If you have already built a cellar, but condensation constantly accumulates in it or the temperature rises, you may have incorrectly arranged the ventilation system and inflow fresh air the premises are broken. The hood needs to be thought through at the construction stage, since it will be more difficult to correct the situation later.
From this article you will learn how to properly ventilate the cellar and what work needs to be done to properly ventilate the room.
How to properly ventilate a cellar
Air circulation in an underground storage facility can be ensured naturally or artificially. In the first case, air enters through special openings, and in the second - using fans (Figure 1).
The simplest, most inexpensive, but at the same time effective method of ventilation is a supply and exhaust system. To arrange it on at different levels install two pipes, the ends of which lead to the street. Warm air is removed from the room through one, and cool air enters through the other. Next we will look in more detail at how to arrange various systems ventilation in basements.
Why is a ventilation system necessary in the cellar?
Many owners of personal plots believe that it makes no sense to install any kind of hood in the basement. There is also a misconception that the presence of holes in the walls or roof of a storage facility will disrupt the stable microclimate. In fact, everything happens the other way around.
Figure 1. Operating principle of a hood in basements In living quarters, the temperature is too high to store fresh vegetables and preparations in jars, and outside (in winter) it is too cold. In an underground storage facility, subject to proper ventilation, not only a stable temperature is maintained, but the humidity is optimal for storing vegetables. It is precisely this task that a high-quality hood successfully copes with, through which warm air is removed and supplied moderate amount fresh oxygen.
Calculation and device
For small cellars, one or several holes in the walls, led out through pipes, will be sufficient. However, if the storage facility is large enough, it is better to equip a supply and exhaust system that will effectively cope with microclimate support.
Note: In large industrial storage facilities, special fans are installed that provide a constant and uniform flow of fresh air. However, such systems are too expensive and it is not economically profitable to use them in household farming.
To determine how many ducts you will need for your basement, you need to do some calculations. First, calculate the area of the room by multiplying the width by the length. Secondly, it should be taken into account that for every square meter of area, 26 square centimeters of exhaust duct are required. For example, if the cellar area is 6 square meters, this figure must be multiplied by 26. The resulting number (156 square centimeters) will mean the total area ventilation holes. To determine which diameter will be optimal, you need to select Square root this number divided by Pi. In our example, this figure will be 14 cm. However, for better drainage warm air and the influx of fresh water, this figure can be independently increased by 10-15%.
DIY installation
After you have carried out all the necessary calculations and decided on the appropriate diameter, you can proceed to the direct installation of the system.
The installation of a hood in the cellar is carried out as follows:
- If the hood is installed in a ready-made storage facility, it is necessary to make several holes in the roof.
- An exhaust pipe is inserted through one hole and secured so that the lower edge is 10-15 cm below the ceiling, and the upper part protrudes 70-80 cm above the ground surface.
- A hole is also made in the opposite corner and a supply pipe is inserted into it. It must be secured in such a way that the lower edge does not reach the floor by 15-20 cm, and the upper edge protrudes only 20-25 cm above the soil surface.
After installation, it is advisable to cover the outer parts with canopies and grilles to prevent people from getting inside. precipitation. Checking the intensity of the draft is very simple: just attach a sheet of paper to the supply channel. If it fluctuates intensely, then the air flow into the room is good.
Ventilation diagram in a cellar with one pipe
The single pipe system is only applicable for small rooms, since for large-area storage facilities such an air flow will not be enough to support optimal temperature and humidity.
Equipment
To install such a hood, you will need a pipe, which is cut into two parts and inserted into pre-prepared channels. In addition, you will need dampers or visors so that you can independently control the removal of warm air and the intake of fresh air (Figure 2).
If the channel is discharged not through the wall, but through the roof, it is also necessary to install canopies that will protect inner space premises from the penetration of rainwater.
What pipe diameter is needed for the hood?
As a rule, products with a diameter of 14 cm are used as exhaust ducts. However, if you are afraid that such a hood will not be enough, you can choose models with a larger diameter.
When choosing, you need to consider the area of the room. Not only the diameter of the pipes themselves, but also their number will depend on this. So, for small basements one or two are enough, but for large storage rooms a more extensive ventilation system will be required.
If you choose ventilation using one channel, you should take into account that you will still have to install two air ducts in the basement. But, unlike the supply and exhaust system, they are not installed in opposite parts of the room, but parallel to each other.
Figure 2. Ventilation scheme with one channel A damper is installed on each channel to help control air exchange. IN in this case To remove warm air, it is enough to open first one channel, and then the other - for fresh oxygen to enter.
Ventilation in a cellar with two pipes
A forced system with two pipes is considered more practical and convenient. Despite the fact that its arrangement will require more effort, the finished structure will function successfully with virtually no human intervention. All you need to do is check the traction periodically.
Let's take a closer look at how to properly arrange such a hood in a home cellar with your own hands (Figure 3).
Equipment
There are several ways to provide forced ventilation using two pipes. The simplest one is to install channels of the same diameter in opposite corners of the room. At the same time, they should be installed at different levels so that warm air is effectively removed from the room, and cool air enters evenly.
The ventilation system can also be equipped with special fans that will provide a constant flow of air. However, in this case it is necessary to provide special protection for the equipment from moisture. They can also be supplied special devices- deflectors that will capture air flows and provide more intense traction.
How to determine pipe diameter
In order for the microclimate in the cellar to be stable at any time of the year, it is necessary not only to install the system correctly, but also to select pipes suitable for this purpose.
Figure 3. Operating principle of a hood with two channels In most cases, cellars in household plots are small, and a few pipes with a diameter of 10-14 cm are quite enough for them. However, when calculating their number, you should be guided by the storage area. For small rooms (about 6 square meters), one supply and one exhaust will be enough. But, if the room is larger (for example, 15-20 square meters), you will need two pairs. It must be taken into account that on average, there should be 26 square centimeters of air duct per square meter of room.
