their effective ventilation. The first of them is obvious and is associated with the problems of organizing air exchange, which ensures a uniform distribution of fresh air. supply air by the area of the room or in its individual microclimatic zones.

At the same time, an important point is also the rational use of thermal energy along the height of the room, in order to avoid large vertical temperature gradients, when superheated air accumulates under the ceiling, significantly increasing heat loss through the roof, instead of forming the necessary temperature regime in the work area.

The second feature is related to the fact that such objects, being very expensive, during their life cycle in some cases change their purpose several times due to changes in the intended use, technology of work performed, or reorganization of the modes of buildings in operation.

For example, a production machine shop can be converted into a social building. At the same time, it is desirable to preserve the existing ventilation system, limiting itself to organizational and structural reconfiguration at the level of the control system in order to avoid its radical reconstruction.

At the same time, it should be borne in mind that the objects under consideration can fundamentally differ from each other in terms of the requirements for microclimatic support systems. In this sense, supermarkets and hypermarkets differ significantly from pharmaceutical warehouses.

A trade fair complex, for example, has different ventilation requirements than pulp and paper mills, etc. At present, ventilation equipment is available (Fig. 1) that meets the indicated, seemingly incompatible features of the objects of the type under consideration.

Central and decentralized systems

When developing design solutions, one should distinguish between central and decentralized ventilation systems. The first of them assumes the presence of a high-capacity unit that processes air, which is then distributed using a duct system throughout the volume of the room.

The second ones are a set of physically autonomous units of relatively low productivity, located with a certain degree of uniformity over the area of the room directly under the ceiling. Decentralized systems, having a high adaptability, best meet the features of objects of large area and volume.

At the same time, as calculations show, as well as existing practical experience, decentralized systems are more economical in operation, providing a payback period for additional capital costs within 2-3 years, after which they begin to generate net profit. On fig. 2 shows a ventilation unit equipped with a recuperative plate heat exchanger, a heater and a direct cooling system with a condensing unit located on the roof.

Previously, decentralized systems were mainly used in industrial facilities. At present, thanks to the positively proven technical properties and positive economic indicators, decentralized ventilation is also being successfully implemented at social and utility facilities.

These include, for example, super and hypermarkets, markets, railway stations, major airports, sports complexes, exhibition halls, covered garages, etc. The main advantages of using such systems are as follows:

No need to use exhaust and/or supply air ducts.
Significantly reduced static head losses.
Possibility of realization of modes of supply of both heated and cooled air.
Absence of drafts (increased air mobility) in the working area.
Reducing the temperature gradient along the height of the room in the mode air heating.
Possibility of formation of various microclimatic zones within the given areas of one building volume.
The stability of the maintained microclimatic parameters, regardless of external dynamic influences (opening doors and windows, wind loads, etc.).
High reliability of the system as a whole. In the event of a temporary failure of a single unit, the system continues to function, being integrated at the top hierarchical control level. For the period of restoration work, the address of the defective unit is systematically blocked in the general list with subsequent removal of the blocking upon completion of the repair.
High energy efficiency due to improved air exchange, air recirculation and heat recovery, which helps to reduce equipment depreciation due to low operating costs.
No need to use supply and exhaust ventilation chambers.
Possibility of installation without stopping the main technological process;
Possibility of stage-by-stage equipment of the ventilation system by sequential expansion of both functionality and serviced production areas.

Decentralized ventilation systems are limited by the possibilities of their implementation in rooms with a ceiling height of 4.5 to 18 m and an area of less than 100 m2. This is due to the aerodynamic features of the formation of vertical supply jets operating on the principle of air injection with a controlled swirl angle and a rarefaction core formed directly behind the nozzle exit.

Exhaust air contaminated with oils

One of the advantages of decentralized systems lies in the possibility of choosing ventilation units from a wide range of supplied models that meet the specific requirements of their application. In some cases, a significant problem is the presence of oil aerosol in the exhaust air.

