Matter how well functioning ventilation in the cellar depends on the safety of objects placed there, and sometimes well-being and health of the hosts. To create a properly working air exchange system requires some understanding of the physical processes and knowledge of the technology of the device.
We'll show you how to arrange the exhaust air removal system of the underground facilities and to ensure the supply of fresh portion of the street. In the present article to familiarize detail proven options and ways of implementation. Taking into account our recommendations you can perfectly equip cellar.
The content of the article:
underground space ventilation task
- Compliance with the temperature
- Solution of the problem of excessive amounts of moisture
- Lowering the concentration of hazardous gases
Theoretical Foundations of moisture removal
- Physical Description The processes of condensation and evaporation
- Drainage of underground rooms in the summer
- Moisture freezing in winter
Technical moments ventilation device
- Placing ducts and their servicing
- Natural and forced air circulation
- The removal of moisture by condensing zones
- Conclusions and useful videos on the topic
underground space ventilation task
The cellars used for long-term storage of items with special requirements to the environment. The temperature in the closed underground spaces are almost always kept in the range from +5 to + 12 degrees Celsius.
humidity indicators may significantly vary, generally from the external environment. With ventilation possible regulation of these parameters to the required values.
Cellar, storage room for billets and long products are stored, arrange in the basement and cellars of houses, detached buildings, in the lower tiers of garages. All options require ventilation organization
For the formation of the normal air partially or completely submerged in the ground is necessary to provide room air flow
For outflow entering the basement or cellar required air exhaust openings or venkanala device. Their amount should ensure complete removal of air incoming through the supply opening
By type of motivation system of air flow for ventilation of cellars are divided into natural and forced. In natural air mass moves according to the laws of gravity in the forced air flow is stimulated fans
Flawlessly serving ventilation will take the excess moisture from the cellar or the basement, it prevents the appearance of mold, fungi and their consequences - demolition operations,
The ventilation system is needed to remove stale air and accumulate toxins that can pose a threat even when the short-term visit to the cellar
Regular winding basements and detached cellars eliminate condensation, due to which the perishable products and the workpiece
Ventilation system prevents the accumulation of hazardous and toxic substances that accumulate in enclosed areas without ventilation stable
Ventilation cellar in the basement of the house
Supply opening to the basement or cellar
Ventkanal exhaust ventilation system
Ventilation elements forced ventilation
Extension of service building structures
Ventilation for optimum microclimate
Compliance with the temperature
Temperature conditions correctly built and insulated cellar formed by the heat exchange between the walls, the floor and the air located therein. The ceiling is usually insulated, so its impact on the change in temperature inside the building is minimal.
Seasonal variations ground temperatures are much lower atmospheric, which allows the establishment of a permanent indoor climate. Heating or cooling of the air inside the cellar is slow due to the low thermal conductivity of the earth.
Classic cellar structure provides heat exchange between its integrated air and ground, part of the floor and walls of the room. Effect of temperature of the atmosphere is eliminated using a heater
If necessary, you can use air to change the temperature. Given that the building is underground, to cool the cellar in winter quite natural air movement, while in the summer time to encourage air flow better with the work fans.
Solution of the problem of excessive amounts of moisture
The most frequent problem cellar microclimate is an excessive amount of moisture. Its evaporation using solar radiation or wind action is impossible, so ventilation is the main way of drainage facilities buried in the ground.
Methods for the ingress of moisture can be divided into three types:
- Moisture can get into the cellar of water through the wall, floor or ceiling in the absence or tackle waterproofing layer. This occurs most often in the spring when the snow melts.
- Internal source of moisture may be items or products that are in the room. Vegetables and fruits, especially in the initial stage of the storage process, evaporation was isolated. Also humidification occurs during the fermentation process, when breathing bees, if used as a cellar omshanika and in many other cases.
- In the spring and autumn period of time when the temperature is much lower in the cellar street, it is a source of moisture condensation. Therefore, the correct use of ventilation, knowledge of the physical laws of condensation and evaporation.
The process of removing moisture by ventilation takes place slowly. Therefore, before beginning this procedure is necessary to determine the cause of increasing humidity cellars and eliminate it as far as possible.
Evaporation of moisture at ventilation is slow, so if you do not eliminate the cause of the water in the cellar, the drying procedure will have no effect
Lowering the concentration of hazardous gases
Another reason for ventilation is a need to change the chemical composition of the air. Thus as a result of storage of agricultural products is an allocation of all possible odors, and at its decay, and also when the content of the bees in the cellar or fermentation tanks abundantly released carbon dioxide, replacing oxygen.
In poorly ventilated cellars possible flatulence different nature of origin. Excessive concentration of carbon dioxide (CO2), Methane, carbon monoxide (CO) or hydrogen sulfide can cause a person anoxia, asphyxia and as a consequence, loss of consciousness. In case of refusal immediate relief, possible fatal outcome.
In the absence of the air circulating concentration of hazardous heavy gases occurs at the bottom cellar. Therefore, if for removing foreign odors sufficiently simple ventilation, for reducing the concentration of gases, whose specific weight the atmospheric air is greater than one, it is necessary ventilation to the location of the air inlet a short distance from floor.