Air duct installation rules
When using a supply and exhaust ventilation system, correct installation plays a key role.
To do this, holes are made in the roof at opposite ends of the room. Their diameter must match the diameter of the pipes used. Next, an exhaust pipe is inserted into one hole. It should be positioned so that the lower end is 15-20 cm from the ceiling, and the upper protrudes 70-80 cm above the ground.
The supply unit is mounted at the opposite end of the room and installed almost above the floor (15-20 cm from the surface). The top, accordingly, rises only a few centimeters above the ground. It is advisable to cover the edges exposed outside with canopies to prevent rainwater.
Natural ventilation in the cellar
Natural ventilation of the cellar is considered simple, since such systems are easy to install, and their arrangement does not require a lot of materials. However, it should be taken into account that ensuring a stable indoor microclimate will be more difficult than when using a supply and exhaust system. In addition, if the temperatures inside and outside the cellar are the same, air circulation may be minimal or completely absent.
Therefore, if you plan to store products that require a certain temperature in the basement, it is better to put in a little more effort and install a supply and exhaust system.
Principle of operation
The operating principle of natural ventilation is very simple and is based on the difference in pressure and temperature inside and outside the storage facility. Through one pipe, located almost under the ceiling, warm air is removed from the basement, and through another, which is located almost above the floor, fresh oxygen enters.
However, it should be borne in mind that this method of ventilation is only suitable for small rooms. In large storage areas, preference should be given to forced ventilation.
Equipment
As mentioned above, installing natural ventilation does not require a lot of materials. In this case, you need to prepare two identical pipes (for installation of the system itself), as well as sheet metal or grilles to protect the system from rodents and precipitation.
Let's take a closer look at how such systems are installed and what features should be taken into account when installing them.
DIY system installation
First of all, it should be taken into account that it is necessary to provide openings for laying ventilation ducts at the construction stage. When the cellar has already been built, carry out necessary work it will be more difficult.
Natural ventilation is installed as follows:
- Holes are made in the walls or ceiling at opposite ends of the cellar.
- Pipes are inserted into them and secured.
- The exhaust hood is placed so that its lower edge does not reach the floor by 15-20 cm, and the remainder (70-80 cm) protrudes above the ground surface.
- The supply air supply is located at the opposite end of the room and is lowered almost to the floor (15-20 cm short of the floor), and the remainder is also discharged outside.
They must be covered with canopies on top, otherwise rainwater will be able to freely enter the room. It is also advisable to install small grates on the lower parts to prevent rodents from entering the storage.
Do-it-yourself forced ventilation in the cellar
In fact, forced ventilation differs from natural ventilation only in that fans are installed inside the pipes (ventilation ducts), which provide more intense air flow and removal (Figure 4).
Principle of operation
The principle of operation of forced ventilation is quite simple. In the simplest version, the fan is installed only on the exhaust pipe. This creates more active air movement through the inlet.
In large rooms, it makes sense to install both exhaust and supply fans. In this case, it will be difficult to cope on your own and it is better to contact a specialist who will help you determine the appropriate pipe diameter and fan power.
Equipment
Since forced ventilation is considered more reliable and modern, for its installation you will need optional equipment. Of course, first of all you need to prepare required amount channels of suitable diameter. After this, you should buy fans of the appropriate size and power.
Figure 4. Basic elements of forced ventilation It is also necessary to provide waterproofing of devices from moisture, which may enter the room from the outside or seep through the walls.
DIY system installation
Forced ventilation is a little more difficult to install than natural ventilation. So that you can carry out the installation yourself, we recommend using our step-by-step instructions.
Forced exhaust in the cellar is installed as follows:
- Holes are drilled in the walls or ceiling for laying channels, or voids that were previously left for this purpose during the construction phase are used.
- Pipes are laid in the holes. You can use metal, plastic or cement products.
- The supply and exhaust pipes are installed in opposite corners of the room and at different levels, as is the case with natural ventilation.
- A fan is mounted inside each pipe and dampers are installed so that the intensity of ventilation can be adjusted if necessary.
The upper parts of the pipes protruding to the surface must be covered with canopies. In the case of natural ventilation, this requirement is more of a recommendation, while for the forced type it must be observed, since rainwater can damage the fans and the entire system will be disrupted.
The video shows how best to arrange natural ventilation in the basement.
Should I close the ventilation in the cellar in winter?
If the ventilation system is designed and installed correctly, you do not have to close the openings for the winter. However, this completely depends on the climatic conditions. For example, if the temperature outside drops below -10 degrees, you need to periodically cover the openings, since the temperature difference between inside and outside will create a powerful draft, which will lead to rapid hypothermia of the storage facility.
In very severe frosts ventilation ducts It is better to close it completely, but if the temperature rises slightly, you can open it briefly for ventilation.
Which pipes are better for ventilation in the cellar?
Modern market building materials provides a wide selection of pipes that can be used as ventilation ducts. The choice is most often guided by personal preferences and financial capabilities.
Recently, most cellar owners have chosen PVC pipes or cement products. This is explained by the fact that such pipes are relatively inexpensive, easy to install, but at the same time they are resistant to fungi and have a long service life.
Do you need ventilation in the cellar in winter?
The cellar needs to be ventilated throughout the year, although some owners underground storage facilities believe that in winter time no ventilation needed. This is a common misconception, but there is still some truth in it.
If it is very cold outside (about -10-20 degrees), the difference in temperatures inside and outside becomes too large and the draft in the ventilation ducts increases greatly. If the holes are not closed in time, the cellar can quickly freeze, and fresh vegetables or the workpieces will deteriorate. Therefore, it is recommended to control the temperature in the room, and in severe frosts, completely close the channels until it warms up.
You will find useful recommendations for installing a ventilation system in the video.
