The problems encountered in the use of cold storage mainly revolve around six aspects: refrigeration system failures, insulation and sealing failures, electrical control issues, improper storage of goods, safety risks, and poor operational management. These issues are often interrelated, for example, equipment failures can cause fluctuations in warehouse temperature, leading to cargo loss and increased energy consumption.

Refrigeration System: The “Heart” Problem of Cold Storage

The refrigeration system is the most critical component of a cold storage, and the problems are also the most concentrated.

Poor or no cooling effect: This is the most common problem. Possible reasons may include:

Refrigerant leakage: Insufficient refrigerant in the system leads to a decrease in cooling capacity.

Compressor failure: The efficiency of the compressor decreases, usually caused by component wear due to prolonged use.

Excessive frosting on the evaporator: A thick frost layer can seriously hinder heat exchange and affect the cooling effect.

Poor heat dissipation of condenser: Dust and dirt accumulate on the surface of the condenser, leading to a decrease in heat dissipation efficiency and even causing high-pressure protection shutdown.

Expansion valve malfunction: Damaged temperature sensing bulb, ice blockage or dirty blockage may cause abnormal refrigerant flow, or even complete closure.

Large fluctuations in storage temperature: Unstable temperature may accelerate the deterioration of goods. The main reasons are:

Excessive temperature difference between inside and outside: frequent opening and closing of the storage door or inadequate sealing of the storage door can cause loss of cold air and invasion of hot air.

Improper defrosting control: Excessive or prolonged defrosting can cause temperature rise.

Improper setting of equipment parameters: Improper setting of parameters such as temperature controller and pressure controller may lead to frequent start and stop of the compressor.

Sensor malfunction: The temperature and humidity sensor is malfunctioning, providing incorrect data, resulting in a system misjudgment.

Other system malfunctions:

The phenomenon of “running cold”: the insulation layer of the refrigeration pipeline or storage body is damaged, resulting in ineffective loss of cooling capacity.

There is air in the system: Air mixed into the refrigeration system can cause abnormal increases in exhaust pressure and temperature, reducing refrigeration efficiency.

Pipeline blockage: Components such as filters and expansion valves in the system are blocked by dirt, affecting the circulation of refrigerant.

Insulation and sealing: The “cotton coat” in the cold storage is damaged

Failure of insulation material: The gaps, seams, or insulation layer of the warehouse board or pipeline are damaged, resulting in loss of cooling capacity, prolonged high load operation of the refrigeration unit, and increased energy consumption.

Poor sealing of the warehouse door: The aging, damage, or improper installation of the sealing strip of the warehouse door can lead to cold air leakage and external hot air intrusion, directly affecting the temperature stability and energy consumption of the warehouse.

Floor issue: For low-temperature cold storage, if the anti freezing system under the floor fails, it may cause the floor to bulge and crack, affecting structural safety and operations inside the warehouse.

Electrical and Control Systems: The ‘Brain’ of Cold Storage Failed

Power failure: The dedicated circuit breaker tripped, the power supply line aged or had poor contact, causing the cold storage to suddenly shut down.

Thermostat malfunction: The display screen is not displaying, the buttons are malfunctioning, or the temperature probe is damaged, resulting in the inability to accurately control the temperature of the warehouse.

Communication interruption: In ultra-low temperature environments (such as -30 ℃), IoT modules used for monitoring may experience communication packet loss, leading to remote monitoring failure.

Lighting system malfunction: The lighting fixtures in the warehouse are not explosion-proof, have poor moisture resistance, or have short circuits, which may cause electrical fires.

Storage of goods: improper management is the ‘culprit’

Unreasonable stacking:

Impact on airflow circulation: If goods are stacked too tightly or directly against walls, it will hinder the circulation of cold air, causing local “hotspots” and accelerating the deterioration of goods.

Exceeding storage capacity: Excessive purchase volume and exceeding the design load of the cold storage, resulting in prolonged inability to lower the storage temperature.

Improper temperature and humidity control:

Temperature fluctuations: Even small temperature fluctuations can have a serious impact on sensitive goods such as fresh produce and medicine. Research has shown that for every 1 ℃ increase in error during temperature zone switching, the loss rate may increase by 17%.

Excessive humidity: Excessive humidity can easily cause condensation and mold on the surface of goods; If the humidity is too low, it may cause the goods to dry up (lose water).