Standard technical solutions in these circumstances turn out to be unacceptable due to the need for frequent replacement of filters and the destruction of sealing materials that are not sufficiently resistant to oils.

The oil-resistant models available as part of the supplied ventilation units provide a solution to this problem, having the ability to effectively capture oil aerosols and adequately drain their filter products.

Working in cold climates

For Russia, the efficiency of the units is of particular importance when low temperatures, since a number of regions are located in the northeastern part, characterized by particularly harsh climatic conditions. According to SNiP 23-01-99 "Construction climatology" in the area of the pole of the course (Oymyakon), the estimated temperature of the coldest five-day period with a probability of 0.98 is -60°C. The standard version of the units allows their operation at outdoor temperatures down to -30°С.

The special version Cold Climate (CC-1) extends the operating limit of the units to -40°С, and the version Cold Climate (CC-2) - up to -60°С. The design of these units uses plastics that retain strength at low temperatures and do not crack in the cold. Instead of rubber shock absorbers, steel springs with silicone cups are used.

All sealing profiles are made of cold-resistant silicone. Air valve actuators are equipped with heating systems. Spring return actuators are installed for protection in the event of a power outage. The plate heat exchanger is sealed using a highly durable epoxy resin.

If the heat exchanger begins to freeze, the differential pressure differential sensor is triggered and the following sequence of actions starts: the outside air damper closes and the recirculation damper opens; the supply fan stops and the exhaust fan continues to operate; the bypass valve of the plate heat exchanger opens fully; warm air flow on the hood melts the ice and after an adjustable time delay and return differential sensor pressure drop to the initial state, the unit again switches to normal operation. Frost protection of the air heater is carried out using a controller that monitors both the air temperature and the water temperature.

For this purpose, the end of the capillary tube stretched on the reverse side of the heater is inserted into the drain pipe. If the water temperature drops below 11°C, mixing valve gradually opens. When the temperature drops to 5°C, the mixing valve is fully open and Emergency Signal freezing. When starting the unit and when switching from recirculation mode to one of the supply modes fresh air the system of smooth switching on of the supply fan is activated.

To ensure operation at outdoor air temperatures below -40°C (version CC-2), exhaust fan motors are additionally equipped with heating devices for periods of fan shutdown, which guarantees reliable start-up and operation of the unit at temperatures down to -60°C.

Work in explosive and flammable environments

In the presence of assigned categories of explosion and fire fire hazard A and B, regulated in accordance with the norms of NPB 105-03 "Determination of the categories of premises, buildings and outdoor installations for explosion and fire hazard", it is prohibited to use standard ventilation units located indoors for air heating purposes.

For these purposes, it is possible to use the specified units in a special EEX version, which, in accordance with the European standards DIN EN 60079-10 and VDE 0165 (part 101:1996-10), is certified for operation in zones 1 and 2. The indicated means that the units can be used in this execution when equipping rooms in which it is possible to form a flammable and explosive environment of class T3, which corresponds to an ignition temperature of combustible substances of more than 200 ° C.

The maximum allowable temperature of hot surfaces in this case is 200°C, which is according to GOST 51330.0-99 “Explosion-proof electrical equipment. General requirements» refers to explosion protection group II T3. The main differences between EEX and standard ventilation units are as follows:

electrical components are replaced with explosion-proof ones;
electrical circuits have the necessary galvanic isolation;
materials capable of accumulating electrostatic charges are suitably protected or completely replaced.

In particular, the following activities have been carried out:

Fans are replaced with explosion-proof diagonal ones. The fan motors are equipped with PTC type temperature sensors with trigger protection device. The fan inlet is made of of stainless steel and has a protective grille.
The contactor box is equipped with Ex cable glands with integral sealing ring and screw clamping device.
The sound-absorbing coating of the disc flow divider is pasted over with aluminum foil in order to prevent the accumulation of electrostatic charges, which is appropriately grounded.
Pocket type filters have an interwoven metal mesh that is grounded. The metal frame of the filter is also grounded.
The filter differential pressure sensor is mounted inside the control section but not connected. Electrical connection is provided to the control cabinet during installation of the unit at the customer's site using an external galvanic isolation circuit.
The freezing thermostat is mounted in the heater section, but also not connected. Electrical connection is provided to the control cabinet during installation of the unit at the customer's site using an external galvanic isolation circuit.

