How to make ventilation in a garage, features and subtleties of popular ventilation systems

If your garage does not have a well-functioning ventilation system, you will have to forget about real comfort: the constant presence of harmful impurities in the air, coupled with the unhealthy smell of dampness, will reduce the pleasure of even the most spectacular and modern decoration to zero. That's why normalizing air flow is one of your main responsibilities. We’ll talk about how to do ventilation in a garage with high quality and in accordance with all the rules with your own hands. For clarity, there is a detailed process flow chart, diagrams and numerous photos that will help keep everything under control.

Ventilation schemes

There are three ways to establish air circulation in a garage, and there is no fundamental difference whether the garage box is equipped with a basement or not. The diagrams look like this:

Natural ventilation. It works due to the fact that the temperature inside and outside the garage is different. Despite the simplicity of implementation, it requires some (simple) calculations.
Forced (mechanical). It is divided into three types: supply, when outside air is forced in, exhaust, when air is removed from the room, and supply and exhaust. In the latter case, equipment (fans) is used for both air inflow and air outflow. The most effective, but also the most expensive scheme.
Mixed (combined). Combines the two previous schemes: natural ventilation is supplemented by an exhaust duct fan. The combination provides a good result in spacious rooms.

Ventilation grille for air intake Source gazeta-pravo.ru

Air exchange classes in the garage

It should be noted that ventilation of a garage box with and without a basement is practically no different from each other.

Do-it-yourself ventilation in the garage can be made according to the following schemes:

natural. Is the simplest of all. Air exchange in the room is carried out due to the difference in temperature in the room and outside;
mechanical (forced). The system is expensive, but the most effective. Air exchange occurs due to equipment that supplies and removes air;
combined. It works similarly to natural, differing by adding a fan to the circuit to remove air from the room.

Problems solved by the ventilation system

The need for ventilation is specified in SNiP, which specifies air exchange standards and related parameters. Air circulation established according to the rules allows you to solve the following problems:

Removes high humidity from the air. If moisture has nowhere to go, it will begin to settle on the car. Constantly forming condensate will inevitably lead to metal corrosion.
Condensation is harmful not only to the car, but also to the building structure, tools and things stored in the garage box (for example, a bicycle). Reducing humidity extends their service life.
The ventilation system removes not only excess moisture, but also gasoline vapors, as well as chemical compounds derived from a running engine. The less you inhale this bouquet, the safer it is for your health.
Air exchange maintains a comfortable temperature, which creates suitable conditions for long-term storage of food.

Ventilation diagram for a garage with a cellar Source nikastroy.ru

Requirements

SNiP states that fresh air should be supplied inside the garage in an amount of 180 l/hour. In accordance with the requirements specified in document SNiP 21-02*99, any outbuildings (including garages) must be equipped with suitable ventilation communications.

Despite the complexity of the design, ventilation should be in both heated and unheated garages. In accordance with the standards, the incoming volume of clean air must renew the entire internal volume of the room 6-10 times during the day.

SNiP on dimensions and ventilation

SNiP rules provide for ventilation in garages without a basement (as in non-residential premises) with the following features:

Constant air circulation is organized, and its parameters do not depend on the material from which the garage is built, whether it is brick, concrete or metal.
The standards provide for an air exchange of 180 cubic meters per hour per passenger car. Conditions can be ensured using natural, forced or mixed ventilation systems.
Additional (increased multiple) air exchange standards apply for rooms in which vehicle maintenance is carried out (repair, assembly, painting). In this case, the volume of the box is multiplied by the coefficient (multiplicity) of air exchange (standards are indicated for different types of work). For example, the coefficient for service stations is 6-8.
The rules provide for the possibility of heating or not heating the garage space. Winter temperature +5°C is considered the most rational for storing a car. The owner would be more comfortable at +10-15°C, but in such conditions, ice and snow on the car create a humid environment.

