Basement ventilation: general technology of arrangement + methods of effective air exchange

Type of ventilation

First of all, it is worth understanding two types of air exchange. It can be natural or forced. Each option has certain advantages and disadvantages, so let's look at them in more detail.

Natural air exchange

Natural ventilation is called ventilation, which does not require the installation of any equipment designed to stimulate the movement of air.Simply put, air masses lead a completely independent life. To remove the exhaust air, ventilation shafts are provided - in other words, channels cut into the ceiling and wall that go to the roof.

The air that has been in the house becomes warm. As everyone knows from school physics lessons, in this case it starts to rise up. This is what the ventilation ducts are designed for, the entrance to which is located in the upper part of the room. Air masses reach them naturally, and then follow the shaft up, leaving the pipe to the street.

With this, everything is clear. But as you know, the amount of air that has left the house must somehow be replenished. And here lies the problem. It has already been described in detail above that modern walls and double-glazed windows make a dwelling a real fortress, into which the enemy, perhaps, will penetrate, but fresh air definitely won’t.

The problem can be solved in two ways:

• ventilation. Everyone seems to know how this is done - if it becomes stuffy in the house, you need to open the window. In fact, when stuffiness sets in, your brain has already begun to get tired and experience oxygen starvation. This should not be allowed, since often repeated such situations can seriously harm health. For example, it is fraught with migraines - rather unpleasant conditions that are difficult to get rid of. So, in order not to bring yourself to oxygen starvation, you need to do airing not on the fact of the onset of stuffiness, but with a certain frequency - every three hours. The duration of the procedure is 15 minutes. The problem is that not every family has a person who will agree to stay at home all day to periodically open the window.As a rule, most people work, so in the evenings they have to return to their dwelling with stale air;
• use of an inlet valve. This simple equipment is an excellent alternative to ventilation. The supply valve is installed either in the window or in the wall. It consists, in fact, of an air duct, through which air masses circulate. The equipment is designed in such a way that its installation does not affect the occurrence of drafts or temperature changes in the home. Thus, there is no need to constantly open the window - freshness and oxygen flow continuously through the supply valve.

But even the use of a supply valve is not able to solve the main problem of natural ventilation. This is a low air exchange rate. The fact is that, regardless of the method of fresh air intake, it depends on some external factors. First of all, on the air temperature outside and inside the room.

To ensure at least a relatively normal air exchange rate, it is necessary that it be cold outside and hot in the house. The smaller the temperature difference, the slower the air exchange. But what then happens in the summer, when it is equally hot outside and indoors? Never mind. There is simply no air exchange, or it is, but at such a level that there is no sense.

In principle, natural ventilation can be more or less suitable for small houses - there is a small amount of air, the change of which does not take much time. But since today we are talking about two-story buildings, we immediately dismiss this option for the reasons described above.

Forced air exchange

But this method is the one that is suitable for consideration as an application in a private house of any number of storeys. In this case, the air circulation is affected by the use of special equipment, which is installed either in the shaft, or on the roof, or in one of the non-residential premises - for example, on the attic floor. There are also stand-alone devices, which will be discussed below.

Schematic diagrams of natural ventilation

Many years of practice in the construction of apartment buildings has led to the selection of several of the most effective schemes for creating a ventilation system. The choice of one or another scheme depends on many factors: the shape of the building, the number of floors, street air pollution in the area, the noise level.

Schemes of a traditional exhaust system

The system of exhaust ventilation with natural induction is recognized as traditional, that is, when the air in the premises is exchanged due to the difference in temperature and pressure.

This means that the exhaust air is discharged through the ventilation shafts and ducts to the outside (to the roof), and fresh air enters through windows, doors or special supply valves.

One of the options for installing ventilation shafts in a multi-storey building

The option of laying separate shafts for each apartment is not currently being considered, since it was expedient in the era of low-rise construction.

It is clear that for skyscrapers from 9 floors and above, it is not physically possible to equip a plurality of parallel channels.