In general, the units meet the requirements of GOST R 51330.13-99 “Explosion-proof electrical equipment. Electrical installations in hazardous areas" and Manual 13.91 "Fire requirements for heating, ventilation and air conditioning systems" to SNiP 2.04.05-91* "Heating, ventilation and air conditioning".

Comfortable environment in shopping centers increases sales

In the general range of units supplied, there are special models designed for equipment shopping centers(Fig. 3), the specificity of which is associated with the following circumstances:

Low ceiling height.
The need for minimal disruption to the interior.
Increased requirements for noise performance.

The special models of ventilation units mentioned above are structurally designed in such a way that only injection-type air distributors go into the sales area. Thus, the interior is preserved and the distance from the nozzle exit to the upper boundary of the working area is increased, which allows both heated and cooled air to be supplied into it without excessive mobility (drafts).

Since the fans are located above the roof, and the air distributor has a disk flow divider lined with a porous material that shields the penetration of sound into the hall, noise impacts are minimal. As a result, a high level of comfort is achieved, which attracts customers, contributes to their longer stay in the shopping center and increased purchases.

Consider installation and maintenance

Ease of installation and maintenance, as well as the required volume of these works are one of the indicators that characterize the ventilation system. Design solutions that provide for a decentralized ventilation system are implemented in the shortest possible time with a small volume installation work, since the supplied monoblocks go through a full cycle of assembly work at the factory.

The absence of air ducts and, accordingly, pressure losses to overcome aerodynamic resistance, which usually requires up to 80% of the consumed electrical energy, leads to the fact that the power of the electric motors is small (maximum 3 kW) and the supply cables have a small cross section. As a result electrical installation is greatly simplified.

Hydraulic piping is also simplified by the complete delivery of the hydraulic module in assembled form, which includes a three-way solenoid valve, as well as the necessary shut-off and control valves (balancing, air, shut-off, shut-off valves). The module is equipped with standard fittings on the inlet and outlet pipelines.

The binding of the automation system is reduced to a serial connection of the ventilation units to each other using a standard twisted pair. All work on network configuration is performed from the keyboard of a computer connected as one of the network nodes to a common bus. The three-level hierarchy created in this case is determined in a virtual way by assigning corresponding addresses to the network elements.

Mechanical installation units providing fresh air supply is carried out with outside roofs, which allows you to work in as soon as possible without stopping ongoing production. The same applies to operational maintenance, the volumes of which are reduced to a minimum and are produced without disrupting the progress of the main technological operations.

Each unit serves an individual area, which allows the formation of zones with different temperature settings (comfort ventilation, standby heating, etc.), assigned operating modes (recirculation, fresh air supply, etc.) and different time schedules (single, two- or three-shift work).

The principle of flooding the working area with supply air, supplied and removed in compliance with a certain air balance for each of the individually serviced areas, prevents undesirable flow of polluted air between them. The air supply directly to the working area also increases the efficiency of the assimilation of harmful emissions, actually reducing the concentration of gas and aerosol pollution to a minimum.

Profitable solution

Conceptually, decentralized ventilation in a number of applications is the optimal technical solution, providing not only functional advantages compared to centralized systems, but also more cost-effective, especially in terms of full life cycle operation of the equipment.

Decentralized ventilation has proven itself on the positive side in numerous domestic and foreign facilities. Among Russian facilities, the most characteristic are large customs warehouses finished products, spare parts, materials, semi-finished products, equipment, pharmaceuticals, etc.

