Ventilation of warehouses and storage areas: standards, requirements, necessary equipment
High-quality warehouse ventilation is necessary to ensure labor safety and optimal storage conditions for products.When arranging a ventilation system, it is necessary to adhere to the established standards for the frequency of air exchange, and select equipment whose parameters meet the regulated requirements.
Before you start designing a utility network, you should study the principles and also find out how to arrange warehouse ventilation, don’t you agree?
We will tell you about the features of organizing natural and forced air exchange, list the requirements for equipment, and also provide standardized microclimate parameters for warehouses for various purposes.
The content of the article:
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 that specifies the requirements for organizing the ventilation of premises for storing products, household equipment, building materials and other products.
Features of natural air exchange
Natural air exchange in a warehouse occurs due to the difference in static pressure of air columns of different temperatures.Cooler outside air enters the room through the supply opening, and indoor air exits through the hood.
In the warm season, the supply openings are located at a level of 0.3 to 1.8 m. In cold times, they are located at a distance from the floor of at least 3 m with a total room height of up to 6 m, and 4 m with a higher room height.
If the height of the warehouse is small, then it is possible to design a lower position of the openings, however, it is necessary to take into account the possibility of it being covered with snow and take measures to prevent such a scenario.
Natural ventilation is practically impossible if incoming air must be treated. Cleaning it from dust through filters, heating or humidifying creates resistance in the supply channel and significantly reduces the flow rate.
With natural ventilation, the main problem is the dependence of the flow rate on environmental parameters. If there is excess air supply, manual or automatic dampers are installed on the openings.
Insufficient air circulation can be partially compensated by installing ventilation deflector. A more effective way is to install forced ventilation.
Using forced ventilation
According to paragraphs. 7.1.3-7.1.4. a ventilation device, the functioning of which requires mechanical stimulation, is installed in the following cases:
- if the necessary microclimate parameters cannot be achieved with natural air circulation;
- if at a certain time of the year there are such temperature and humidity characteristics of the outside air that natural ventilation will not provide the required microclimate in the warehouse;
- in the presence of rooms or their areas without natural ventilation.
Exhaust openings must be located in the most contaminated parts of the warehouse. In the case of a non-zero balance of the volume of transported air, its compensation occurs due to the process of infiltration through the walls and roof of the structure.
The use of forced ventilation leads to the need to purchase and install expensive systems, as well as constant costs for electricity, equipment maintenance and measures aimed at compensating for its wear.
Therefore, combined natural and forced air exchange is often used. The operation of mechanical devices is used to compensate for the difference between the required volume of replaced air and ventilation capabilities.
Uncontrolled air exchange through infiltration
When calculating the parameters of equipment used to create the required microclimate, it is necessary to take into account air infiltration through the perimeter of the warehouse. The presence of leaks in structures leads to uncontrolled inflow and outflow of air.
If there is no need to maintain a certain temperature and humidity, then sometimes you can completely abandon any methods of organizing ventilation in favor of infiltration.
However, if it is necessary to create a certain microclimate, uncontrolled air exchange creates problems.This occurs due to variable environmental parameters and the volume of incoming air.
At sub-zero temperatures, the release of warm flow through cracks contributes to the formation of condensation and ice. This is fraught with gradual destruction of supporting structures, the formation of fungus and mold, an increased risk of short circuit and other problems.
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, with some assumptions, it appears in the calculation of heat loss and modeling of the humidity indicator.
If infiltration in warehouses is undesirable, then it is necessary to eliminate the prerequisites for its occurrence. In addition to the presence of cracks in the walls of the building, there are other reasons leading to unaccounted for air exchange.
On the windward side there is a dynamic pressure of the air mass on the wall of the building and the penetration of air into the room. Therefore, when designing warehouses, it is necessary to take into account the wind rose and not place the building wall perpendicular to the prevailing direction.
An effective solution to the problem can also be the installation of wind barriers.
On the lateral and leeward sides the wind pressure is negative. As a result of the resulting difference, conditions are created for the outflow of air from the room.