Therefore, two recognized rational schemes are used in construction:

• All shafts are brought to the attic and there they are united by a horizontal channel.Polluted air is removed from the channel through a single outlet, arranged in the most convenient place.
• Separate apartments are connected to a common riser (shaft) by parallel satellite channels, so the exhaust air is discharged above the roof through vertical channels.

The fundamental difference lies in two points: the presence / absence of a horizontal collector in the attic and the presence / absence of common shafts in the risers.

Diagram of a ventilation device with satellite channels. An important nuance: for the upper floors, the idea of ​​​​a separate direct exhaust of used air has been implemented.

Local drainage from the upper floors is due to the fact that in order to create traction above the apartment there must be a horizontal channel of at least 2 m in height.

Separately removed channels, as well as a common shaft, must be insulated with high quality, otherwise condensation will form in the attic, as a result of which premature destruction of materials occurs, mold appears.

Installation of a horizontal attic box is made taking into account special requirements. For example, its diameter must be sufficient so that no reverse draft is created and air does not return to the channels. This is fraught with the ingress of the spent environment into the apartments of the upper floors.

Calculation of the diameter of the box should be carried out by experienced engineers. In order for the air to move in a given direction and not come back, cuts are installed inside the channel

Sometimes it is not possible to mount a bulky horizontal channel. Then they get by with a narrow section of the pipe, but for the upper floors they use the same local system - separate sleeves introduced into the attic.

Natural ventilation, which is equipped with almost all houses of old buildings, has a significant plus - it does not need power supply.

However, its effectiveness depends on the temperature difference between the building and the room, and shafts and channels require constant cleaning, which is extremely rare in practice.

Features of the location of channels in a 9-storey building

In typical houses, the process of air change is carried out in a natural mode. The influx of fresh air masses occurs in apartments, the discharge of the exhausted environment is carried out through ventilation shafts equipped with satellite channels.

Most often, the channels are laid from the exhaust openings in the apartments according to the “through 2 floors” scheme, but they can also be floor-by-floor.

Scheme of the ventilation device, typical for a standard multi-storey building. The common exhaust shaft goes straight to the roof, satellite channels are laid in parallel and connected in turn

According to the norms, the removal from 8-9 floors is carried out not through a common shaft, but separately. When drawing up such a scheme, averaged atmospheric conditions are taken into account, that is, the air temperature on the street is +5 ° C and the absence of wind.

This scheme is recognized as ineffective, since when natural conditions change, the functionality of natural ventilation decreases. For example, in extreme heat, it is useless. It is also possible that the ventilation ducts are clogged, which completely blocks the movement of air.

In the absence of a normal hood, emergency cleaning will be required. Although it is usually carried out every 5-6 years.

Calculations and installation of ventilation

Before proceeding directly to the installation of the system, it is necessary to carry out preliminary calculations.A self-made ventilation scheme will allow you to understand the basic principle of operation and eliminate possible errors even at the planning stage.

First of all, determine the type of ventilation, based on the purpose and area of ​​\u200b\u200bthe room.

Let's take a closer look at the basic calculations:

1. We calculate and mark on the diagram the required number of ventilation ducts, depending on the power of the built-in equipment.
2. We calculate the cross-sectional diameter of the exhaust pipe based on 26 square centimeters of pipe diameter per square meter of serviced area using the formula √ (26 × S) / 3.14) × 2, where S is the serviced area of ​​​​the base. For houses located in the lowlands, the estimated size is increased by 15-20 percent.
3. To determine the optimal length of the ventilation pipe, the heights of the house from ground level, the recessed part of the basement floor and the heating system pipe above roof level are summed up.

The installation of the forced ventilation system begins with the punching of the air line. For installation of the supply part, a channel is drilled into wall at the level of the lower window edges.

A pipe is inserted into the opening, closed from the side of the street with a decorative lattice to protect it from precipitation, insects, and rodents. The gaps are filled with mounting foam.

Ventilation pipes are installed at an angle of 10-15 degrees outward so that the condensate formed during the cold period flows to the street, and does not accumulate inside. From the side of the premises, a forced ventilation device is mounted.

The main unit of such a device includes: a fan, a filtration complex, a check valve. A valve or plug is needed to prevent cold outside air from entering when the equipment is turned off.