They also include sports complexes, exhibition centers, showrooms, concert halls, large printing houses, hangars, equipment repair shops, carpentry and machine shops, etc. one;

Objects of large area and volume impose increased requirements on ventilation systems. Rice. 2;

The ventilation unit with built-in recuperative plate heat exchanger reduces operating costs to a minimum.

The best solution for ventilation of a private house is a system of centralized forced supply and exhaust ventilation with heat recovery.

The basis of the system is a ventilation unit equipped with fans, a heat exchanger - heat recuperator, control devices, filters, etc.

In a house with forced ventilation, air circulation occurs in the same way as in buildings with natural ventilation. Fresh air from the street is supplied to living rooms Houses. Further, the air is directed through the overflow openings in the doors to the kitchen, bathrooms, dressing rooms, pantries. From these rooms, the air is expelled through the exhaust ducts to the street.

Each room of the house must be equipped with either an exhaust or forced ventilation duct. In some cases, both channels are equipped in the room.

The only exception is boiler room ventilation, a fire hazardous room in which a gas boiler is installed, must be carried out using separate isolated channel of natural ventilation. This is due to the need to exclude the flow of combustible gases and fire through the ventilation channels from the boiler room to other rooms.

From block forced supply and exhaust ventilation(PPVV) fresh air from the street through the supply channels enters the living rooms of the house. Further, the air flows into the utility rooms - the kitchen, bathrooms, dressing rooms and others. From utility rooms air is returned through the exhaust ducts back to the PPVV unit.

Two air ducts come from the premises of the house to the forced supply and exhaust ventilation unit (PPVV unit).

Fresh air from the street through the air intake enters the PPVV ventilation unit, and from there through the supply air ducts to the rooms of the house. Further, through the overflow holes in the doors of the premises, the air moves to the utility rooms - the kitchen, bathrooms, dressing rooms. Polluted air is returned from utility rooms through exhaust air ducts to the PPVV unit.

In winter, two air streams, warm from the premises and cold from the street, meet (but do not mix) in the heat exchanger - the heat exchanger of the PPVV unit. The warm outgoing air gives off heat to the air entering the house. Fresh heated air enters the premises. A heat recuperator saves up to 25% of the energy used to heat a house compared to a system without a recuperator.

The ventilation unit, as a rule, is equipped with various devices for air preparation. Filters clean the air from dust, allergenic plant pollen, insects. The air supplied to the house can be humidified, heated, cooled. The centralized system is easily amenable to automation of management and control over its serviceability and mode of operation.

Increasingly, air is taken into the system through ground heat exchanger. This is a pipe laid in the ground below the freezing depth (1.5 - 2 m.). One end of the pipe is connected to the air intake of the ventilation unit, and the other open end is brought out above the ground surface. Passing through the pipe of the soil heat exchanger, the air is heated by the heat of the earth in winter, and vice versa in summer it is cooled. Heating and air conditioning costs for a house with a ground heat exchanger can be reduced by another 25%.

The principle of the device of the heat exchanger of the ventilation system. 1 - warm air from the room; 2 - air to the street; 3 - air from the street; 4 - heated air into the room; 5 - heat exchanger; 6 and 7 - fans.

The cost of a forced ventilation system with a heat recuperator is at least 4-5 times higher than the cost of the device natural system ventilation. The most expensive element of the system is the recovery unit.

The forced system constantly consumes electricity to run the fans. Costs are required for periodic replacement of filters and cleaning.

However, the savings in thermal energy and savings in heating costs pay off all costs. Moreover, the more severe the climate and the longer the heating season, the faster.

In addition, the increased comfort of living in the house, the same is worth something.