To minimize the pressure gradient, it is necessary to adhere to recommendations on the geometric parameters of roofs and eliminate points of separation of the flow boundary layer by installing wind-directing elements.
An internal reason for the occurrence of infiltration may be a difference in the amount of supply and exhaust air. Unbalanced operation of the ventilation system leads to compensation of the missing or excess volume due to infiltration.
Therefore, periodic calibration of fans, cleaning of air ducts and filters, as well as other preventive maintenance are necessary.
Requirements for installed equipment
Ventilation equipment works in conjunction with other devices to create and maintain conditions for the normal functioning and technical condition of the warehouse. Therefore, it is necessary not only to comply with the requirements 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 ventilation equipment must be selected based on the calculated air circulation, taking into account possible volume losses due to incomplete tightness of the system.
In small warehouses, equipment is placed based on the following principles:
- accessibility and convenience of carrying out preventive and repair work;
- compliance with fire and electrical safety requirements;
- availability of free space.
In large warehouses where compliance with regulations is necessary, the equipment is installed in a special room or on the roof of the building. This depends on the classification of the warehouse premises into certain fire hazard categories.
Backup and emergency ventilation systems
If ventilation equipment breaks down and the system stops, an emergency situation may occur in the warehouse. A long-term lack of air exchange can lead to damage to stored products and create conditions for high concentrations of unwanted impurities in the air.
Therefore, the regulatory documents specify the procedure for installing backup systems and their parameters.
According to clause 7.2.8, if permanent presence of people is expected in the warehouse premises, then the air exchange systems must be equipped with backup fans or two or more units must be used.
According to clause 7.2.18, in rooms with a capacity of more than 10 tons and a high fire hazard category, it is necessary to provide a backup system that will fully meet the need for air exchange.
It is also possible for an emergency situation to occur in a warehouse with the release of a large volume of pollutants. Short-term operation of the ventilation system in forced mode will help solve the problem. Demonstrate effective work aspiration systems.
According to clause 7.6.1, air flow and other parameters of the emergency system are determined based on the provisions of the technological part of the project.
Hoods to remove pollutants are placed depending on its density. If the volatile components are heavier than air, then the pipes are installed in the work area, and if they are lighter, then under the ceiling.
Microclimate devices
The most effective way to ensure temperature and humidity conditions is to integrate air heaters and humidifiers into the supply ventilation. In this case, air will be supplied with predetermined parameters.
Heaters can be electric or water type. The latter are more common for ventilation systems of warehouses and large complexes.
During periods of the year with characteristic sub-zero temperatures, it is important to use heat recovery systems. This solution significantly reduces the cost of heating the warehouse premises.
Due to the presence of a separate zone for equipment, when choosing a recuperator or regenerator, you can only be guided by financial costs and system efficiency. The noise level and weight of devices are not as important as when using them in apartment ventilation.
Rotary heat exchangers and water heaters have built-in or external electric motors. According to clause 7.2.7, it is necessary to provide backup motors and pumps for them in case of failure of the main components.
Microclimate parameters for typical warehouses
The microclimate parameters in warehouses and the frequency of air exchange are prescribed in NTP-APK 1.10.17.001-03 “Standards for the technological design of bases and general-purpose warehouses of resource supply enterprises,” 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
Warehouse air exchange is necessary to achieve two goals:
- creation of a special microclimate in the room that is optimal for storing this type of product;
- removal of harmful, explosive and other impurities and aerosols from the premises.
The air exchange rate is calculated using the formula:
K (1/h)=A/V,
Where:
- A – volume of incoming air per hour, (m3/h);
- V – warehouse volume, (m3).
For the storage of most types of products, regulatory documents specify an air exchange rate of one. When the premises are used non-commercially as a warehouse, this figure is often significantly lower. This is justified if ventilation of such power is guaranteed to provide the required temperature and humidity indicators.
For commercial activities, it is necessary to comply with the requirements of regulatory documents on room ventilation.
The total capacity of the installed systems must provide the required air circulation. Otherwise, it is impossible to obtain a positive conclusion from Rospotrebnadzor and the fire inspection on the use of the warehouse for its intended purpose.