Painting or welding work requires increased ventilation Source project-home.ru
To determine the amount of air that needs to be replaced in the garage per hour, perform the following calculations:

The volume of the garage is calculated by multiplying its length, width and height. For example, for a building with dimensions of 6x4x2.5 m, the volume will be 60 cubic meters.
If the owner is engaged in repairs and minor restoration, a coefficient for a service station of 6-8 is used.
Multiplying the unit volume and the multiplicity gives 360-480 cubic meters per hour. This is the volume of air that should change every hour. Such circulation can be organized using only a mechanical ventilation system with the installation of round duct fans.

Stove chimney as an element of the ventilation system

Since in winter many motorists heat their garages with wood and oil stoves, a number of points should be taken into account when organizing air exchange:

A boiler or furnace requires air to burn fuel. The heater takes it directly from the room, so you need to take care of replenishment - ensure an influx from outside.
A properly installed stove chimney is a good exhaust hood that works constantly, even when the flame in the firebox goes out.
From the previous paragraph it follows: the chimney pipe easily replaces the ventilation duct, so there is no point in assembling a separate hood. One condition: after extinguishing the stove and leaving the box, fully open the damper - the draft regulator in order to improve air exchange.

The stove chimney, with the draft regulator open, is capable of removing a sufficient amount of air

Food for thought. Often, owners of garages and private houses are prejudiced against ventilation. Argument: together with the removed air mass, the building loses heat. We answer: the amount of losses directly depends on the inflow - how much air the grille lets in, how much air the hood releases to the street.

Conclusion: adjust the cross-section of the inlet openings with doors and gates. The ideal option is to install a supply wall valve.

Adjustable inlet valve built into the external wall

Features of different types of ventilation

The natural scheme involves the movement of air through some kind of air duct (for example, ventilation is often built in a garage from sewer pipes). Due to the temperature difference, warmer (and lighter) air flow moves from bottom to top, giving way to cooler air mass.

Natural circulation has many advantages to become widespread enough. It is reliable and inexpensive, operates silently, is designed for long-term operation and does not require energy sources.

Calculation of ventilation system sizes Source nataros.ru

See also: Catalog of companies that specialize in engineering systems (heating, water supply, sewerage and others) and related work

From time to time, a shortcoming of the system appears: efficiency decreases noticeably in the summer, when the temperature difference becomes minimal. Performance is determined by the following characteristics:

Temperature difference. The system works best when it is much warmer in the garage than outside. In this case, warm air is actively displaced by cold, denser outside air.
Atmospheric pressure. From the physics course we know that with increasing altitude above sea level, pressure drops. To arrange air circulation in the garage, a very small pressure difference is enough. This can be organized by placing the inlet and outlet openings with a height difference of 3.5-4 m.
By the wind. The wind creates a zone of high (windward) and low (leeward) pressure. This can be used to advantage if you install the inlet along the wind rose (from the side of the prevailing wind).

The mechanical system creates forced air exchange using electromechanical devices. It includes one or more fans, sensors, dampers with manual or automatic control.

A duct fan will ensure effective ventilation of the garage Source serebklych-uk.ru

The system is assembled according to one of three schemes: supply, exhaust or supply and exhaust, and has the following advantages:

Its effectiveness is not affected by weather conditions and time of year.
Allows you to adjust (if there is a controller) air exchange parameters. You can change the performance and temperature to achieve a comfortable environment.
It is possible to organize a warm influx, that is, in fact, alternative heating.
The forced scheme is convenient to use in a garage located in the basement (below ground level).

The disadvantage of the automatic circuit is its complete volatility. It also requires funds for the purchase and installation of equipment. During operation, it needs increased attention, and periodically, qualified maintenance.

Combined ventilation is implemented as natural ventilation, supplemented by a fan. If you use a garage box only for car storage, you can use a household fan for the hood; Ventilation of the garage basement requires additional equipment.

The right microclimate will help preserve the harvest Source nataros.ru

The main advantage of the combined scheme is its efficiency: it mainly operates in natural mode, the fan is connected when the natural outflow cannot cope. Disadvantage: the need to install additional elements.

Ways to improve natural ventilation

Without using mechanical tools to enhance air exchange, you can achieve a stable renewal of the atmosphere in the garage in two ways - by heating the exhaust pipe and installing a deflector on it.