Centralized forced ventilation with a heat recuperator in a private house is a system:

provides the necessary air exchange in all rooms at home, regardless of atmospheric conditions;
allows you to easily regulate and automate air exchange in a wide range of changes in air volume and depending on various indicators of the microclimate in the premises;
prepares the fresh air supplied to the premises: filtration, heating or cooling, humidification or dehumidification;
saves a significant amount of thermal energy due to the use of a heat exchanger - heat recuperator of the exhaust air;
consumes electricity to operate the fans;
complex technical device, the elements of which can fail;
stops working in the absence of electricity;
requires qualified installation and periodic maintenance;
creates noise - requires special measures to reduce noise;
constantly monitors the serviceability and efficiency of work (air exchange, temperature and humidity);

The modern energy-saving house is increasingly reminiscent of a sealed plastic container.

To survive in such a house - a container, a centralized supply - exhaust ventilation in the house is simply vital.

It is time for Russian developers to understand this as well.

The air saturated with pollution, moisture and heat also passes through the ventilation unit and is thrown out through the deflector on the roof of the house.

Such an air circulation scheme allows you to create some excess pressure in the living quarters, which prevents the penetration of pollution into the rooms, both from the outside - for example, and from other rooms and spaces inside the house.

The air supplied to the rooms moves to the rooms with intake grilles of exhaust ventilation through the overflow openings in the doors. This is usually the gap between the floor and the door.

In winter, in a heat exchanger - a heat exchanger installed in the ventilation unit, the air emitted from the house transfers part of the heat to the fresh but cold air injected into the rooms.

In rooms where a heating boiler or a fireplace with open cam combustion, using air from the room for combustion, be sure to start both channels of forced ventilation - supply and exhaust channels. The presence of only one exhaust duct is unacceptable, since the vacuum created in the room by forced exhaust can lead to overturning of the draft in the chimney and the entry of combustion products into the room.

Kitchen hood draws money

When turning on the cooker hood thrown out into the street a large number of warm air for the sole purpose of removing odors and other contaminants that form above cooker.

To eliminate heat loss, it is advantageous to abandon the usual kitchen hood. Instead of a hood, an umbrella is installed above the stove, equipped with a fan, filters, odor absorbers for deep air purification. After filtering, the air purified from odors and pollution is sent back to the room. In addition, this solution reduces the performance requirements of the ventilation unit. Such an umbrella is often called a filter hood with recirculation. It should be borne in mind that the savings from lower heating costs are somewhat leveled due to the need to periodically replace the filters in the hood.

Forced ventilation unit in a private house

The supply and exhaust ventilation unit is a rectangular case several tens of centimeters in size.

There are two electric fans in the case.— inlet and exhaust systems ventilation. Fans can operate at different speeds, thereby changing the intensity of air circulation.

For example, if there are a large number of guests, the maximum circulation mode is turned on, and in the absence of people in the house, ventilation can operate at a minimum intensity.

Inside the ventilation unit there is a heat exchanger - a recuperator. In ventilation units installed in private houses, a cross-shaped heat exchanger is most often used. circuit diagram the operation of such a recuperator is given in the previous article (see the link at the beginning of the article).

Two filters in the ventilation unit - one is installed at the inlet to the fresh air unit from the street, the other is installed at the inlet of the exhaust air that enters the unit from the house. The fresh air inlet filter traps fungus spores, plant pollen, dust, insects, etc. It purifies the air supplied to the house and, in addition, prevents the heat exchanger ducts from clogging.

The filter on the exhaust air side only serves to protect the heat exchanger ducts from house dust. In different designs of blocks, filters can be replaceable or their periodic cleaning is provided.

Heat exchanger frost protection system- a mandatory element of the ventilation unit.

In winter, the warm and humid air leaving the house in the heat exchanger is strongly cooled and water condenses from it there, as in an air conditioner. On frosty days, this water can freeze, the ice will clog and even destroy the heat exchanger channels.