If there are several types of products in the warehouse, it is necessary to provide 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 room temperature may be unregulated. The exception includes warehouses with rolled waterproofing bitumen-polymer and polymer materials used in the construction of roofs, foundations and walls of premises with unusually high levels of humidity.
The air temperature in this case should not be lower than +50C.
Humidity in warehouses of this type is not standardized, except for the case of storage of bulk building materials. Cement, graphite and gypsum must not be allowed to become moist or contaminated. The permissible relative humidity during their storage is determined by the manufacturer and depends on the material and the method of its packaging.
Air circulation for sanitary-technical and sanitary-ceramic products is not standardized. For building materials, the required air exchange rate is taken equal to unity.
Features of wood storage
There are no general regulatory documents regulating air parameters in a timber warehouse. The main criteria when choosing ventilation is the humidity permissible for a particular type of material or finished product.
If the specifics of production require the simultaneous supply of a large amount of raw wood, then forced ventilation is necessary, which is used immediately after loading the product. When the material reaches its natural moisture content, mechanical blowing is turned off.
In warehouses with lumber, the microclimate is constantly monitored using special humidity testers.
For uniform ventilation of wood and wood-based products, it is necessary to store them correctly. The order in which round timber and lumber are stacked must be observed.
When transporting small items, a dense packing method is often used to save space.After such products are received at the warehouse, they must be laid out or scattered so that all components have access to air inside the heap.
Otherwise, high humidity of the material will create favorable conditions for the formation of fungus and mold.
Often, a warehouse is equipped with an area for primary wood processing - cutting round timber or filing edges. As a result of these works, wood dust of various sizes is released into the air. Constant inhalation of it is a common non-infectious factor in the development of chronic bronchitis.
If you remove dust using general ventilation, then over time the entire warehouse will be contaminated. Therefore, they provide for the installation of local cyclonic-type chip and dust extractors with a separate exhaust, 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.
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 plumbing tools are stored at a temperature not lower than +5°C and air humidity up to 70%.
For complex equipment, such as woodworking machines, manufacturers provide recommendations on temperature and humidity conditions during their conservation.
It is necessary to strictly adhere to these requirements, because complex units contain elements created using combinations of different materials, the properties of which can change if stored improperly.
Often, metal products and equipment are treated against corrosion directly on the warehouse premises. When performing it, in order to avoid exposure to increased concentrations of toxic fumes, it is necessary to ventilate the room for 1-1.5 days.
In rooms where flammable and explosive substances are stored, additional equipment should be provided smoke ventilation.
Conclusions and useful video on the topic
The video demonstrates the organization of ventilation in a warehouse complex:
Installation device for removing sawdust into a separate hood:
Strict compliance with the requirements of regulatory documents on warehouse ventilation will create the microclimate necessary for high-quality storage of products.
The variety of equipment offered will help to implement almost any system configuration, taking into account the required mode and design features of the building.
Do you have anything to add, or do you have any questions about organizing warehouse ventilation? You can leave comments on the publication and participate in the discussion of the material. The contact form is located in the lower block.
Properly organizing ventilation in a warehouse with vegetables, for example, means preserving the harvest. My parents live in the village and decided to get serious about the agricultural business: growing vegetables and then selling them. There was a storage issue. The warehouse where coal was previously stored was converted.
We started by studying information about how to store vegetables, what needed to be organized and arranged for this. We came to the conclusion that ventilation was necessary, but there was none in the warehouse before. Vegetables require a certain temperature and fresh air to remain edible.
We chose supply type ventilation with natural exhaust. In the first month, they did not take into account that vegetables breathe and emit carbon dioxide. Then they added ducts that push out the recycled air.
We bought a nice warm warehouse and planned to store our equipment there. We didn’t move in right away, but six months later, the warehouse was empty. I saw that black mold was growing on the walls, talked with specialists and they told me that most likely the problem was in the ventilation, or rather in its absence, because what was done did not meet the standards. I had to hire people and redo everything, it cost a pretty penny, but I was also so glad that I got the premises cheaply, these are the pitfalls.