The exhaust duct is installed on the opposite side of the supply fan, at a level of one and a half meters from the floor. To be able to regulate air flow, the ventilation system is equipped with a set of dampers.

Be sure to insulate the exhaust pipe. The insulation must be moisture resistant, have a waterproofing layer. A deflector is fixed at the outer end of the duct.

Made of aluminum, plastic or ceramics, the device will increase traction, protect the hood from precipitation, debris, will not allow ice to form in winter.

Natural type air exchange: principle of operation

Using the example of panel houses built in the last century, you can see how natural ventilation works in an apartment building. It belongs to the budget option, unlike elite buildings, where modern standards apply, new technologies are used, and energy-saving materials are used.

A natural type of ventilation can also be found in a brick house of an old housing stock, where air enters through the slots of the porches of wooden windows and doors, and the exhaust is carried out by a draft inside a vertical channel, with an exit above the roof or into the attic. Blocking the supply duct is fraught with a cessation of air exchange throughout the apartment. The insertion of special valves into window structures, overflow gratings in the door solves the problem of uninterrupted operation of natural ventilation.

The ventilation device in an apartment building with separate exhaust ducts for the kitchen, bath and toilet is one of the ventilation schemes. Here, from the listed rooms of each floor, a separate shaft goes to the roof. With its tightness, odors do not flow from neighboring apartments.

Another air exchange scheme includes vertical channels of all apartments, united by outlet ends in one longitudinal manifold. It is located in the attic, and already through the collector the air enters in an organized way into the street. To eliminate pressure losses in the air ducts and increase the draft, the joints are sealed, and pipes are put on the outlet ends of the channels: it is enough to add only 1 m of a pipe segment and orient it at an angle to the common exhaust shaft.

The least efficient, but also viable method is to collect the exhaust air from each apartment into a vertically installed air duct. The efficiency of the system is low, as odors flow from the premises of one apartment to another.

The most optimal and efficient ventilation systems (forced) are currently used in modern houses, where air is forced in and out mechanically. The peculiarity of air exchange here is the use of energy-saving installations - recuperators. As a rule, the fresh air blowing device is located in the basement or technical floor. Additionally, the air is cleaned through a filter system, heated or, conversely, cooled and only then distributed to all apartments. At the upper level (roof), a ventilation unit of identical performance is installed, which completely removes all air pollution.

Assessing different types of ventilation, it should be noted that natural air exchange is not very efficient, but it also clogs the ventilation shaft least of all. If there is no construction debris in the channel, then it is enough to clean it once every few years.

Deficiencies in ventilation

The disadvantage of the scheme with a horizontal box is the presence of reverse thrust. It appears if the cover in the horizontal box is set too low. Residents of the upper floor suffer from reverse thrust. There are two ways to fix the deficiency:

1. Increasing the diameter of the box by 2.5 times, installation inside the "cuts".
2. Arrangement of ventilation ducts of the upper floors separately from the general system, lead them into the shaft above the box.

All work must be carried out by professionals. Separate channels of the upper floors require insulation.

The second scheme of the ventilation project has disadvantages:

• weak draft on the upper floor;
• ventilation does not work when the doors are open in the attic.

Ventilation in the foundation of the house - how to circulate air and get rid of condensate

To ensure ventilation of the underground space, various methods are used:

• perform special vents at the base of the building. Excess moisture is removed by natural air circulation. With the correct selection of the section and the location of the channels, a draft occurs that does not allow condensation to form;
• organize the extraction of air masses from the space located under the floor with the help of a ventilation pipe. It is displayed at the roof level, and air access is carried out through the highway passing inside the room. In this embodiment, the basement ventilation ducts are not performed.

Many “self-builders”, having equipped their own home with a good ventilation system, completely forget about the ventilation of the foundation, which is the basis of any structure.

The location of the building also affects the intensity of air exchange:

• for air circulation in buildings located on flat terrain, it is enough to make a pair of channels with a diameter of 150 mm. They must be placed on opposite sides of the tape base;
• the base of a building located in a lowland, where the air flow rate is negligible, should be ventilated more intensively. For this, additional channels are provided along the contour of the base.