In the case of the prerequisites for the excessive concentration in the cellar heavy gas, it is necessary either to carry out mandatory airing premises before his visit or use sensors or analyzers to determine whether ventilation.
Alcoholic fermentation process leads to an active carbon dioxide gas. Because of the need to maintain a constant ambient temperature is often placed in the fermentation vessel cellars. In the absence of proper ventilation sometimes it leads to suffocation cellar owners
Theoretical Foundations of moisture removal
In that case, if the main purpose of ventilation is a drying room, then from the standpoint of physics problem can be formulated as follows: manner: it is necessary to perform a cellar ventilation device according to this scheme to absolute mass coming into leaving fewer moisture it was out.
Physical Description The processes of condensation and evaporation
There are three basic terms, the essence of which is necessary to understand to understand the nature of condensation and evaporation of moisture from the air:
- The absolute humidity shows a mass of water vapor contained in one cubic meter of air. This value is expressed in g / cu.m.
- Relative humidity is the ratio of current mass of water vapor to the maximum possible, at constant pressure and temperature. Expressed as a percentage.
- Dew point temperature indicates a temperature value is lowered to which water vapor contained in the air reaches saturation and starts the condensation process.
As applied to the cellar, a condensation process can be described as follows. At a certain temperature air has a certain absolute value and relative humidity.
By lowering the temperature value of the absolute humidity remains constant, but the relative - grows. Upon reaching the relative humidity value of 100% occurs dew point and starts discharge of moisture in the form of condensate.
The lower the temperature, the minimal amount of moisture it is capable of retaining in suspension at full saturation
The evaporation process is as follows: when contacting air, which has a relative humidity less than 100%, with it is saturated with moisture, which can last up to a relative humidity value 100%. The higher the temperature, the more moisture it can absorb during the evaporation process.
Drainage of underground rooms in the summer
In dry and hot weather, there is a temptation to open on time damp cellar and start to warm, dry air to remove condensation. This is one of the most common mistakes that lead to the opposite effect - the ingress of moisture from the atmosphere into the dungeon.
For example, at day indication and anticyclone air temperature 32 degrees Celsius and 40% relative humidity there is a feeling air dryness. The cellar at a temperature 12 degrees and relative humidity of 100% is present damp feeling. However, the absolute humidity in the street at such parameters will be bigger than the room.
When ingested, the warm air will begin to cool. the dew point temperature of the outside air above parameters will be equal to 16 degrees. Therefore, during the temperature decrease from 16 degrees to 12 condensation will occur, and the relative humidity will be 100%.
Besides the fact that the humidity in the cellar remains at the same maximum level, there will be an additional flow of water due to condensation
draining underground rooms through ventilation the right to produce for a long time. The volume of air passing through the space should provide minimum incidence figures temperature, to it at low relative humidity occurred process evaporation.
However, after the end of the ventilation due to heat exchange with the walls and floor occurs gradual lowering of the temperature and the condensation water in the air.
Therefore, the temporary removal of moisture from the use of ventilation in the following cases in the warm season:
- amount of moisture in the cellar clearly exceeds the volume which would be there after condensation of water from atmospheric air;
- you need to create conditions for a cessation of intensive processes of decay, the spread of mold and mildew;
- necessary to antifungal treatment which is most effective when applying an antiseptic to dry the surface.
Removing condensate from the cellar in the warm season is performed by alternative methods. Can be used to collect moisture using compounds having good hygroscopic (water absorbent) properties, such as ash or sawdust.
In this case, as far as possible it is necessary to exclude the external air circulation, if not inconsistent with respect for the other parameters of the microclimate premises.
condensate drops from the ceiling, the easiest way to gather with a dry cloth. Summer is the most effective way to deal with dampness in the cellar
Moisture freezing in winter
At low temperatures small absolute air humidity. Therefore, the most effective method for removing moisture by ventilation, which is not quite right is called "freeze" is to ensure the frosty air inflow into the cellar.
Thus, even if a temperature of -10 degrees Celsius air has the highest possible humidity (2.36g / m) after heating it up to room values +5 degrees, the relative humidity becomes equal to the total 30%. One cubic meter of the air will be able to evaporate 4.5 gram of water in the cellar.
Since almost any cellars undesirable temperature reduction to negative values, the flow of freezing air should be carried out in small portions.
It displaces the humid air from the room and mixed with the remaining. Then it is necessary to wait for the temperature increase to normal values and can carry out the procedure again.
When draining the cellar with the help of cold air is important to avoid lowering the temperature below zero for a long time. Exposure to cold on vegetables are less detrimental than excessive moisture
This method is effectively applied in the fall after harvest bookmarks, opening the ventilation at some time during the night.
Technical moments ventilation device
Technically correct implementation of the ventilation system for the cellar along with an understanding of the rules of its use will provide the desired indoor climate. For smaller installations to perform all the work you can own, possessing basic skills in the field of construction.