Since ancient times, back then in Rus', it was customary to stock up on food for the winter. There were no giants then Food Industry, and if people went to the market, they found there exclusively goods from the neighboring cellar. People built dugouts, dug basements without any utility networks and waterproofing. As a result, the premises were flooded with water and food was lost. About devices such as cellar ventilation and waterproofing the room were out of the question. The people were not yet so educated and developed.
Now everything is different. Knowledge in the design and construction of basements allows you to create best premises for storing food. When calculating and designing ventilation devices in the cellar Standardized norms and rules apply. They allow you to competently and wisely organize the basement from the inside, provide an ideal microclimate for storing vegetables and preserve the harvest until next year.
Cellar ventilation: basic requirements
According to its purpose ventilation device for cellars and basements designed to provide moderate and stable levels of humidity and air temperature. In addition to ventilation, several other factors influence these indicators.
Therefore, immediately before construction, it is necessary to understand and provide for all possible factors that, during the operation of the premises, may affect the climate of the basement.
Only taking into account all the factors that can influence the functioning of the cellar will help achieve a certain climate. If something is missed, then you should not scold the ventilation or place excessive hopes on it. Undoubtedly, it is capable of maintaining the desired microclimate, but it cannot eliminate the wetting of the wall.
If the basement has a favorable location, good hydro- and thermal insulation, then you can proceed to the design and installation of ventilation.
As in most residential and production premises general purpose, ventilation in the basement has a source of air inflow from the environment and a device for the outflow of moist, polluted carbon dioxide masses.
Basement ventilation systems
The most common option for constructing a basement involves locating the cellar under the main rooms of a private house. In this case, two options for the exhaust device are used:
- two-channel;
- single channel.
The first one is used most often. It has a number of advantages in terms of servicing a larger cellar area.
Two-channel ventilation device
The ventilation technology with two points of inflow and outflow does not have any difficulties in installing air ducts.
Basement ventilation ideal development the construction process of a house should be calculated at the start of construction. This way you will get by with less financial and labor costs.
Supply air duct pipe.
The inflow device ensures the flow air masses from the environment, by taking air through the intake opening (vent). The vent is most often located near the side wall of the main building - the elevation above the level of the house blind area should be 20-30 cm.
The hole in the pipe itself is covered with a ventilation grill. If necessary, a grating can be provided. The air duct is laid through the base of the house, the basement floor and introduced into the basement. Outlet ventilation stretch almost to the floor cellars, retreating 15-20 cm. Thanks to this arrangement of the ventilation duct, cool air from the street enters the air duct, passes through it and enters the basement near the floor. After this, it is gradually heated and displaced upper layers warm and humidified air from the basement through the exhaust duct. 
System for the outflow of contaminated masses.
It is located in the opposite corner of the cellar room, diagonally relative to the supply pipe. The main principle is the need to capture heated air. This is achieved by placing the pipe entrance right under the basement ceiling (10-15 cm from it). Next, the exhaust duct passes through the ceiling of the main building, through the attic to the roof.
Depending on the shape of the roof and the prevailing wind rose, it is necessary to achieve conditions under which the wind will be directed towards the previously installed one. A deflector is needed in any case, as it protects the pipe from atmospheric precipitation entering it. It also additionally creates negative pressure under the cover, due to which the air flow in the pipe increases.
The longer the exhaust duct, the stronger the flow of exhaust air in it.
The exhaust duct should be equipped in several layers to create the necessary insulation. To do this, at the stage of planning the premises and utility networks of the house:
- install brick or wooden well for pipe cellar ventilation;
- choose a place to lay insulation between the well and the pipe;
- wrap the pipe itself with a special insulation that will not absorb moisture.
It is necessary to insulate the exhaust air duct in order to prevent air condensation due to sudden cooling during the cold period.
Regarding the last two points, it is worth noting that only double thermal insulation can provide resistance to duct freezing. If the region where the house and basement are located suggests abnormal low temperatures, you additionally need to create an air gap between the main insulation and the insulation on the pipe itself. This solution will significantly reduce the thermal conductivity of the channel as a whole.
Single channel ventilation
In rare cases, when the cellar area is less than 5 sq.m., it is possible to combine the oxygen inflow and outflow channels in one pipe. This is the basic principle of operation of this system and the main difference from a two-channel arrangement. The pipe is separated by a partition, through which two circulation channels are obtained: one for inflow, the second for exhaust.
Natural or forced exhaust?
To deal with this issue, you need to conduct an experiment with an existing natural ventilation in the cellar under the house. To do this, you will need to bring a thin sheet of paper to the outlet holes of the channel in the basement and determine, by the swaying of the sheet, the presence of movement of air masses.
This experiment is suitable for basements with an area of up to 10 sq.m. If the basement is more than 10 sq.m., then, even if there is oxygen movement inside the room, the efficiency natural exhaust may be in doubt.
For a relatively large room, you need to purchase a hygrometer. This device measures air humidity. The presence of a thermometer is mandatory for any size basement.
To determine the degree of ventilation, it is necessary to install a device that measures air humidity. It should be installed approximately 1.5 meters from the floor.
This is important, since the humidity will be highest near the ceiling. But vegetables are mostly stored on the floor. Therefore it is necessary to measure average value room humidity.
At high hygrometer readings (over 85-90%), it is necessary to install a forced ventilation schemes in the cellar. 
Forced (mechanical) exhaust system
Remake DIY ventilation in the cellar won't be difficult. To do this, you need to install axial fans inside the air ducts. This will increase circulation. For the supply duct, the fan is placed at the entrance on a protective grille. Accordingly, the exhaust duct is supplied with a fan directly at the entrance to the basement.
When you hear the word “basement”, many probably have associations with a dark, damp and cold room in which food or something not very necessary is stored. This is the microclimate that is often maintained in cellars. And it is this that greatly harms both the building itself and what will be stored there.
To ensure a favorable microclimate in the basement, you need to organize a properly functioning ventilation system in it. We'll look at how to do this below.