There are proven solutions to reduce the formation of condensate. They provide:

• thermal insulation of the foundation, which is additionally protected by a waterproofing coating;
• insulation of the basement floor with the help of modern heat-insulating materials.

Do-it-yourself basement ventilation

Modern cottages are less and less reminiscent of old wooden houses, which had low foundations and low ceilings. Today, these are modern spacious buildings with a basement floor that houses a boiler room, a laundry room and even a sauna with a swimming pool. For such rooms, plinth ventilation must be provided without fail. It will allow them to maintain normal temperature and humidity in them, and will not allow mold to appear on walls and other surfaces.

Basement ventilation

No one doubts the need for regular ventilation of basement rooms. But how to do it right? Experts advise equipping basement floors not only with ventilation ducts, but also additionally equipping, at least on one side, a window the size of a window in the upper part of the room.

Since basement ventilation allows for good microclimatic conditions in the basement, its arrangement should be thought out at the design stage. Only a properly selected and equipped system determines how effectively the basement can be used for household needs.

At the design stage

If a basement is provided in the cottage, then special openings will have to be located in its walls, playing the role of a natural air exchange channel. They are also called vents. At the design stage, be sure to take into account:

• type of soil on which the structure will be located
• foundation depth
• wind rose
• terrain

Experts advise: basement ventilation should have one hole every 2-3 meters of the wall. When placing a house in a lowland, their number should be increased.

We equip air exchange

Very often, when placing utility rooms in the basement, some products are not enough. In this case, it is recommended to additionally equip the supply and exhaust system, which will help maintain the level of humidity. The purpose of this system is to supply fresh air to the basement and remove exhaust air from it.

Such ventilation is based on the temperature difference between the room and the street. But in order to exclude drafts in the basement, it is necessary that not only the basement ventilation is correctly calculated, but also its placement and installation meet all the requirements.

It consists of two pipes - supply and exhaust. It is desirable that they be located at different ends of the basement, and also differ in height. Since cold air is heavier than warm air, it sinks down to replace the air leaving the room.This means that the exhaust pipe is installed much higher than the supply pipe. Usually it is located near the ceiling and brought to the roof through the ventilation duct.

The supply channel is installed on the opposite side of the basement and at a height of no more than 0.5 m above the floor level. It must be borne in mind that the higher the exhaust pipe and the greater the temperature difference between inside and outside, the faster the air exchange will be. The ventilation supply channel must also be brought to the roof and raised above the ridge.

To regulate this type of air exchange, the channels are equipped with special slide gates.

If, with a natural system, the ventilation of the basement is insufficient, then a combined version can be equipped. To do this, a fan can be mounted in the cavity of the exhaust pipe, which will forcibly expel the exhaust air.

No. 5. Forced forced ventilation in the apartment

The task of forced ventilation is to provide the apartment with fresh air, while the exhaust air exits through the existing ventilation ducts, i.e. through openings in the kitchen and bathroom. There are a lot of options for inflow, and the choice depends on the requirements for comfort and budget.

The supply ventilation system can be organized using the following devices:

• valves that are installed in a wall or on a window. This is the simplest option, which is an analogue of those slots included in the project, only valves are already a prettier and slightly more functional way of ventilation. The air flow through the valve is manually regulated, filtration is either not provided or is minimal and allows you to screen out insects and large debris.As a rule, air heating is not provided for in such systems (therefore, it is better to place them in the area of ​​\u200b\u200ba heating radiator so that the air warms up at least a little in winter), and a sound-reflecting visor saves from noise in window valves. These valves work best in winter. To equip the wall valve, you will have to make a through hole in the wall;

• mechanical ventilators are already more modern devices, they can have different power and functionality, and the process of supplying fresh air becomes controllable. Even if the conditions are unfavorable for the natural intake of air from the street, it can be forcibly overtaken. Filtration is represented by a coarse dust filter or a carbon filter, which is not bad. In the most advanced devices, even air heating is present. As a rule, such ventilators are equipped with a control panel or remote control. With all the advantages of such systems, do not forget that they will take more time to install, and operation will require the use of electricity;

