High-quality ventilation of the warehouse is necessary to ensure occupational safety and optimal storage conditions for products. When setting up the ventilation system, it is necessary to adhere to the established norms of the rate of air exchange, and choose equipment, the parameters of which correspond to the regulated requirements.
Before you begin to design the engineering network, you should learn the principles, as well as learn how to arrange warehouse ventilation, do you agree?
We will tell you about the features of the organization of natural and forced air exchange, list the requirements, presented to the equipment, as well as we give the normalized parameters of the microclimate for warehouses of different destination.
The content of the article:
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Basic principles of warehouse ventilation
- Features of natural ventilation
- Use forced ventilation
- Uncontrolled air exchange through infiltration
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Requirements for installed equipment
- Basic rules for equipment placement
- Redundant and emergency ventilation systems
- Devices for microclimate
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Microclimate parameters for typical warehouses
- The concept of air exchange rate
- Storage of building materials and products
- Wood storage features
- Storage of metal and equipment
- Conclusions and useful video on the topic
Basic principles of warehouse ventilation
Code of Rules SP 60.13330.2012 “SNiP 41-01-2003. Heating, ventilation and air conditioning ”is the main document, which sets out the requirements for organizing the ventilation of premises for storing products used in household equipment, building materials and other products.
Features of natural ventilation
Natural air exchange of the warehouse occurs due to the difference in static pressure of different temperature air columns. The colder outside air enters the room through the air inlet, and the internal air comes out through the hood.
During the warm period, the air inlets are located at a level of from 0.3 to 1.8 m. In the cold season arrange at a distance from the floor of at least 3 m with a total height of the room up to 6 m, and 4 m with a higher height premises.
If the height of the warehouse is small, then you can design a lower position of the holes, but you need to consider the possibility of sweeping it with snow and take measures to prevent such a scenario.
Natural ventilation is almost impossible when it is necessary to treat the incoming air. Cleaning it from dust through filters, heating or moistening create resistance in the supply channel and significantly reduce the flow rate.
With natural ventilation, the main problem is the dependence of the flow rate on the parameters of the environment. In the event of excessive air inflow to the openings, the dampers are mounted of manual or automatic type of action.
Insufficient air circulation can be partially compensated by setting vent deflector. A more effective way - the installation of forced ventilation.
With natural ventilation, exhaust vents on the roof of the warehouse building are installed in such a way as to obtain the maximum possible traction
Use forced ventilation
According to paragraphs. 7.1.3-7.1.4. a ventilation device, for the operation of which mechanical stimulation is necessary, is installed in the following cases:
- if the necessary parameters of the microclimate can not be achieved with natural air circulation;
- if at certain times of the year there are such temperature and humidity characteristics of the outside air that natural ventilation does not provide the required microclimate indicators in the warehouse;
- in the presence of premises or their zones without natural ventilation.
Placement of exhaust openings must be carried out in the most polluted parts of the warehouse. In the case of a non-zero balance of the volume of air transported, its compensation occurs through the process of infiltration through the walls and roof of the structure.
Usually colder fresh air spreads to the bottom of the room, displacing polluted to the top. In this case, the exhaust holes are placed under the ceiling of the warehouse.
The use of forced ventilation leads to the need to purchase and install expensive systems, as well as fixed costs for electricity, equipment maintenance and measures aimed at compensating its wear and tear.
Therefore, often used joint natural and forced ventilation. The operation of mechanical devices is used to compensate for the difference between the required volume of replaced air and the possibilities of ventilation.
Uncontrolled air exchange through infiltration
When calculating the parameters of the equipment that is used to create the desired microclimate, it is necessary to take into account the infiltration of air through the perimeter of the warehouse. The presence of leaks in the construction leads to uncontrolled inflow and outflow of air.
If the observance of a certain temperature and humidity is not necessary, then sometimes it is possible to completely abandon any means of organizing ventilation in favor of infiltration.
However, if it is necessary to create a certain microclimate, uncontrolled air exchange creates problems. This is due to the non-constant parameters of the external environment and the volume of incoming air.
At sub-zero temperatures, the exit of a warm stream through the gaps promotes the formation of condensate and ice. This is fraught with the gradual destruction of load-bearing structures, the formation of mold and mildew, an increase in the risk of short circuits and other problems.
Heat loss of any building is easy to identify using infrared shooting. In this way, it is possible to identify places of intensive infiltration and take measures to eliminate it.
Since the volume of infiltration is not constant and depends on many parameters, it is not taken into account in the standard calculation of air exchange. However, it is with some assumptions that appears in the calculation of heat loss and modeling of the humidity index.