We will consider the arrangement of ventilation in the basements of small buildings: in a private house, barn, garage.
Is ventilation needed in the cellar, and why? (+video)
Yes, it is necessary and mandatory. Any room (not only residential, but also basement) needs air exchange.
In the basement, the ventilation system maintains normal humidity. In the basement it increases very quickly, especially if:
External waterproofing and insulation of the basement are absent or poorly performed;
it rains heavily;
there are cracks in the walls of the cellar (through which moisture can penetrate inside);
Due to the strong temperature difference, condensation forms on the walls inside.
What happens if there is no ventilation system in the cellar, or it does not work well?
If the ventilation system in the cellar does not work at all, or does not work well enough, the cottage owner will face the following problems:
the air in the basement will be damp and stale - being in such conditions will be both unpleasant and harmful for a person;
Will deteriorate quickly due to humidity interior decoration basement (if there is one) and flooring on the floor of the first floor;
the basement walls and the ceiling between the basement and the first floor will collapse faster;
the floor on the first floor may be wet (if the ceiling is thin and there is no insulation and waterproofing);
if food is stored in the cellar (for example, potatoes, apples, carrots, and other crops), or products made of wood, fabric, metal, they will deteriorate faster due to humidity;
V rooms on the first floor may have an unpleasant odor due to food rotting in the cellar).
Basement ventilation standards
SNiP regulates only the installation of ventilation systems for apartment buildings. SNiP 31-01-2003 “Residential multi-apartment buildings” contains the following information:
In the external walls of basements that do not have exhaust ventilation, vents with a total area of at least 1/400 of the basement area should be provided. Vents should be evenly located around the perimeter of the external walls. The area of 1 vent must be at least 0.05 m².
The air exchange rate should be 1.5. That is, if the basement area is 100 m², then in 1 hour the ventilation system must move at least 150 m².
These same standards can also be relied upon when constructing basements in low-rise buildings.
How to make cellar ventilation with your own hands: types of schemes
Any ventilation system consists of 2 components: the influx of fresh air from the street and the removal humid air from the premises.
The process of air passing from the street into the basement and then removing it from there can be stimulated in 2 ways:
Natural. Air exchange occurs due to pressure differences. The difference is created due to the different heights of the pipes. The exhaust pipe must be installed above the roof ridge. The method is not very successful - such ventilation will work unstably and will largely depend on the weather.
Forced. The best scheme any ventilation system is precisely a mechanical design: when air exchange is created by a fan. For a basement, 1 fan standing on the hood is enough.
Below we will consider in more detail how to build both types of ventilation systems.
Natural
For natural ventilation, 2 pipes are supplied to the room (one for supply, the other for exhaust). Their openings should be located at different heights: supply - low, exhaust - as high as possible (but always above the roof canopy).
Its huge disadvantage is that productivity (the amount of air passing through the basement) is highly dependent on weather conditions. If it is cold and windy outside, the air exchange will be good. If it's warm and there's no wind, it's bad.
How to properly organize natural ventilation yourself:
For inflow, vents are drilled around the perimeter of the basement. If the room is completely buried in the ground and does not protrude above the surface, you will have to make a pipe leading from the surface.
For exhaust, a second pipe is installed on the opposite side of the room. It is installed above the roof ridge so that nothing obscures it from the wind.
It is advisable to install a deflector on top of the exhaust pipe to improve draft. The supply pipe is covered with an umbrella (and if it is vents, with a ventilation grille).
P forced (+video with example)
A more stable and efficient option for ventilating damp rooms.
Do-it-yourself organization looks like this:
An influx is made: through vents (if the basement “protrudes” above the surface) or through a pipe (if the cellar ceiling is below surface level).
For exhaust, a pipe is installed on the side opposite the inflow. One end of it should be under the basement ceiling, the other should go outside. It is not necessary to display it above the roof, but it is possible.
A fan is installed in the exhaust pipe, which will drive air from the room to the street.
If you remove the pipe as in the first case (above the level of the visor), then the ventilation will work even natural principle, even if the fan is turned off. If the hood is not vented above the roof, it will only work when the fan is on.
Where should the inlet and outlet openings be located?
The location rules are:
The inlet must be located opposite the hood.
If the inflow is organized through a pipe, ideally it should extend to a level of approximately 0.3 m above the basement floor. If air flows into the upper part of the room (as happens when installing vents), the air exchange in the lower part may be weak or even absent.
If the inflow is organized through vents, they should be located around the perimeter of the room so that there are as few “dead” areas as possible (near which there are no inflow points).
The exhaust duct opening should be located immediately below the ceiling so that the air does not stagnate in the upper part. Ideally this should be an angle. If it is not possible to make a ventilation duct in a corner, then it is advisable to place inflow points in the corners (so that there is also air movement there).
Nuances of arranging a ventilation system depending on the size of the basement
Usually in private houses (both in cottages and dachas) basements are not very large in area and volume, and consist of 1 room (that is, they do not have rooms). In this case, you can use all the data and rules that are given in this article.
But if you have a large basement, or if it is divided into several rooms, or if it consists of several “floors,” then the ventilation system should be more thoughtful.
The main nuances in brief:
If your cellar is divided into rooms (even if there are 2 of them), each of them should have its own inflow point and a “path” for removing air (at least 1 each). Both supply and exhaust can be organized either through a ventilation duct (run 1 pipe across the street for supply and exhaust, and inside - distribute them throughout the basement), or make vents in each room.
If your cellar has more than 1 floor, a ventilation system must be installed in each of them. In this case, it is recommended to use only mechanical ventilation(and it is advisable to install a fan on the supply side as well).
If the basement consists of 1 room and is large in area (conventionally - from 20-25 “squares”), then it is advisable to use at least 2 inflow points. If you don’t want to make several holes in an existing building, you can make 1 hole, run a pipe through it from the street inside, and run it along the wall. In the pipe - make several holes at a distance from each other (so that air is supplied through them to different parts of the basement).