• the breather is an even more advanced installation that allows not only to supply the room with fresh air, but also to purify this same air using HEPA filters, such as those used in modern vacuum cleaners. Such filters trap not only dust particles, but also allergens, microbes, pollen, mold spores, so the breathers are ideal for apartments where children, asthmatics or allergy sufferers live. The filtration system includes other types of filters. The device can heat the air, and the fan, as a rule, operates in several modes, allowing you to provide the required amount of air.Breezers are equipped with a display and a control panel, the unit takes up a little more space than the indoor unit of the air conditioner. The only disadvantage of such devices is the price;

• the supply system with mechanical stimulation is the most complex and expensive. It consists of a system of air ducts that hide behind false ceilings and massive ventilation equipment that is placed on the balcony. It consists of fans, filters, humidifiers, heaters, coolers and even fragrances. Air enters the rooms through ducts with diffusers. The system has its advantages, but it is too expensive and difficult to install.

Do-it-yourself hood in the cellar

The ventilation scheme depends on the parameters of the house, the purpose of the basement and the location with climatic features. To equip a conventional system, you will need two pipes (one for supply, the second for exhaust), which will be responsible for air circulation in the storage.

Do-it-yourself ventilation system in the cellar can be made natural or forced. In forced, the main role is played by fans that will circulate air in the room

Also, when choosing special equipment for ventilation, you need to pay attention to the stability of the equipment to work in conditions with high humidity.

You will find more information about self-arrangement of ventilation in the basement in the video.

Materials for manufacturing

The existing ventilation schemes in the cellar include the use of various types of pipes in them. Among the large assortment, the most common are asbestos cement and low-pressure polyethylene.

Products based on asbestos cement look like slate, but according to their characteristics they have the following qualities: reliability, high level of strength, adhesion resistance, durability. In construction stores, they can be purchased in long lengths, which will favorably affect the integrity of the structure. Polyethylene pipes most often have to be welded together, which requires special tools and work skills.

Metal pipes are used extremely rarely for the installation of a ventilation system, since they are exposed to corrosion and quickly rot in the ground. In measures to prevent such impacts, it can be treated with anti-corrosion enamels or waterproofing materials can be used to protect against moisture.

During the use of any material, the openings for the exhaust and supply pipes must be reliably protected from moisture and debris. For such purposes, it is necessary to install a grate and a special cap on it, which can be made from any material.

Fan types

For proper air circulation in the storage, several types of fans can be used, which, according to the principle of operation and location, are divided into axial and duct (Figure 4).

Figure 4. Types of fans for basements

The duct fan has an average power level and can be mounted anywhere in the ventilation pipe. The power consumption of this type of fans is negligible, which is suitable for saving money. One of the most efficient duct fans are amplitude-type devices.

Axial fans are installed in close proximity to the exhaust or supply openings. According to their principle of operation, they can produce a stronger air circulation, but at the same time they are demanding in electricity. Together with the fan, a special valve is mounted on the outlet pipe of the system, which will not let cold air in.

Forced type systems

In modern housing construction, plastic and metal-plastic structures are used to seal window and balcony openings. Double-glazed windows made of polymers and aluminum are stronger than wood, but often completely block the natural channels of fresh air.

The doors are also tightly attached to the floor, making the rooms absolutely airtight. Air does not enter, and in the absence of an effective supply system, the exhaust system becomes useless.

To solve the problem of fresh air access to all apartments, centralized supply ventilation equipment is installed in elite residential buildings.

Unlike natural ventilation, incentive ventilation is volatile. In addition, it consists of a set of complex devices that are controlled from one remote control. Shuv is installed next to the supply equipment, in the basement, and only qualified service personnel have access to it.

It can be said that all three types of ventilation are present in residential high-rise buildings, with natural being the most common, and the installation of a forced or combined system is still limited.

Pros and cons of different types of ventilation

With non-stop air circulation, the temperature and humidity regime will be stable, however, in the cold season, the room may freeze.