To prevent this from happening, in forced ventilation units There are several ways to protect the heat exchanger from freezing:

When fresh air with low temperature enters the ventilation unit the mode of intermittent supply of this air is switched on. The frequency and duration of interruptions in the air supply is chosen so that the water in the heat exchanger does not freeze. The method is simple, but interruptions in the air supply reduce the efficiency of ventilation of the premises.
The ventilation unit is equipped with a bypass - a bypass duct through which fresh cold air can pass in addition to the heat exchanger. During periods of low temperatures, the flow of fresh air is divided by: part of the air is passed through the heat exchanger, and the other part - through the bypass. The amount of air passing through the heat exchanger is regulated in such a way that the temperature of the heat exchanger allows the condensate to remain in a liquid state.
On frosty days, coming into the ventilation unit cold air is slightly warmed up with an electric heater so as to only prevent freezing of the water in the heat exchanger. Too much fresh air heating will reduce the efficiency of heat transfer in the heat exchanger.

The coordinated work of all elements of forced supply and exhaust ventilation in a private house is ensured by control and automatic control unit.

The ventilation system control unit allows the owner to regulate the amount and temperature of air circulating in the premises, to control the health of individual elements of the system.

More complex control units make it possible to program the ventilation operation in a daily and weekly cycle, automatically adjust the ventilation operation depending on the air temperature outside and inside the house, humidity and carbon dioxide content in the premises.

Built into more expensive ventilation units additional devices air preparation.

In winter, when the heating is turned on, the air in the house often becomes too dry.Household air humidifiers allow to provide comfortable humidity of air in premises.

The temperature of fresh air after the heat exchanger rises slightly, but remains negative on frosty winter days. The supply of such cold air to residential premises will cause discomfort to people, especially those who are near the supply ventilation anemostat. To eliminate this shortcoming the ventilation unit is often equipped with an electric supply air heater - a heater. The heater is switched on only at very low outside temperatures.

To heat the supply air, heaters connected to the heating system of the house are also used. Typically, such a heater is installed as a separate device, outside the ventilation unit.

Where to install the forced ventilation unit

The ventilation unit is most advantageously installed on non-residential attic. In this case, the length of the air ducts from the premises of the house will be minimal.

If this is not possible, then the block is installed in any other place. Usually this is a boiler room, utility room, garage or basement.

The requirements for the location of the ventilation unit are as follows:

Free access to the unit to replace filters, repair and monitor the condition of the unit.
The absence of additional requirements at the installation site to reduce the noise level from the operation of the unit.
The minimum length of the main air ducts of the ventilation system. It should also be assessed whether it will be convenient to spread the air ducts along the building structures of the house.

How to choose the right ventilation unit

The selection of a forced ventilation unit is carried out according to the following main parameters:

Performance, m 3 * hour- the amount of air supplied to the house and removed from the premises per unit of time.
Head, - the pressure necessary to overcome the aerodynamic resistance created by all elements of the ventilation system.
efficiency (coefficient useful action) recuperator - an indicator of the efficiency of heat transfer to fresh air supplied to the house, from air removed from the premises.

The minimum amount of air that the ventilation unit must circulate is determined by sanitary standards. The standard values of air exchange for the premises of a private house are given in the previous article. The performance of the ventilation unit should be more than the amount normative values for all rooms of the house.

In practice, for simplicity of calculations and the creation of a certain margin of productivity, another indicator is used - the air exchange rate. This is a value showing how many times during an hour the air in the room should change.

According to Russian sanitary standards the air exchange rate in a private house should be at least 0.35 times/hour.

For example, the total volume of all ventilated rooms in a house is 450 m 3. Then the minimum required capacity of the ventilation unit is 450 m 3 x 0.35 1 hour = 157,5 m 3 / hour.

In addition, it is necessary to check the fulfillment of one more condition - the air exchange in the house should not be less than 30 m 3 / hour per person living in the house. If this condition is not met, then the air exchange rate is taken to be greater than 0.35.

It is necessary to provide for a certain capacity margin of the ventilation unit for supplying additional air to the heating boiler, fireplace, kitchen hood or in case of receiving guests. Therefore, in practice, the performance of the ventilation unit is determined by taking the air exchange rate in a private house in the range of 0.5 - 0.8 1 hour.