Example of a ventilation system for a basement at a depth of 3.5 meters (video)
Service Questions
Below we list several basic issues related to improving and maintaining the system.
How to automate the system?
The microclimate (humidity level and temperature) in the basement can vary over a wide range - since no one constantly controls it, heaters and other climate control equipment are usually not installed in the basement.
Therefore, for more efficient and economical operation of the ventilation system, it is worth automating it.
Automatic ventilation is organized using sensors:
Temperature sensor. Useful in winter to avoid manually closing the ventilation in cold weather. The temperature sensor can control the motorized damper, closing it, or the speed of the exhaust fan, reducing it or turning off the device completely.
Humidity sensor. Useful at any time of the year (in winter, moisture can penetrate through the soil, in the warm season - due to rain). The humidity sensor can control the exhaust fan by increasing or decreasing its speed. If the humidity rises, the fan will spin harder, removing more air. And vice versa: if the humidity is normal, the fan slows down or even stops so as not to waste electricity.
Is it worth closing the cellar ventilation for the winter? (+video)
In winter, basement owners are faced with the question: should they close the ventilation ducts during frosts, or leave them open?
The bottom line is this: at low temperatures, the difference in air pressure outside and indoors increases. Because of this, air exchange accelerates (more air passes through the ventilation system). And since the air is frosty, and there are usually no heaters in the basement, the room quickly gets cold. This occurs at temperatures from -5-10º and below, especially if the house is located in an open area.
It turns out that with open ventilation ducts in severe frost, owners are faced with the following problems:
food stored in the basement may freeze;
with the onset of cold weather, rodents and insects look for a warmer shelter, and through vents they can enter the cellar;
it is difficult to be in the basement without warm clothes (due to the low temperature);
the exhaust pipe may become clogged with frost (since the air in the basement is warmer and more humid, when rising through the pipe, moisture from it can condense on the walls, and the walls from the inside will gradually become overgrown with frost);
cold can be transmitted through the ceiling to the rooms on the first floor.
To prevent this, you need to either install a heat source (heater) in the basement or cover the ventilation ducts. There is no specific temperature at which it is necessary to close the cellar ventilation (but if the temperature during the day remains stably below zero, and at night drops below -5º, then you need to pay attention to the ventilation openings). But there is also a serious nuance: you need to look not at the thermometer, but at the microclimate in the basement.
Depending on the microclimate, the following measures should be taken:
If the weather is rainy and there is damp or condensation inside(a common problem in the fall, especially in November)- That ventilation must be left open. If you close it, the humidity in the basement will increase even more, and this will lead to mold.
If there is no condensation and the humidity is normal, but frost appears around the ventilation holes, they need to be covered.Since precise adjustment cannot be achieved, you can first cover the holes by 50%, and after 1-2 days see again if there is frost on them. If there is, then you need to cover the ventilation even more, leaving a small gap.
What exactly needs to be blocked - air flow first(vents or supply ventilation ducts). Ideally, the supply openings should be adjustable: a damper or adjustable blinds. If this is not the case, the owner will have to close the holes with improvised means. The easiest option is to use a sheet of metal that is attached to ventilation grille wire.
How to check cellar ventilation?
If you bought a house and do not know the condition of the ventilation system, or have not been in it for a long time, or simply have not been interested in the operation of the ventilation before, it is recommended to check it.
How to improve air exchange?
If the basement ventilation system is not working well enough, you can correct the situation in the following ways:
Clean the exhaust duct and vents (or supply pipes). Over time, ventilation ducts can become clogged with leaves, poplar fluff and other small debris. This can either worsen or stop air exchange altogether. Therefore, if there are problems with ventilation, it must first be inspected.
Install the fan in the exhaust duct. Most effective way: forced extraction is always more effective than natural extraction.
Extend the exhaust pipe if possible. The higher the exhaust pipe, the greater the pressure drop, and the better the air exchange will be. The method is not very convenient and simple. It can help if there is some kind of “obstacle” next to your building: more high buildings, or tall trees, or the house itself is in a low place.
Install a deflector on the exhaust pipe. This is easier to do than extending the pipe.
Most The best way increase traction - check condition first ventilation pipes, clean them as necessary, and then install a fan in the exhaust pipe.
Which pipes to choose for the cellar ventilation system?
Selection rules:
Material. D For ventilation ducts you can use either plastic pipes, or galvanized. Galvanization is slightly more expensive than plastic.Since there is not much difference for small rooms, you can take what you like.
Section shape (round or rectangular). Rectangular ones can be mounted end-to-end along the walls - which is convenient if the cellar is very small.
How to calculate a ventilation system for a cellar?
The calculation must be carried out to determine 2 indicators:
The total air flow in cubic meters that must pass through the basement in 1 hour. Based on this value, it is necessary to select the fan power if the exhaust ventilation is mechanical.
Cross-sectional area of air ducts. Based on this value, it will be possible to determine the diameter of the exhaust pipe.
Calculation of air flow (+ determination of fan power)
Basement or cellar ventilation is an important component competent operation premises. Without an air exchange system, dampness actively spreads and excess moisture forms. In cellars and basements not only canned goods are stored, but also stocks of vegetables and fruits, which tend to “breathe”. A lack of fresh air inflow and humid air outflow invariably leads to the accumulation of condensation.
When building a plinth and foundation, mistakes are often made in terms of installing a waterproofing layer. In this case, the walls can accumulate dampness from the external space in their structure and absorb it from the soil. It is quite simple to eliminate all the listed omissions and undesirable manifestations - organize effective ventilation of the cellar or basement apartment building, For example.
- Strict temperature regime. It is customary to arrange the cellar in such a way that the room is in contact with external wall residential building.
- Lack of light source. This condition is mandatory. It is allowed to turn on the lighting for a short period.