Warming up the exhaust duct

Warmed air is lighter than cold air masses entering through the supply air intake. Striving for the highest point, it exits through the exhaust ventilation duct, being replaced by fresh air from outside - the pressure of the internal (in the garage) and external (on the street) atmospheres should be equal.

When building natural ventilation in a car box, it is enough to follow the recommendations of this diagram

To improve the heating of air in the upper layer of the atmosphere inside a cold garage, you need to paint the exhaust duct black. As a result, the walls of the duct will absorb the maximum amount of solar energy and will heat the air inside the duct, causing it to move upward more intensely.

When planning natural ventilation taking into account the black color, you should not insulate the ventilation duct. However, for the “heating with an incandescent lamp” method, it is extremely necessary to thermally insulate the exhaust duct.

It gets cold in the garage in the fall. This is not a problem for a car, but for supply and exhaust ventilation it is very bad.

If the hot engine for the first hour after entering the box still serves as a source of heat for the air, then after a couple of hours in the unheated garage the temperature will be almost equal to the street temperature. And natural ventilation will stop working.

The wind flow blows over the deflector (diagram a), the air from the exhaust duct is divided into several directions (diagram b). In this case, multiple zones of low (-) and high (+) pressure appear

A regular 40-watt incandescent lamp will allow you to maintain air exchange and prevent icing of the exhaust duct (condensation will accumulate in it).

It is enough to hang its cartridge under the opening of the vertical exhaust duct and leave it on. The heat generated by the lamp is enough to move air at a speed of 0.2-0.4 m/s.

Moreover, the air duct must be wrapped in thermal insulation material and make sure that no moisture enters the insulation. There is little heat from the incandescent lamp; it may not be enough for the full length of the exhaust pipe and the air will quickly cool down.

Note that the use of fluorescent or LED lamps does not improve air exchange - they generate significantly less thermal energy. Only incandescent lamps are suitable.

Installing a ventilation deflector

This device helps to increase the exhaust draft by up to 20% without the use of any mechanical devices - due to the formation of a low pressure zone at the head of the air duct.

Based on Bernoulli's law, deflectors change the movement of air flows due to their design (section).

The parameters of the TsAGI deflector elements are tied to the diameter of the exhaust ventilation duct. The numbers in the diagram indicate: hood head (1); diffuser glass (2); outer casing (3); hood struts (4); cap (5) (+)

The wind is forced around the curved body of the deflector, which leads to the formation of miniature zones of relative vacuum, causing the mass of air in the pipe to move upward.

Structurally, the ventilation deflector (using the example of the TsAGI project) consists of the following elements:

A diffuser (glass) in the shape of a truncated conical pipe. The narrow side fits onto the exhaust pipe. Helps establish air pressure differences and increase traction.
A cap (umbrella) that protects the air duct from the penetration of flying debris and precipitation.
Outer body having a cylindrical shape. Creates low pressure zones by cutting wind flow.

The TsAGI deflector type is widely used to enhance the natural draft of ventilation pipes in Russia. Along with it, disc-shaped, weather vane, H-shaped and rotary deflectors are known.

By the way, domestic natural ventilation hoods are especially often equipped with a Grigorovich deflector.

The efficiency of exhaust deflectors of any design is directly related to atmospheric conditions, namely the presence of wind.

That is, in strong winds this device develops maximum thrust in the natural ventilation system, but in calm conditions it does not work at all.

The defining moment is the proximity of the roof ridge. The closer it is to the pipe, the higher it should be raised (+)

The deflector can not only improve draft, but also prevent “clogging” of the exhaust pipe during strong winds, which low-current natural ventilation cannot overcome.

In addition, the ventilation complex equipped with a deflector device is most protected from draft overturning.

We draw attention to the need to raise the headband of a hood equipped with a deflector above the roof plane by half a meter or more. The location conditions regarding the proximity of the roof ridge, discussed in the diagram above, also apply.

Natural ventilation device

Questions about how to properly install ventilation in a garage often have to do with organizing natural circulation, which is not surprising: there are several subtle points in a seemingly simple scheme.