If infiltration in warehouses is undesirable, then it is necessary to eliminate the causes of its occurrence. In addition to the presence of cracks in the walls of the building there are other reasons leading to unrecorded air exchange.
On the windward side, there is a dynamic pressure of air mass on the wall of the building and air penetration into the room. Therefore, when designing warehouses, it is necessary to take into account the wind rose and not have the wall of the building perpendicular to the prevailing direction.
An effective solution to the problem can also be the installation of anti-wind barriers.
On the side and leeward sides, the wind pressure is negative. As a result of the resulting differential conditions are created for the outflow of air from the room.
To minimize the pressure gradient, it is necessary to adhere to the recommendations on geometric parameters. roofs and the elimination of separation points of the boundary layer of flow with the help of the installation of wind guide elements.
The internal reason for the occurrence of infiltration may be the difference in the amount of supply and exhaust air. Unbalanced operation of the ventilation system leads to compensation for the missing or excess volume due to infiltration.
Therefore, periodic calibration of the fans, cleaning of air ducts and filters, as well as other preventive maintenance are necessary.
A dirty ventilation filter is the most common cause of reduced system performance. Most of them are easy to clean, which requires minimal time
Requirements for installed equipment
Ventilation equipment works in conjunction with other devices to create and maintain conditions for normal functioning and technical condition of the warehouse. Therefore, it is necessary not only to comply with the provisions specified in SP 60.13330.2012, but also to take into account the provisions of other regulatory documents.
Basic rules for equipment placement
The power of the ventilation equipment must be selected on the basis of the calculated air circulation taking into account possible volume losses due to incomplete tightness of the system.
In small warehouses the equipment is placed on the basis of the following principles:
- availability and ease of maintenance and repair;
- compliance with fire and electrical safety requirements;
- availability of free space.
In large warehouses where compliance with standards is necessary, equipment is installed in a special room or on the roof of a building. It depends on the classification of the warehouse premises to certain categories of fire hazard.
If the ventilation equipment is installed on the roof of the building, then it is necessary to restrict access to it by unauthorized persons. This requirement is spelled out in SP 60.13330.2012
Redundant and emergency ventilation systems
In case of breakdown of ventilation equipment and system shutdown, an emergency situation in the warehouse may occur. Prolonged absence of air exchange can lead to deterioration of stored products and to the creation of conditions for a high concentration of undesirable impurities in the air.
Therefore, in the regulatory documents prescribed order of installation of backup systems and their parameters.
According to paragraph 7.2.8, if in the premises of the warehouse people are expected to stay permanently, then air exchange systems must be equipped with backup fans or use two or more installations.
According to paragraph 7.2.18 in rooms with a capacity of more than 10 tons and a high fire risk category, it is necessary to provide a backup system that will fully meet the need for air exchange.
An emergency situation with the release of a large amount of pollutants is also possible in the warehouse. The short-term operation of the ventilation system in the forced mode will help solve the problem. Effective work demonstrate aspiration systems.
According to paragraph 7.6.1 air consumption and other parameters of the emergency system are determined based on the provisions of the technological part of the project.
Hoods to remove pollutant is placed depending on its density. If the volatile components are heavier than air, then the nozzles are installed in the working area, and if it is lighter, then under the ceiling.
Dust suspension not only adversely affects human health. Flour and wood dust is explosive, so the installation and operation of emergency ventilation must be checked by the fire inspectorate.
Devices for microclimate
The most effective way to ensure the temperature and humidity conditions is the integration of heaters and humidifiers into the ventilation. In this case, the air will be supplied with predetermined parameters.
Heaters can be electric and water type. The latter are more common for ventilation systems of warehouses and large complexes.
In the period of the year with characteristic negative temperatures, the use of heat recovery systems. This solution significantly reduces the cost of heating the warehouse.
Due to the presence of a separate equipment zone, the choice of a heat exchanger or a regenerator can be guided only by financial costs and system efficiency. The noise level and the mass of the devices are not as important as when using them in apartment ventilation.
Rotor recuperators and water heaters have built-in or external electric motors. According to paragraph 7.2.7 for them it is necessary to provide backup motors and pumps in case of failure of the main components.
The rotor heat exchanger makes noise, however for a warehouse it is not so important as high efficiency. Therefore, the use of this type of device is a popular solution for non-residential ventilation.
Microclimate parameters for typical warehouses
The parameters of the microclimate in warehouses and the frequency of air exchange are prescribed in the NTP-APK 1.10.17.001-03 “Norms technological design of bases and warehouses of general-purpose enterprises for resource provision ”, as well as in industry documents.
For example, the air parameters of a food warehouse depend on the storage conditions and the range of specific products.