- Influx of pure oxygen. The condition is easy to implement if the ventilation in the basement functions efficiently and copes with the removal of dirty air.
- Humidity conditions. The humidity level in the cellar should not fall below 90%.
- The air exchange system for the basement is installed at the construction stage of the facility itself. This approach simplifies the supply of channels to the walls, where elements of the ventilation system will subsequently be placed. The location of the pipes must be indicated in the design documentation.
- Pipes for air supply and exhaust must be of the same diameter, which will ensure uniform oxygen circulation around the perimeter of the room. If we are talking about a ready-made basement, where it is necessary to quickly get rid of damp air, it is permissible to use an exhaust pipe of a slightly larger diameter. The reverse order is not possible, since there is a high risk of oxygen retention and gas contamination of the cellar.
- The ventilation system pipes are usually located in opposite corners of the room. It takes some time for the fresh flow to pass through the entire room and then exit to the street.
- The air duct hole is made under the ceiling, since warm masses rush upward, which in turn provides the room with constantly pure oxygen.
- Experts strongly recommend installing the exhaust pipe 1.6 m above the ridge of the cellar, which is necessary to generate sufficient draft. As for the pipes themselves, the most suitable option– sewer plastic solutions.
- If the facility is located under a garage or residential building, the total number of turns of the duct system is kept to a minimum. The ideal option is an absolutely flat and straight pipe of the same diameter along its entire length.
- From the street side, the base of the supply pipe is located slightly above ground level. The outlet channel must be covered with a protective grille to prevent small debris, birds and animals from entering the system.
- Pipes installed in a strictly vertical position require protection from precipitation. The simplest way is a metal umbrella, but a more complex one, but much more functional, is
- The humidity level in the room is reduced by regular ventilation. In summer it makes sense to open dampers, hatches, etc. Due to the temperature difference in the cellar, ventilation will be provided.
- To increase humidity, the practice of spraying water with a spray bottle is used. You can install a box with moistened sand or wet sawdust in the room.
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Basic requirements for carrying out work on arranging cellar ventilation
Almost all modern private houses are built with a basement. This is one of the most effective ways obtaining several tens of square meters usable area without damage to the main residence. It is common practice here to set up gyms, saunas, storage rooms and food storage areas. Even in the 21st century, most basements are used as cellars.
When arranging them, you must adhere to certain recommendations:
The key point is high-quality basement ventilation and the presence of an appropriate system in principle. Effective air exchange will not only allow food to be stored much longer, but will also eliminate the risk of mold and mildew formation, which often happens in high humidity. Functional cellar ventilation is an important component necessary for creating optimal storage conditions for vegetables, fruits and other products.
How the system works
The operating principle of the system is based on the basic laws of physics. Taking a close look at the ventilation diagram in the cellar, we can state the fact that it is designed extremely simply, but at the same time reliably.
To organize a complete system, it is enough to provide 2 ventilation holes for the basement. One of them is necessary to remove excess fumes and air from the room, and the second is to ensure the flow of clean and fresh oxygen. To provide optimal efficiency such a system requires two pipes, supply and exhaust.
Important condition quality work ventilation in the cellar - the correct location of the air ducts, especially with regard to their placement above the soil level.
Ventilation in the cellar under the house
An equally important stage is the installation of pipes optimal height from the floor and their subsequent removal to the external space. Incorrectly placed ducts can lead to too much large volume air, which is extremely undesirable for fresh food and vegetables stored on shelves. Too small a pipe diameter will not allow you to quickly remove musty air masses from the room.
Proper ventilation cellar requires careful preparation, development of design documentation and study of recommendations for installation work:
In any case, the pipe located outside must be insulated, which will help avoid the formation of condensation on the walls of the air duct during the cold season.
A properly organized ventilation system is supplemented with dampers, through which you can regulate the volume of air supply and exhaust, which is very important for maintaining an optimal microclimate.
Types of cellar ventilation systems
Before you make ventilation in the cellar, you need to decide on the type of system that will be equipped in the room. It can be either forced or natural. The choice in favor of one option or another is determined by the features of the basement layout and its total area.
Forced air exchange system
Fan usage in the system
The main feature of such a ventilation system is the automatic supply and exhaust of air, which is achieved through fans located in the pipes. Her work does not depend on the vagaries of weather and external factors. In the simplest version, it is enough to place the fan near the exhaust duct. Thanks to this design, artificially rarefied air is formed in the room in a few minutes, which is actively removed to the outside space.
For large basements with complex architecture, it makes sense to install 1 fan on both the exhaust and supply ducts. Naturally, without the help of a specialist who can advise optimal solutions for a coordinated and uniform output and intake of oxygen is indispensable.
Forced ventilation of the cellar in the garage
Natural air exchange system equipment
The operating principle of natural ventilation is based on physical laws. Temperature and pressure are different indoors and outdoors. The effectiveness of such a system depends on the proper placement of air ducts. The exhaust vent should be located 10-20 cm below the ceiling area, and the supply vent should be 25-30 cm from the floor.
For a small basement in a residential area country house this is quite enough, but in all other cases it is better to resort to a compulsory system.
Calculation of ventilation duct diameters
So, how to make ventilation in the basement? – The task of primary importance is to select pipes of the required diameter. On average, 26 cm2 of air duct area is provided per “square” of the cellar. If we are talking about a small square room, the dimensions of which are 3 x 3 m, then the diameter of the pipe is calculated in the following sequence.
S= 3 x 3 = 9m 2 – total basement area
T = 9 x 26 = 234 cm 2
The radius of the duct is calculated using the formula:
R = √ (T/n) =√ (234/3.14) ≈ 8.6 cm
Pipe diameter (for inflow):
DP.≈ 170 mm.
Experts advise choosing a pipe option with a 15% margin for the exhaust duct. Respectively:
DV. = Dп. + 15% = 170 + 26 = 196 mm.
Before installing all elements, it is necessary to make calculations. Only in this case will the system provide optimal conditions in the room.