It should be remembered that the ventilation unit, like any pump, has a curvilinear dependence of performance on pressure. The greater the pressure (aerodynamic resistance of the ventilation system), the lower the performance of the ventilation unit. This means that the shorter the air ducts and the larger their cross section, the lower the requirements for the parameters of the ventilation unit - the cheaper the unit, and the less electricity consumption for ventilation.

Calculating the aerodynamic resistance of a ventilation system and determining the required pressure is a rather difficult task. It is better to entrust its decision to specialists.

The correct choice of parameters of the ventilation unit can only be made on the basis of calculations. Often contractors don't bother with this, and offer to install a deliberately more powerful, and therefore more noisy and expensive ventilation unit.

The size of the reduction in heating costs directly depends on the efficiency of the heat exchanger.

The efficiency of cross-shaped heat exchangers does not exceed 60%. In some models of ventilation units, two such heat exchangers are installed, placing them in series one after the other. The efficiency of the system increases by another 20%.

The most expensive ventilation units can contain even more efficient solutions - rotary heat exchangers and even heat pumps(heat pipes). The efficiency of such devices reaches 90%. In Russian conditions, with relatively low prices for fuel, it will not be possible to recoup the costs of installing such blocks.

When choosing a ventilation unit, you should also pay attention to other important parameters for the developer:

Noise level generated by the ventilation unit. If the unit is placed on a wall or ceiling adjacent to the bedroom, you should choose a unit with a minimum noise level or you will have to spend money on additional soundproofing.
The maximum electrical power consumed by the electric heaters of the ventilation unit may exceed the capacity of the electrical network. Think about whether it is more profitable to heat the air with a heat exchanger connected to the heating system.
Estimate the cost of filter replacement, replacement frequency, and continued availability.
If fresh air is taken through a ground heat exchanger, then a ventilation unit equipped with a bypass is selected.

Air intake and deflector of the forced ventilation system

The air intake grille for fresh air ventilation is usually located in the outer wall of the house or on the roof.
The location of the air intake is selected based on the following:

Distance between the air inlet and the deflector through which air is ejected exhaust ventilation, must be at least 10 m. The same distance should be maintained from the chimney, sewer riser and other sources of odors and air pollution.
The air intake is placed at a height of at least 1.5 m from the earth's surface and 0.5 m above the snow cover.
The air intake opening must be covered with a mesh to protect against the penetration of birds, insects, leaves, etc. into the air duct.

Increasingly popular is the air intake device through

Ventilation ducts in a private house

In the forced ventilation system of a private house, round ducts are most often used. standard diameters- 100, 125, 150, 200 and 250 mm. Duct pipes can be made of steel, aluminum or plastic.

How to determine the cross section of the duct

In order for the movement of air in the ducts to be silent, the flow velocity in them must be approximately V=2 — 4 m/s. It is recommended to select a lower value for branch ducts located within the living space, and a higher value for main sections located away from the bedrooms.

Focusing on standard values air exchange, determine the required performance for each point of inflow and exhaust air, Q m 3 / hour.

Sectional area of the duct, A m 2 = Q m 3 / hour / 3600 * V m/s(we take into account that 1 hour = 3600 sec)

Knowing the required cross-sectional area of the duct A, m 2 you can easily calculate its diameter d, m(according to the formula A = π d 2 / 4), whence: d = 2√A /π.
It is recommended to choose an air duct of a standard size with a diameter larger than the calculated one.

Rectangular air ducts take up less space, but have greater aerodynamic resistance than round ones of the same area.

The ventilation unit is connected to rigid pipes of air ducts using flexible elastic pipes with a length of at least 1 m. This decision prevents the transmission sound vibrations from the ventilation unit through pipes to the premises.

Ventilation ducts must be covered with a layer of thermal insulation. The thermal insulation of air ducts prevents the condensation of water vapor on their walls, and also prevents the transmission of sounds through the pipe.