1. The channel is necessary to remove moisture, odor and toxic compounds.

2. The supply pipe provides fresh air to the interior of the cellar.

3. The single-pipe system is the simplest method, which has its pros and cons:

• the positive side is the low cost of the hood and the relative ease of installation;
• the disadvantage is that full-fledged air exchange is problematic due to weak inflow.

If the cellar is small, then it is recommended to install this option. The air duct must be divided into separate ventilation openings.

4. Installation of a two-pipe type is preferable because of the ability to ensure greater safety of provisions and things that are underground, but it requires large financial costs.

The correct design approximately 2 times per hour completely changes the air in the room. The circuit diagram with natural circulation is laid down in the project at the initial stage of its creation.

In what cases can you get by with one pipe and determine the diameter

In a separate cellar with a small area, as well as in a garage or barn, a single-pipe system is installed. Its top should go out at a distance of at least 80-100 mm from the roof ridge.

• In a structure with a perimeter of 2x3 or 3x3 m, it is necessary to erect a structure with a cross section of at least 150x150 mm, with a wind catcher at the end.
• The hood is necessarily divided in half by a vertically located partition that runs along the entire length.
• In one compartment, air enters the room, in the second it leaves it outside, so for each part a separate damper is made, which closes.
• Before completing the installation, it is necessary to check the circulation. To do this, you can smoke the underground and monitor the pace of cleaning.

In order for the system to function correctly, it is necessary to accurately calculate the diameter of the ventilation ducts.

• The underground area should be proportional to the cross section of the pipe and be 1m2 / 26 cm2.
• A pipe diameter of 1 cm is equal to 13 cm2 of section, hence: (Sroom x 26 cm2) ÷ 13. If S of the basement is 9 m2, then it will turn out (9x26) ÷ 13 \u003d 18, which means that the size of the cross section must be at least 18 cm.
• ventilation pipes are taken 1-2 cm more than the value obtained. For S = 9 m2, it is necessary to take a material with a cross section of 19-20 cm.

From the side of the street, the channel is located in places accessible to blowing by strong winds, otherwise it will be inactive.

Which channel to close for the winter, the nuances of the hood with two pipes

The use of a two-pipe design to form a full-fledged supply and exhaust system requires the most accurate calculation, therefore, it is desirable to first create a circuit.

• For uniform air exchange, channels with an equal cross section are installed. If it is necessary to drain the cellar or get rid of a musty smell, then the outlet should have a large diameter.
• The fewer twists and turns, the better the ventilation will be.
• Optimum temperature conditions and circulation are achieved due to the maximum removal of the hoods from each other. It is preferable to place them at different ends of the room.

View	Installation	Nuances
exhaust	The lower end is 150 cm from the floor, as close to the ceiling as possible. The output channel to enhance traction is closed with a mesh or a deflector is attached to it.	1. The ventilation openings of the pipes must have a height difference of at least 100 cm. 2. The supply channel of the underground on the street is below the exhaust. 3. Air masses form condensate: when winter comes, it cools down and turns into frost. The street end requires mandatory insulation. 4. To remove condensate, a drain cock is mounted in the lower part of the exhaust pipe.
Supply	The hood should be at a height of about 30-50 cm from the floor. The outer end rises above the roof by a maximum of 25 cm. If the channel is arranged in the ceiling of the basement, then a grill is attached to it from the outside, which protects against the penetration of rodents.

In order to regulate the intensity of air movement, it is necessary to open and close dampers installed on the ends of the hoods located inside the room.

Conclusions and useful video on the topic

The following video will acquaint you with the steps for installing air ducts:

The principle of operation of the gravity ventilation system is presented in the video:

Ventilation hood guide:

So, in a cottage, regardless of what building material and in what area it is built, a full-fledged air exchange is necessary. A reasonable choice would be supply and exhaust ventilation, the development of which must be included in the project.

Knowing the principles of organization, the gravity system can be easily handled without the involvement of builders. It is more correct to entrust the design and installation of mechanical ventilation to heat engineers.

Do you want to share your own experience in the construction of a ventilation system? Do you have information on the topic of the article that may be useful to site visitors? Please write comments, ask questions and post photos in the block form below.