Before starting work, you need to calculate what diameter pipes you will need. SNiP rules stipulate that a square meter of garage area corresponds to 1.5 cm2 of air duct diameter. For example, for a box with an area of 20 squares (5x4 m), a pipe with an internal diameter of 20x1.5 = 30 cm2 is required. If you want to install not one, but two hoods (and, accordingly, two supply channels), their diameters will be half as large (two 15 cm each).

The system is attractive due to its ease of installation; construction consists of the following stages:

The exhaust hole is made 10-15 cm below the ceiling. The pipe is brought above the roof to a height of half a meter and protected with a mesh and a cap.

The simplest natural ventilation Source nataros.ru

Process flow chart

Let us consider in detail the algorithm for arranging natural ventilation from sewer pipes. As an example, we take a conventional garage with a total area of 20 square meters. meters.

Step 1. Calculations.

For every 10 sq. meters of room area should be at least 15 cm in diameter of the channel. Accordingly, for a garage of 20 square meters you need a channel with a diameter of at least 30 cm. But if you make several exhaust holes, then divide these 30 cm by their number.

Step 2. Draw a diagram of the location of the ventilation holes.

To simplify the process, we offer you ready-made options that may well be suitable.

Step 3. Create an opening into which air will flow.

This is done with a hammer drill - just count at least 10 cm from the floor.

Step 4. Make an exit.

It is best to do it on the opposite wall - with the only difference that 1 cm this time is counted not from the floor covering, but from the ceiling.

Step 5. Install the pipe. It can be metal or plastic and must extend above the roof at least 30-40 cm.

Step 6. Fill any voids between the pipe and the wall with sealant. This will prevent condensation and the spread of dampness.

Step 7. Place the deflector on the pipes.

This is a simple device that will significantly speed up the movement of air back and forth through the pipes. In addition, it prevents precipitation from penetrating the pipes.

Ventilation diagrams with inspection pit and basement

Very often there is a need to arrange ventilation for a garage with a cellar and an inspection pit. Air circulation is necessary both for comfortable work in the pit and for removing moisture from stored products.

As a rule, the power of the ventilation system organized in the garage is sufficient to ventilate the pit. If the pit is covered with boards or shields, there is no need to install a separate structure; The ventilation problem is solved in two ways:

Boards are periodically removed from the pit.
The pipe from the supply channel is extended into the pit. For installation, you can use plastic sewer pipes.

In a garage with a basement, a natural, mechanical or combined ventilation scheme can also be implemented; The first option does the job quite well. However, if you need to ensure ventilation of the vegetable cellar, the work becomes somewhat more complicated. To ventilate a garage with a basement, you need to organize:

Supply air duct. As in the case of the inspection pit, the supply channel is extended down into the cellar. It ends at a distance of 20-50 cm from the basement floor.

Scheme with extended channels Source pinimg.com

Additional exhaust duct. It starts under the ceiling of the cellar and connects to an exhaust duct that discharges air to the street. The exhaust pipe is equipped with a tap for draining condensate.
Pipes indoors are insulated to reduce the formation of condensation (it will inevitably appear due to temperature differences).

Calculation of ventilation air volume and channel cross-section

The vast majority of motorists do not bother with calculations - they studied the diagrams on the Internet, watched a video and installed air ducts from Ø100 mm in-house sewerage pipes. If you want to delve deeper and calculate the parameters of a garage ventilation system, we suggest that you familiarize yourself with the requirements of regulatory documents:

Air exchange inside the boxes is regulated by the regional document MGSN 5.01-01 “Parking areas for passenger cars.” Paragraph 3.17 states: the minimum air flow rate for 1 car is assumed to be 150 m³/h, or a double renewal of the air environment is provided.
Departmental standards VSN 01-89 put forward the following requirement for inspection pits: the exhaust ratio from the ditch must be 10.
Air exchange standards for storing vegetables are prescribed in clause 8. 1. 4 of document NTP-APK 1.10.12.001-02. The volume of inflow and exhaust is 3.5 m³/h for every 100 kg of potatoes and 7.5 m³/h per 100 kg of other vegetables.