It should be taken into account that not only air moves through the air ducts in the house, but also sound, as well as rodents.

Sound conductors are the walls of air ducts, as well as the air inside them. To reduce the level of transmitted noise, it is recommended to use air ducts made of elastic materials, to paste over the pipe walls with sound-absorbing material.

Sounds transmitted through the air are strongly attenuated with an increase in the length of the duct and a decrease in its cross section. Therefore, when designing the layout of air ducts and the placement of supply and exhaust openings, it is necessary to maximize the length of the air ducts connecting these openings in adjacent rooms.

To protect the ventilation unit and the premises of the house from rodents, metal grilles are installed on all inlet and outlet openings of the air ducts.

The diameter of the air ducts is chosen in accordance with the calculation of the aerodynamic resistance of the ventilation system.

Rectangular ducts are rarely used. Such air ducts are more compactly placed in building construction at home, but they are less technologically advanced in manufacturing, more difficult to install.

Ventilation ducts have a fairly large diameter. Therefore, even at the design stage of a new house, it is necessary to provide places in the building structures for hidden laying of air ducts in the living quarters of the house.

To accommodate ventilation ducts, niches are provided in the walls, channels in the ceilings. Air ducts are hidden behind suspended ceilings, in the frame shell of walls and partitions.

indoors supply air ducts end with anemostats, which serve for uniform air dispersion, and also allow you to adjust the amount of air supplied.

Air from the premises enters the exhaust ducts through conventional grilles.

Ventilation in your city

Ventilation

Why should the ventilation in your house be worse than in your car?!

Design a modern centralized ventilation system with heat recovery for your home.

When building a house, be sure to lay the air ducts and electrical wiring provided for by the project to the central ventilation unit. After the construction is completed, it will be almost impossible to do this.

If the construction budget does not allow you to purchase a ventilation unit with recuperation right away, leave the purchase for later. Install a cheaper supply and exhaust ventilation unit without a heat exchanger.

Recuperation units quickly become cheaper over time, and energy becomes more expensive. Soon, the moment will inevitably come when the price of the unit, the amount of savings in heating costs, the desire for comfort and your income will allow you to purchase a recovery unit and install it on an already prepared site.

Modern construction projects often already include apartment ventilation systems. It is necessary, firstly, to minimize heat loss and achieve the required energy efficiency indicators, and secondly, to ensure high comfort, which is also important characteristic modern home.

Modern apartment ventilation systems work extremely efficiently: the heat exchanger recovers up to 98 percent of the heat contained in the exhaust air and uses it to heat the incoming fresh air. Thus, significant money savings are achieved due to the reduction in the need for energy consumption for heating. In addition, CO2 emissions are reduced, which also reduces the environmental impact. The features of central ventilation are described in the Benefits of Central Home Ventilation section.

Central ventilation at home is more common in new buildings

A central ventilation system is quite often used in new buildings. Its installation is carried out already during the construction phase of the building frame. The air distribution system is installed in the floor structure in an insulating layer. Another possibility is laying in concrete. For this ventilation pipes integrated directly into the concrete ceiling. After the construction is completed, the pipes are hidden and cannot be seen. Therefore, the central ventilation system in a new building should always be planned in advance. Can be used in older buildings central system ventilation, but the installation is somewhat more complicated. Requires intervention in building structures. In addition, you should consider how best to mask the air ducts.

Regardless of the application, homeowners should always trust the design and installation of a residential ventilation system to a specialized company. Trained technicians can accurately calculate all parameters of a ventilation system so that it works as efficiently as possible. What homeowners should consider when choosing right system ventilation, can be found in the "Purchase of central ventilation" section.

Central ventilation system at home

The central ventilation system in the building consists of ventilation unit and air distribution systems. The air distribution system is hidden in the floor or built into the wall. Only the air outlets are visible. The air exchange is controlled independently by a central ventilation unit. This circumstance is described in detail in the section "How the ventilation of the central living room works."