The concept of air exchange rate
Air exchange warehouse is necessary to achieve two goals:
- the creation of a special microclimate room optimal for the storage of this type of product;
- removal from the premises of harmful, explosive and other impurities and aerosols.
The calculation of the frequency of air is performed according to the formula:
K (1 / h) = A / V,
Where:
- A - the volume of incoming air in one hour, (m3/ h);
- V - warehouse capacity, (m3).
For storing most types of products, the air exchange rate is set to one in regulatory documents. When non-commercial use of the premises as a warehouse is often this figure is significantly lower. This is justified if the ventilation of such power is guaranteed to provide the necessary indicators of temperature and humidity.
In commercial activities, it is necessary to comply with the requirements of regulatory documents for ventilation of the room.
The total capacity of the installed systems should provide air circulation of the required multiplicity. Otherwise, it is impossible to obtain a positive opinion from Rospotrebnadzor and the fire inspectorate on the use of the warehouse for its intended purpose.
Checking for compliance of ventilation parameters with regulatory requirements is the responsibility of the fire inspector. If violations are detected, the warehouse can be suspended until they are rectified.
If there are several types of products in stock, it is necessary to ensure the microclimate parameters that satisfy the storage conditions of each of them.
Storage of building materials and products
When storing most types of building materials, the temperature regime of the room may be unregulated. Warehouses with roll-over waterproofing asphalt-polymer and polymer under the exception materials used in the arrangement of roofs, foundations and walls of rooms with non-standard high humidity level.
The value of air temperature in this case should not be below +50C.
Humidity in warehouses of this type is not standardized, except in the case of storage of bulk building materials. Moisturizing and contamination of cement, graphite and gypsum must not be allowed. The permissible relative humidity during storage is determined by the manufacturer and depends on the material and the method of its packing.
Air circulation for sanitary and sanitary-ceramic products is not standardized. For building materials, the required air exchange rate is taken equal to unity.
Wood storage features
There are no general regulatory documents regulating the indicators of air in the timber stock. The main criteria for choosing ventilation is the humidity allowed for a particular type of material or finished product.
If the specifics of production implies a one-time receipt of a large amount of raw wood, then you must have forced ventilation, which is used immediately after loading products. When the material reaches the natural moisture index, the mechanical purge is turned off.
In the warehouse with lumber constantly monitor the microclimate, using special moisture testers.
For uniform ventilation of wood and products based on it, their proper storage is necessary. You need to follow the procedure for laying roundwood and lumber in piles.
Without the correct erection of the stacks it is impossible to dry the wood to the required performance. Air must penetrate inside the array, otherwise the tree will rot with any ventilation.
When transporting small products often use the method of dense packing with space saving. After receiving such products at the warehouse, it must be decomposed or scattered so that all components have air access inside the heap.
Otherwise, at high humidity of the material favorable conditions for the formation of fungus and mold will arise.
Often, a warehouse is equipped with a zone for the primary processing of wood - sawing roundwood or sawing edges. As a result of this work, wood dust of various size is released into the air. Its constant inhalation is a common non-infectious factor in the onset of chronic bronchitis.
If dust is removed using general ventilation, the entire warehouse will be contaminated over time. Therefore, it is envisaged to install local blasting and dust extraction systems of a cyclonic type with a separate hood, if such devices are not included in the set of woodworking equipment.
Storage of metal and equipment
For metal products, such as pipes, taps, valves, temperature and humidity indicators are not standardized.
Color and black metal is not picky about temperature and humidity. Ventilation is necessary to ensure safe working conditions.
Electrical equipment and spare parts for internal combustion engines must be stored in compliance with anti-corrosion conditions.
Hand-held power tools, metal-cutting and metalworking tools are stored at a temperature not lower than + 5 ° С and air humidity is up to 70%.
For complex equipment, such as woodworking machines, manufacturers give recommendations on the temperature and humidity conditions during their conservation.
It is necessary to strictly adhere to these requirements, because complex aggregates contain elements created by with the use of combinations of different materials, the properties of which may change if improperly storage.
Often, the processing of metal products and equipment against corrosion is carried out directly in the warehouse. When performing it to avoid exposure to increased concentrations of toxic fumes, it is necessary to ventilate the room for 1-1.5 days.
In the rooms where flammable and explosive substances are stored, it should additionally be arranged anti-smoke ventilation.
Conclusions and useful video on the topic
The video demonstrates the organization of ventilation of the warehouse complex:
Installation device for removing sawdust in a separate hood:
Accurate observance of the requirements of regulatory documents on the ventilation of the warehouse will allow you to create a microclimate necessary for high-quality storage of products.
The variety of the proposed equipment will help to implement almost any system configuration, taking into account the required mode and design features of the building.
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