Reference. The air exchange rate shows how many times within 1 hour the influx renews the air environment in the volume of the box.

The progress of the calculations is easiest to show using the example of the garage shown above in the drawings. We preliminarily determine the internal volume of the room - 95 m³, ditch (6.6 m³) and cellar (12 m³). Further calculation is performed as follows:

According to MGSN 5.01-01, we multiply the volume of the box by a factor of 2, we obtain an air flow of 95 x 2 = 190 m³/h. The figure meets the minimum requirement for 1 machine 150 m³/h.
The exchange rate in the pit is assumed to be 10, the amount of air is 6.6 x 10 = 66 m³/h.
Suppose 400 kg of potatoes and 200 kg of other vegetables are stored in the basement. We calculate the ventilation air flow: 3.5 x 4 + 7.5 x 2 = 29 m³/h.

Comment. A tenfold exchange in the ditch must be laid when constantly carrying out repair work from below the car (as in a car service center). Under normal conditions, a twofold renewal of the air environment is sufficient: 6.6 x 2 = 13.2 m³/h.

Knowing the costs in each garage compartment, it is easy to find out the cross-section of the supply and exhaust air ducts using the formula:

F – channel cross-section in square meters;
L – inflow volume (flow), m³/h;
ʋ — air flow speed in pipes and grilles; with natural exhaust, it is recommended to take 1 m/s.

For an ordinary garage, where the ditch is used periodically, we include in the calculation the minimum costs of 150 and 13.2 m³/h. We sum up these values and determine the cross-section of the ventilation duct: F = 163.2 / 3600 x 1 = 0.045 m². Using the formula for the area of a circle, we find out the diameter of the air duct - 240 mm. With a slight stretch, the use of two plastic pipes Ø150 mm is allowed.

Example: a grid measuring 230 x 230 occupies 0.053 square meters. m., and its open cross-section is only 0.02 square

The figure 0.045 m² also shows the required flow (live) cross-section of the supply grille, which is approximately 50% smaller than the actual dimensions of the product. This means that we take a cross-sectional area of 0.045 x 2 = 0.09 m² and, by selection, find out the dimensions - 0.3 x 0.3 m or 300 x 300 mm. This grid is too big, it is better to make 2 openings in the wall and install two grids with dimensions of at least 150 x 300 mm.

The size of basement air ducts is calculated in a similar way: F = 29 / 3600 x 1 = 0.008 m². The diameter of the pipe will be 0.1 m or 100 mm. For details on the nuances of installing ventilation in a garage and the passage of pipes through the ceiling, see the video:

Forced (mechanical) system equipment

A simple scheme that provides mechanical air circulation has some features:

The arrangement of inflow and exhaust channels is carried out according to the rules of the previous scheme.
A supply and exhaust duct fan of round cross-section is installed in the openings; in a warm box, a heater is used to heat the inflow. Fan parameters (power, performance) are selected taking into account the required performance; Additionally, you can install a timer and a humidity sensor.

Option for forced exhaust in the garage Source rushoros.ru

Installation of a mechanical ventilation system

Its main advantage is its independence from natural factors. There are two main disadvantages: dependence on electricity; quite high cost. Centrifugal fans provide air inflow and exhaust air volume removal.

The following mechanical ventilation systems are installed in car boxes:

Modular. The supply and exhaust complex is assembled from several independent blocks that ensure the injection and preparation of supply air, as well as the removal of polluted atmosphere. Such modules operate independently; control sensors are required for their joint operation.
Monoblock. Each such block is a complete mechanical ventilation device; it is responsible for supply and exhaust simultaneously. Among monoblock ventilation devices, models equipped with recovery plates are considered economical. Recuperation allows minimizing energy consumption for heating the supply air.

Monoblock mechanical ventilation is easier to install by preparing a single hole in the garage wall. However, an air supply complex equipped with the necessary modules is more productive.