Ventilation installation
Having completed the preparatory activities, you can proceed directly to installing the system. There are rules that should be followed, regardless of whether the air exchange is natural or forced.
Step-by-step instructions on how to properly ventilate a cellar:
Do-it-yourself ventilation in the cellar begins with the selection of material; in this case, installation will be carried out using asbestos and plastic pipes. We make two holes in asbestos, one in each pipe (to place plastic pipes in these holes). The holes must be equal to the diameter of the plastic pipes.
To make holes, use a drill or screwdriver.
Next we install the pipes. The lower pipe will carry inflow, and the upper pipe will carry out outflow. The outflow pipe is installed at a distance of at least 1.5 m above the surface of the ground or roof. And the supply air is at a distance of 20 to 50 cm above the surface.
We bring plastic pipes into the room, while we lead the supply pipe to the far corner of the basement. We leave the distance from the floor the same - 20-50 cm. As for the exhaust pipe, it is better to mount it as high as possible to the ceiling, since that is where the warmest air is located and thus it will be easier to bring it out.
Pipe on the left is outflow, pipe on the right is inflow
We also cement outside.
Cellar Depth 3.5 meters Ventilation system
Nuances of maintaining an optimal microclimate
To maintain an optimal microclimate in such a confined space, it is necessary to follow a certain sequence of actions.
An automated installation makes it much easier to maintain an optimal microclimate in the space. If necessary, it can be quickly adjusted at your own discretion.
Drying the cellar
An important aspect of ventilation measures is drying the cellar. Experts identify several effective ways to eliminate excess moisture. It is better to carry them out in the summer, when there are no foods, vegetables and fruits in the room. Hatches, openings and dampers are opened completely and the space is left in this form for at least 3-4 days. (effective in warm, dry weather) We will also tell you about several forced drying options.
Hygroscopic substances
In 80% of cases, to dry a room, it is enough to confine yourself to installing a small box in the cellar with a large table salt or lime. Their main feature– hygroscopic structure, thanks to which they actively absorb unwanted moisture from the surrounding space.
Installation of a domestic fan
Domestic fans are found in every residential building. They effectively eliminate excess moisture. The device itself is placed in the central part of the basement and left on for 3-4 days. All hatches and dampers are first opened completely.
The basement is an integral part of a modern private house or cottage. It serves to house communications for heating and water supply systems, and can be used as a garage, workshop or vegetable storage. In any case, the basement needs to maintain a given level of temperature and humidity. Dampness negatively affects the safety of agricultural products, leads to the appearance of mold, destroys the walls of the house and negatively affects other objects. Properly equipped basement ventilation will help solve this problem.
Note positive points from the use of ventilation systems in the basement and ground floor: 
- Comfortable microclimate in the house, there is no feeling of dampness on the ground floor;
- Possibility to arrange a storage room, in which a constant temperature and moisture content in the air is maintained;
- Increased service life load-bearing structures a residential building or cellar, especially if they are made of wood;
- Operation of gas and heating equipment is not possible in an unventilated area for safety reasons;
- A dry basement will never cause mold spores., causing ARVI, allergies and asthma.
Kinds
All types of ventilation are divided into several types, depending on its purpose, complexity of arrangement and principle of operation. But the principle of operation of any of them will be based on the laws of physics on the movement of air masses. Cold air goes down and warm air rises.
Natural supply ventilation
The simplest, vent system in the foundation or basement. It is installed during the construction of a house and consists of small holes in the upper part of the basement.
If the basement is located below ground level, then the hood is equipped with plastic or asbestos-cement pipes with a diameter of 10-15 cm. They are brought above the surface to a height of 30 cm and covered with grates to prevent debris and rodents. This method is natural and depends on fluctuations in street temperature, wind strength, and humidity.
When calculating its throughput, 1/400 of the total area of the basement is taken - this way we get the total area of all vents.
The holes should be located on the leeward side, least susceptible to precipitation. At home with complex shape foundation and located in low-lying areas can have up to one hole every 3-4 meters. We close the vents with gratings on the outside.
This inexpensive option well suited for ventilation of garages and non-residential basements or as additional means to the main ventilation system.
Natural exhaust ventilation
Supply and exhaust type. For proper operation, you will need to install two pipes for ventilation, and the device supply and exhaust ventilation looks like that.
- The first pipe is located under the very ceiling of the basement and is designed for the outflow of warm air. We place the exhaust pipe as high as possible, preferably at the level of the roof ridge. This is necessary to ensure good traction. The part of the pipe that is located on outdoors, must be insulated to prevent freezing in winter and covered with a canopy from precipitation.
- The second pipe for the supply of fresh air is located at a height of 30-40 centimeters from the floor level, and we place its entrance on the street a meter above the ground and cover it with a grille. Convection will occur due to the temperature difference between the street and basement air. Such a system will work most effectively when the supply channels are distributed across to different parties basement
All natural exhaust ventilation systems have one drawback - their dependence on weather conditions and prevailing winds. It will not work if the temperature in the basement and outside are equal.
Forced
It is used if natural supply ventilation cannot cope or there is no physical opportunity to use it. Typically used in the following cases:
- Basement area from 40 m2 or has several rooms isolated from each other;
- High humidity premises when condensate in the exhaust duct freezes in winter and impairs the permeability of air masses;
- The architecture of the house does not provide for high ventilation pipes;
- The basement is equipped with a sauna, cafe, Gym, workshop or other source of unpleasant odors.
The forced supply and exhaust ventilation device has a system of channels and fans that circulate air.
The main condition is to make the air constantly circulate, which is ensured by the synchronous operation of exhaust and supply fans. Their number is calculated depending on the volume of the cellar or basement and the throughput of the air ducts.
Supply and exhaust ventilation with heat recovery
For ground floor, in which it is planned permanent residence It is not enough to simply install a forced ventilation system. The room must be insulated and waterproofed. The issue of heating and heating is also resolved.