The system design of ventilation of basements and cellars - a mandatory component of the project documentation home
With insufficient air exchange allowed the formation of additional air vents, installation and construction of duct fans
In the case of setting the air blower in the supply opening, polluted exhaust and spontaneously discharged through exhaust ducts
If the fan is installed on the exhaust duct, air intake is performed naturally. The mass of air in the street without coercion tends to take the place vacated by fan
ventilation device under construction
Drilling of additional air vents
Fan for supply holes
The fan on the exhaust pipe
Acquainted with the peculiarities of calculation of the ventilation system for the various types of accommodations you can read Featured article.
Placing ducts and their servicing
As the ducts typically use plastic or metal pipes. To make demands on plastic resistance to low temperatures. This is to avoid breakage in the winter and the mechanical forces, such as cleaning of kurzhaka.
Usually for the purpose of ventilation underground facilities using two tubes, one of which operates at the air intake, and the second - on the hood. Application of a single pipe leading to a much smaller volume of circulating air.
desirable exit site pipes positioned at different ends of the cellar. In this case, there is a uniform ventilation of the entire floor space, without the formation of air stagnation zones.
The ventilation channels device uses steel, asbestos and polymeric tubes. Currently, in the arrangement of cellars leading plastic
To assemble the venting system of any complexity release pipe fittings and ventilators
The ducts are fixed by means of brackets and clamps to the ceiling of the basement
Vertically disposed pipes are fixed with clamps, fasteners which are selected depending on the material from which the walls
Vent of metal pipes
Components for assembly of the ventilation system
Methods duct mounting
Installing the exhaust pipe on the wall
Place input ventilation is usually located near the floor space, and the air intake location - close to the ceiling. It is necessary to comply with the physical laws of the natural functioning of the air circulation. An exception is the entry into the chimney placement near the floor for more efficient outflow of hazardous heavy gases.
When placing the outdoor exits near the ground is necessary to monitor the levels of snow as well as the formation of a snowdrift above the level of the pipe can cause cessation of ventilation. The wet air exiting from the room is the cause of kurzhaka in the exhaust pipe, which may reduce the rate of air movement or even cause stopping ventilation.
Scheme air at correct and incorrect placing in terms pipes. In the case of complex geometries cellar may experience the need to use multiple points or inflow exhaust air
Cleaning kurzhaka sometimes presents a challenge because it contained ice or higher density deposits. To simplify the work, the fall pipe can be inserted into the hard metal rod with a diameter of 8-12 mm. When fully closed kurzhakom pipe section, translation and rotation of the rod, you can begin the process of cleaning the hood.
If the exhaust pipe is disposed vertically, under its end, it must be disposed in a cellar put the container, which will get condensation and fragments of snow and ice, crumbling under procleaning pipe.
Potatoes under the exhaust pipe is wet because of condensation falling on it. To avoid this, you must place at the opening of the pipe capacity, in which the water will be collected
Natural and forced air circulation
In most cases, using natural ventilation small underground rooms. In winter, the physics of the air mass circulation process is based on the difference between the density of cold and warm air. To do this, the output from the air-supply pipe is located closer to the floor, and the entrance to the exhaust - from the ceiling.
Duct-sectional area is calculated based on the necessary space for a particular index of air circulation volume and the design speed of its motion through the pipes.
To adjust the ventilation volume of the pipe section is better to use a little higher than the calculated complete with gate valve. It can be installed both on the intake and on the exhaust pipe.
Known since ancient times a method of burning candles beneath the chimney. Hot air rushes up, greatly increasing traction
Natural ventilation does not work in the summer, as well as long removes gases, with a specific gravity greater than that of ordinary air. In this case to create an air pressure construct Forced ventilation type by installing axial fans.
Set and fans can exhaust and supply air pipe, as well as both at once. At high humidity in the cellar not recommend installing a fan on the exhaust pipe due to its rapid possible breakage caused by moisture.
The removal of moisture by condensing zones
There is a way to remove moisture from the cellar winter which does not require tubes and openings for the inflow and outflow of air. It is the formation zones to condensation, followed by removal. This method does not refer to air, and to the circulation because of air between the room and the atmosphere is absent.
Most basic implementation of this method is to use a canopy outside the cellar door ajar. Warm air from the cellar penetrating through a small hole, is cooled in contact with cold canopy, which is condensed as frost and kurzhaka. Cold, dry air back into the room.
Using a circuit with a gentle avoids Laying of air ducts from the cellar out. However, this system is not automatic - you must periodically clean kurzhak
In applying such a method must be periodically remove canopy close the door, knock kurzhak and remove it out. As the canopy necessary to use a thick cloth, able to withstand the weight up to 20 kg adhering snow per 1 square meter of its area.
With the rules and technologies construction of ventilation systems introduce next article.
Conclusions and useful videos on the topic
Video # 1. The problem of condensation of moisture in the summer and methods to fix it:
Video # 2. Assembly and installation of the fan on the chimney:
For optimum performance of the ventilation system must be carefully approach the issue of studying the physical fundamentals of air circulation, as well as its condensation and evaporation. Technological same air device is not complicated and its implementation is possible in-house for small spaces.
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