The ability to build a complex with the required “air” characteristics is the advantage of a modular supply and exhaust complex (+)

Fresh air is filtered before entering the air ducts and, in the cold season, heated. It is supplied to the garage through air ducts through grating-covered holes made in the floor or walls almost flush with the floor, as well as in the walls of the inspection pit.

The exhaust air is taken in through an exhaust pipe, in the channel of which a fan of sufficient power is installed.

In large car boxes designed for several cars, it is more efficient to exhaust through air ducts and using a duct ventilation unit.

Combined hood

In such a system, the relative position of the channels does not play such a role as in previous versions. The supply and exhaust openings can be made, respectively, at the floor and at the ceiling, or at the same height or on the same wall. The only limitation is that the channels are not made opposite each other; with this arrangement, air flows between these points without affecting the rest of the space.

Grilles protect ventilation from rodents Source nataros.ru

The peculiarity of the combined system is that the supply channel operates in a natural mode, and the outlet channel operates in a forced mode. A fan is built into it; for a garage, this means that a process is started in which air is forcibly removed from the garage box, and fresh air from the street enters in its place.

The combined scheme has a pleasant balance of economy and practicality. It is designed for year-round operation, while costs remain minimal. It is better to give preference to devices with a plastic body and a special impeller design.

Such models are not afraid of corrosion and operate in constant ventilation mode. A suitable model is selected based on dimensions, recommended service area, and other parameters (for example, silent operation). Before installing the fan, it is advisable to insulate the air duct.

Supply fan for organizing forced ventilation Source nataros.ru

Recommendations

The criteria for installing ventilation system elements are the same for all garage compartments. Let us briefly list the main ones:

the exhaust pipe is installed under the ceiling in the diagonally opposite corner from the inflow;
the inlet inlet is located 15-20 cm above the floor and must be covered with a fine-mesh metal grille to protect against rodents;
the diameter of the ventilation pipes is calculated in advance, based on the volume of the room, conditions, location, etc.;
exhaust pipe - equal or less in diameter, but not larger than the supply pipe;
to enhance traction, you can use mechanical means, diffusers, turbo deflectors, etc.;
the exhaust outlet is located at a distance of at least 3 m from the supply inlet (for effective draft);
the supply inlet is located above the ground at a level of 50 cm;
In winter, it is necessary to insulate the hood so that frost and ice do not accumulate inside;
in winter, you should ensure that the ventilation pipes always remain free of snow and frost;
separate location of ventilation systems for garage buildings and basements.

Briefly about the main thing

A garage needs a well-thought-out ventilation system, because insufficient or ineffective air exchange can make the room uncomfortable for both the car and its owner. The situation can be corrected by organizing natural, forced or mixed ventilation.

The device of natural ventilation is considered the simplest option, which does not require financial investments and special skills. You should start by calculating the minimum permissible pipe diameter that can adequately ventilate a room of a given size. If the garage has an inspection hole or basement, the system is slightly modified.

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Equipment and materials

To install ventilation you will need the following tools: an angle grinder and a hammer drill.

Without power tools - nowhere

After calculation, pipes made of metal or plastic, as well as sealant and fans are purchased. If you want to secure the ventilation inlet and outlet, you need to purchase grilles and covers.

Why ventilate your garage?

Of course, a garage is a technical, not a residential facility, although some car owners may disagree with this statement. If a car enthusiast spends a significant part of his personal time in the garage, and even uses the basement or the garage itself to store food supplies, all the more one should be concerned about the problem of proper air exchange in such a specific room.

To begin with, there is a high concentration of exhaust gases, fuel vapors and other technical fluids. Even a short stay in such an atmosphere is extremely harmful for a person.

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Natural ventilation scheme for garage

Air exchange system in an insulated garage

Removal of substances harmful to owners

Ventilation system exhaust pipe

The second problem associated with improper garage ventilation is excess moisture. Water vapor accumulates indoors and condenses on various surfaces, including the car. As a result, the risk of occurrence and the speed of corrosion processes increases sharply; in other words, the vehicle rusts.

Vegetables, canned food, and other foods or things that do not have a place in a house or apartment are often stored in garages or cellars built underneath them. Contact with moisture, as well as exposure to technical vapors, will not bring any benefit to all these objects. And the problem can be solved simply, just take care of effective ventilation.