Increasingly, supply and exhaust with heat recovery is being built into such schemes.
Well-heated air enters the exhaust pipe, and in order not to release ready-made calories into the atmosphere, the air is passed through a special ceramic recuperator. When heated, it gives off heat to fresh air. The air flows do not intersect. The efficiency of such a device is 50-90% depending on the design of the heat exchanger. All heat recuperators are very reliable and do not require additional service and can last for decades.
Equipped with moisture traps, dust filters, sensors that monitor humidity and air temperature. For a residential premises, these indicators lie in the range of 50-65% relative humidity and 18-220C. Such systems are most often found in “smart homes”, and their installation is complex and should only be carried out by professionals.
Supply and exhaust ventilation device
Now let's look at how to make ventilation in the basement. The easiest way would be to make ventilation in the cellar or basement of the supply and exhaust type or forced.
First, let's do the calculation.
For 1 m2 of area there should be 25 cm2 cross section air duct.
As the ceiling height or humidity increases, the diameter of the duct increases. Wooden box can be divided into two halves for supply and exhaust ventilation, but it is best to use plastic pipes or metal corrugated boxes.
Wooden ventilation parts must be treated against mold and painted.
The supply and exhaust ventilation device can be supplemented with a deflector on the roof of the house. It will create additional vacuum in the pipe and improve the release of warm air. 
A controlled forced system will be much more effective with comparable labor costs. To do this, we will need special duct fans that operate on a voltage of 36 V. This feature is associated with the category of all basements that allow the use of only such currents.
Therefore, a transformer is installed in the electrical panel, reducing the voltage from 220 V to 36 V. And the wiring must be laid in cable channels. These and other rules can be found in.
For small rooms, only one such fan per exhaust arm will be sufficient. The flow of fresh air will be carried out due to the vacuum in the basement. But the efficiency of the system will be much higher if you install a second supply pump and combine their work into one control panel. 
Now on sale you can find programmable control panels with temperature and humidity sensors, and the duct fans themselves are available in all sizes and are compatible with almost any ventilation ducts. For convenience, they are already built into the body, have a protective grille and replaceable filters.
As pipes for ventilation ducts V own home It is preferable to use PVC. They are strong and lightweight enough to be attached to walls and ceilings using regular dowels. They are not afraid of moisture and temperature changes, and the cost is lower than steel structures.
Condensation will always form in the exhaust ventilation ducts, which must be removed periodically. To do this, you can provide a special hole for draining water. Excess moisture leads to corrosion metal structures and increases the likelihood of the air duct freezing in winter. If this happens, you should definitely clean and defrost the channel.
Functionality check
Determining air circulation is quite simple. You can use an open flame for this. alcohol burner or candles or attach a sheet of paper to the opening of the exhaust duct. Good hood will hold the sheet securely. A thermometer installed in the area of the supply air duct will not do any harm.
The following signs indicate poor ventilation in a basement or garage:
- The appearance of condensation on the walls, and humidity exceeds 95%. The permissible maximum humidity for storing workpieces and crops is 85-90% at a temperature of 3-40C. For residential premises and garages, humidity levels should not exceed 40-50%;
- Mold and fungal formations on the walls and ceiling;
- Unpleasant smell indoors and heavy stale air;
- Sudden changes in temperature they talk about an incorrect supply and exhaust ventilation device or errors in calculating the channel cross-section;
- In warm weather, condensation may not be noticeable, but in winter the walls will be covered abundantly with frost;
- Can accumulate in the vegetable cellar carbon dioxide. You can identify it by a dying candle or match. In this case, it is necessary to open all the dampers and ventilate for 24 hours, without going into the room without protective equipment.
The installation of ventilation systems will be much more effective if, together with it, measures are taken to maintain the microclimate:
- Periodic ventilation with the opening of all doors and hatches. This requirement is especially relevant for cellar owners. It is best to do this in the summer, and remove all wooden objects from the cellar;
- Treat walls regularly lime or special compounds. They will protect against mold and unpleasant smell in room. Sample recipe this composition: per bucket of water 3 kg of lime and 50 g of copper sulfate;
- You can combat excess moisture in the air with a sandbox., sawdust, salt, quicklime. Periodically, the box is taken out and thoroughly dried in the sun. In the cellar, you can leave the hole unlocked and cover it with old blankets or mattresses to improve air circulation;
- Installation helps additional source heat ( small stove, brazier, heater, lamp) or just a burning candle;
- Waterproof your basement or cellars with bitumen compounds;
- Install adjustable dampers on the supply and exhaust ventilation. With their help, it will be possible to eliminate drafts and freezing of the basement in winter;
- If the cellar is located in a garage, then it should have a separate ventilation system. High humidity vegetable cellar contraindicated in a car;
- Install a regular home fan.
How much does it cost to do ventilation?
Providing a good microclimate in the basement is inexpensive. Simple options can be made from construction waste and scrap materials; more complex ones will require additional investments.
The cost of the entire system will be influenced by the following factors:
- The area of the basement and the height of the entire building. Using these parameters, the number and size of air ducts are calculated, which will make up a significant part of the entire project;
- Air box material. PVC is cheaper, but has limitations on the size and maximum diameter of the pipe. Galvanized steel is more reliable and allows ventilation of any degree of complexity and configuration, but is much more expensive, heavier and may require special equipment;
- Degree of automation (a simple duct fan costs from 2000 rubles, a switch from 1400 rubles);
- The presence of complex and expensive additional devices - split systems, recuperators, dehumidifiers, hygrometers and sensors (the cost of such a turnkey system can exceed 100 thousand rubles);
Ventilation in the basement is important both for the safety of the food stored there and for the well-being of the entire home. The simplest options can be made independently or laid down during the construction stage. More complex types of ventilation will require special skills and experience. In any case, this system must always be in good working order and promptly serviced.
