The use of dehumidifiers in static and dynamic storage systems plays a critical role in preserving the integrity and longevity of stored items. In dynamic storage, where frequent access and use occur, humidity levels must be continuously monitored and recorded; this aims to prevent fluctuations that may arise from intensive use of stored items and environmental interactions. On the other hand, in static storage, which typically involves long-term preservation and rarely accessed items, maintaining constant and controlled humidity levels is essential. Humidity control and the use of dehumidifiers ensure the protection of sensitive materials, such as historical documents or artworks, against the risks of deterioration or damage caused by moisture reactions. In both cases, humidity control and dehumidifier usage play a vital role in protecting stored items by preventing issues such as mold formation, material degradation, and structural damage. For this reason, special attention must be given to humidity control in the design and management of static and dynamic storage areas, and expert teams with experience in static/dynamic storage conditions should be consulted for dehumidifier selection.
What is Static Storage?
Static storage is a storage method used particularly for sensitive items that require protection. This method is suitable for situations where frequent access is not needed, and storage areas with the following characteristics are generally referred to as static storage. This concept is used to distinguish between systems with large and continuously variable loads and systems with no variable loads. For example, considering a document archive, if no one is working in the room, this is regarded as a relatively "static" storage application. In contrast, cold storage facilities where forklifts move products in and out throughout the day, along with cold corridors connected to truck loading docks, are classified as "dynamic" because they create large and variable heat and humidity loads.
Temperature and Humidity Control: Static storage areas are generally maintained at constant temperature and humidity levels to prevent material deterioration. Optimal temperature settings may vary depending on the type of objects being stored. Generally, it is preferred to keep the temperature within a stable and predictable range. Temperature fluctuations can cause materials to expand or contract, leading to permanent structural damage. For this reason, temperature and humidity control is of great importance in static storage. Static storage areas tend to be the simplest humidity control applications. Loads are constant and tolerances are wide. Unless the storage area is very large, complex centralized humidity control air handling units are generally not beneficial. System design typically involves placing a dehumidifier sized appropriately for the stored area, drawing reactivation air from outside and directing it back outside, and positioning the dehumidifier to ensure effective air circulation. Examples of static storage include archive rooms or repositories where rare historical documents are preserved. In a static storage area designed in this manner, maintaining humidity and temperature within tolerances and ensuring that the materials inside remain undamaged for many years is extremely important. High temperature or humidity directly affects the lifespan of products. It is known that archival documents and rare artifacts preserved in static storage become brittle and fragile at very low temperature and very low humidity values. On the other hand, at high temperature and high humidity levels, the organic inks on the artifacts/documents fade and mold formation occurs on the documents. The table below provides some static storage examples and the relative humidity values at which the storage should be maintained.
Regular maintenance and monitoring are performed to preserve the condition of stored materials and to check for any signs of deterioration. Static storage ensures that items requiring protection are kept in a safe and stable environment for extended periods, making it possible to pass on materials of historical, cultural, or scientific significance to future generations. Before selecting dehumidifiers to be used in static storage, the storage temperature and humidity conditions must be considered. From the graph below, information can be obtained about which operating principle the dehumidifier should have and which dehumidifier will operate more efficiently based on the required storage conditions.
NKT – Humidity Control Technologies offers optimum solutions for static storage in terms of energy consumption, initial investment, and operating costs under constant humidity loads, using condensation-type mechanical dehumidifiers and silica gel rotor chemical dehumidifiers.
Silikajel Rotorlu Kimyasal Nem Alma Üniteleri
Yoğuşmalı Tip Mekanik Nem Alma Üniteleri
What is Dynamic Storage?
Active storage refers to storage areas that are typically exposed to variable temperature and humidity loads and exhibit intensive activity. In addition to the temperature and humidity load contained within the specific control volume, such storage areas may be exposed to continuously variable loads such as open doors, conveyor openings, variable personnel loads, variable fresh air loads, moisture from products, washed areas, and wet surfaces. Taking these values into account when designing humidity control systems prevents humidity and temperature fluctuations under dynamic storage conditions. In conditions where humidity control tolerance is not critical, precise control of the air with additional automation systems and dampers may not be necessary. When designing the system, the process tolerance values must be thoroughly analyzed to maintain cost balance and avoid incorporating excessive control equipment. For example, in a gummy candy resting room, temperature and humidity fluctuations within a +/-5 tolerance remain within the system's reference values, while in a lithium storage system, tolerance values exceeding +/-2 can trigger chemical reactions. Below is a graphical representation of temperature and humidity variability in a dynamic storage environment under variable humidity loads.
Incorrect design or undersized selection of the dehumidifier or the units providing temperature within the dynamic storage will cause indoor air conditions to fluctuate against variable loads. For example, in a cold room where doors are constantly opened and closed and the dehumidifier designer has not included the moisture load from door openings in the calculations, moisture transfer toward the control volume due to partial vapor pressure differences is inevitable each time a door opens. In this case, the indoor humidity value will rise, and the dehumidifier will activate to try to restore the humidity balance. The cycle will repeat with each door opening, and thus the humidity and temperature fluctuations within the room will continue.
Engineers must take variable humidity loads into account during the design phase of dynamic storage systems. This requires that the capacities of existing dehumidifiers be appropriately adjusted considering variable loads. With such an approach, the additional moisture load introduced to the dynamic storage environment is effectively removed by the dehumidifiers. This process prevents the specified air conditions within the room from exceeding the defined tolerance values and ensures a stable environment is maintained.
Cold or frozen storage facilities, which also fall under the static room category, should also be evaluated according to dynamic storage conditions when the variable load parameter is included. Dehumidifier selection is extremely important, particularly in cold corridors integrated with cold storage and truck loading ramps. The image below illustrates an example cold room from dynamic storage systems and the challenges encountered in these environments.
In a cold corridor consisting of 4 loading ramps open to the atmosphere where the loading corridor is at 15°C, and cold rooms at 4°C with open doors, humidity problems can lead to a series of negative consequences for both the stored materials and the storage environment. If the dehumidifier was selected without considering the varying atmospheric conditions and other parameters during the design phase, food products may spoil due to high humidity levels, lose quality, or experience issues such as mold growth. Electronic goods, pharmaceuticals, and other sensitive products can be affected by corrosion, mold, or other damage caused by moisture. Continuously rising and falling humidity levels cause cooling and dehumidification systems to operate with higher energy consumption. This leads to decreased energy efficiency and increased operating costs. Moisture can cause frost formation on the interior surfaces of cold rooms, on evaporator surfaces, above door entrances, and on products. Additionally, condensation can cause water puddles and icy floors due to frost formation, posing a safety risk for workers.
NKT – Humidity Control Technologies offers optimum solutions for dynamic storage using silica gel rotor chemical dehumidifiers in terms of energy consumption, initial investment, and operating costs under constant humidity loads.
Silikajel Rotorlu Kimyasal Nem Alma Üniteleri
In this comprehensive review, the importance of humidity control in static and dynamic storage environments and the unique challenges of these two different storage types have been examined. While static storage requires long-term and stable humidity control, dynamic storage requires rapid and effective response to continuously changing humidity loads. In both cases, proper humidity control is of vital importance for preserving the quality of stored products and optimizing operating costs. As NKT – Humidity Control Technologies, with our expert engineering team, we offer our customers the most suitable humidity control solutions, providing energy-efficient, high-performance recommendations to increase the efficiency of storage areas and protect the integrity of stored items.