If ventilation is poor, droplets of condensation may appear on the walls and ceiling of the garage. This moisture then gets onto the vehicle, which can cause corrosion.

How to make mechanical ventilation

The air vortex is created artificially, through an exhaust and supply device. The mechanical scheme is considered almost ideal, especially since it can partially or completely replace the heating system. Such a system is controlled by special software that has several modes.

The advantages of a mechanical circuit in a garage also include air filtration from dust and independence from climate. When performing calculations, take into account the design and area of the garage, the presence of additional rooms, the length of the air ducts, and the number of stored cars.

By design, mechanical ventilation can be monoblock (exhaust and supply are provided by one block) and modular (the indicated functions are performed by 2 different blocks).

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How to calculate everything correctly?

Ventilation calculations in many cases require special knowledge and the use of complex techniques. If there is a desire and your wallet allows, the creation of a project can be ordered from specialists. Luckily, the garage is a small space with a simple configuration.

The dimensions of the ventilation holes are calculated using the formula:

Psech=Pgar×15

Wherein:

Psech - cross-sectional area of the ventilation hole;
Pgar - garage area;
15 - coefficient reflecting the size of the ventilation hole per unit area of the room.

Those. you need to multiply the garage area by 15 mm. According to this simplified technique for a garage of 24 square meters. m. (6*4) you will need an inlet hole with a diameter of 360 mm. These calculations are very arbitrary, since the technique does not take into account the height of the room and its other features.

In practice, these indicators can be varied. For the garage discussed above with an area of 24 square meters. m. in one specific case, two 150 mm pipes were successfully used in the inflow and one such pipe in the exhaust.

To increase the efficiency of natural ventilation, you can use additional means:

A deflector is a special cap that is installed on the edge of a vertical section of the exhaust pipe to create a rarefied atmosphere inside the structure and accelerate the movement of air masses.
A diffuser is a weather vane for the outer part of the supply pipe; wind pressure is used to operate it.
An ordinary incandescent lamp - it is installed inside the exhaust pipe and heats the air flow, accelerating its movement.

These simple devices can significantly improve the quality of ventilation in your garage.

The following article will introduce you to the general principles of calculating the power of ventilation systems, which we recommend that you read.

Garage with underground part

When purchasing a garage, the driver usually wants it to have an inspection hole. For this underground part, ventilation is also necessary. Usually, when installing it, the main attention is paid to the lower part.

The inlet pipe should exit near the floor of the garage itself. A pipe is also installed, one hole of which is located at the floor of the inspection pit, and the other at the floor of the garage. The outlet pipe is located at the top of the inspection hole.

This arrangement of ventilation holes ensures a stable air flow

The nuances of ventilation depending on the type of garage

Before carrying out ventilation, you need to consider a number of nuances

Natural ventilation replaces air masses due to the difference in temperature outside and inside the garage. To effectively move air, you need to make 2 ventilation holes. It is better if ventilation is provided before the construction of supporting structures.

To keep your garage well ventilated, you need to follow these rules:

The inlet opening must be at least 10 cm above the floor surface. To prevent debris and dust from penetrating into it, the hole is covered with a mesh. To protect against snow in winter, the air duct on the street is placed at least 30 cm from the ground.
The exhaust hole is placed in the upper corner opposite the supply hole (preferably diagonally or as far as possible from the inflow), 10 cm from the ceiling. The air removal pipe is installed 50 cm above the roof level and protected from above with a “fungus”.
Grilles are built into the gates as supply openings. In this case, effective air exchange is possible only if the size of the installed grilles is 2-3 times larger than the cross-section of the required exhaust pipe.
Removing dirty air will be better if you install a deflector. It creates an area of low pressure. To prevent condensation from appearing on the deflector, it must be well insulated.

The good thing about this kind of garage ventilation is that you don’t need to spend a lot of money on it. Of the minuses, it should be mentioned that due to unstable weather (changes in pressure, temperature and strength of air flows), it will not be possible to fully control the quality of air exchange.

Depending on the material

In a metal garage, condensation always appears on the walls, and in winter, ice forms on the roof, damaging the coating. Condensation must be dealt with, because high humidity causes metal corrosion and, as a result, rapid wear of the car.

In a garage, condensation occurs due to two factors:

Lack of ventilation or errors in its design.
Lack of room heating or poor insulation.

You can prevent condensation yourself; you just need to provide good ventilation and reliably insulate the garage. If there is ventilation and it works as it should, but condensation appears, then you need to think about cleaning its channels - perhaps they are forgotten by garbage. Over time, ventilation becomes contaminated with oily deposits and dust, which can harm human health.

Recommendation! It is better to place heating pipes in the garage immediately above the floor surface near the walls. The heated air tends to rise, completely warming the room and displacing cold air. And it will be removed from the room using ventilation pipes located in the corners of the garage.

With a basement

Using a basement for storing canned food and vegetables is only permissible if the ventilation system is working properly. Almost all ventilation systems are applicable in the basement. But usually for such an area there is enough natural ventilation, for the production of which sewer plastic pipes are used.

When planning the design you need to consider:

The cellar ventilation system should be made with a minimum number of bends and turns of pipes.
The exhaust pipe must be well insulated to prevent condensation.
The diameter of the pipes cannot be changed in any section.
External ventilation inlets must be protected with special caps to protect against precipitation.

When creating ventilation in the basement, you need to place the exhaust pipe under the basement ceiling and lead it to the roof of the garage, and the supply pipe - 0.5 meters above the floor.

With a pit

If your garage has an inspection hole, then it is advisable to ventilate it separately from the rest of the garage . Condensation often accumulates here and, as a result, fungus, mold and even insects appear on the walls.

To ventilate the pit, natural air circulation is enough. This is not difficult to do. Gaps are left along the edges of the flooring (about 10-15 cm wide). Where fresh air will enter, the gap can be doubled, which will significantly increase traction. We must remember that it is undesirable to park the car over a hole with the gap open.

What to do if you have a metal garage

Many people use garages made in the form of a metal box. To ventilate them, you need to consider the following:

They do not have an inspection hole, so there is no need to ventilate the underground part.
The garage is made of metal, so humidity and condensation threaten not only the car, but also the garage itself.
No heating. Therefore, most of the year there are sharp temperature changes that contribute to the formation of condensation.
There is no connection to the electrical network, so it will not be possible to install a forced ventilation system.

Therefore, in the case under consideration, two rectangular holes are made, covered with bars, in the front and rear parts of the garage under the roof. This will provide ventilation.

Ventilated window grilles

Additionally, it is recommended to insulate the floor (lay linoleum, concrete, lay another layer of linoleum). Such a floor will to some extent reduce temperature fluctuations inside the garage.

Calculation

Garage ventilation diagram

Before starting ventilation installation work, you need to calculate the required diameter of the ventilation ducts. This is done in two ways:

According to the formula, for 1 m2 of the area of the entire garage it is necessary to take 15 mm of pipe diameter. For example, for an area of 10 m2 it is necessary to use a pipe with a cross-section of 150 mm.
The sum of the cross-section of all holes = 0.3% of the garage area. This formula is mainly used when creating a single-channel mechanical ventilation system.

According to SNiP requirements, 180 m3 of air per hour must be supplied to a building where there is room for one passenger car; abroad this figure is twice as high.

Now a few words about the features of calculating natural ventilation. A sufficient natural flow of fresh air into the garage is possible only if you install 2 ventilation pipes - supply and exhaust. There is no need for special knowledge for calculations, the main thing is to follow the basic rules:

The supply opening is placed on the windward side of the garage, approximately 10 cm from the floor surface, the exhaust opening is 10 cm below the ceiling. They should be in opposite corners of the room.
The air duct is installed 30-50 cm above the roof. It is protected with insect mesh and fungus from rain and snow.

If, according to calculations, you require a ventilation duct with a diameter that is too large, then it is much wiser to use smaller pipes, but install 2-3 pieces.