Problems with the goods themselves: There are potential issues with the goods before they are stored, such as insufficient pre cooling or beginning to deteriorate, which can quickly deteriorate after storage and potentially affect surrounding goods.

Goods loss: Due to the above reasons, fruits, vegetables, meat, medicines, etc. may experience mold growth, frostbite, dry wear and other losses, leading to storage disputes and economic losses.

Security risk: an undeniable ‘time bomb’

Fire:

Thermal insulation materials are flammable: polyurethane foam and other thermal insulation materials used in some cold storages burn fast and release a large amount of toxic smoke.

Hidden dangers in electrical circuits: unauthorized connections, aging circuits, short circuits, etc. are common causes of fires.

Violation of hot work regulations: During the renovation or maintenance of cold storage facilities, unlicensed welding, gas cutting, and other illegal hot work operations can easily ignite insulation materials.

Ammonia explosion: For cold storage in ammonia refrigeration systems, once ammonia leaks and reaches the explosive limit (15.4% -28% volume concentration in air), it can explode when exposed to open flames or electric sparks.

Ammonia gas leakage:

Toxic hazards: Ammonia has strong irritants, and short-term exposure to high concentrations of ammonia can cause suffocation or even death.

Equipment corrosion: Ammonia has strong corrosiveness to copper and copper alloys, and the presence of water in the system can exacerbate pipeline corrosion and increase the risk of leakage.

Personnel suffocation:

Fire smoke: The large amount of toxic smoke such as carbon monoxide produced by a fire can easily cause poisoning and suffocation of personnel in a confined space.

Refrigerant leakage: In a sealed cold storage, if a large amount of refrigerant (especially Freon) leaks, it will replace oxygen in the air, causing personnel to suffer from hypoxia and suffocation.

Other security risks: personnel trapped due to locked warehouse doors; The ground is frozen and slippery, causing falls and injuries; Collapse of shelves, etc.

Improper management and maintenance:

Low inspection efficiency: relying on manual regular inspections, which is time-consuming, costly, and has problems such as inaccurate data recording and delayed discovery of hidden dangers.

Lack of maintenance records: Lack of systematic and standardized maintenance plans and records, resulting in equipment problems that cannot be traced and prevented.

Inexperienced personnel operation: Operators who are not familiar with the equipment, have incorrect parameter settings, or mishandle alarms may cause bigger problems.

Other issues

Ice formation inside the warehouse: Poor drainage system, incomplete defrosting, or poorly sealed warehouse doors can all cause ice formation on the floor, walls, or below the evaporator, affecting operations and posing safety hazards.

Odor generation: Mixing different goods, failure to clean corrupt goods in a timely manner, or inadequate cleaning and disinfection can lead to odor generation in the warehouse, affecting the quality of other goods.

Excessive noise: Compressors, fans, and other equipment may produce abnormal noise during operation due to aging, looseness, or improper installation, affecting the surrounding environment.

Summary

The smooth operation of cold storage is a systematic project. Negligence in any link, whether it is hardware failure or management vulnerability, can trigger a chain reaction, causing economic losses and even security accidents.

Instead of passively responding to problems after they arise, it’s better to focus on proactive prevention:

Establishing a regular maintenance system is the core of ensuring equipment health and extending the lifespan of cold storage.

Introducing an intelligent monitoring system can achieve 24-hour online monitoring and early warning, effectively improving management efficiency and security.

Developing and practicing emergency plans can ensure that personnel can respond correctly in case of emergencies such as leaks and fires, minimizing losses to the greatest extent possible

Cold storage essence: It is a building or equipment that can be artificially cooled.

Function: Create a suitable low temperature and high humidity environment for storing items through cooling facilities.

Purpose: It is a place for processing and storing perishable goods such as agricultural and livestock products, food, and medicine, which can escape the influence of climate, effectively extend their shelf life, and regulate market supply.

A complete cold storage, regardless of size, is a highly integrated system. It is not just the visible ‘cold room’, but is composed of multiple core systems working together.

We can break down the components of the cold storage into the following four core systems:

This is the “body” and “shell” of the cold storage, mainly used for insulation and isolation from external humid and hot air.

Cold Storage body:

Function: The walls, ceilings, and floors that make up the cold storage prevent the loss of cooling capacity.

Material: Both sides are usually made of color steel plate or stainless steel plate, and the middle layer is made of insulation material.

Core insulation material:

Polyurethane: currently the mainstream choice, with the best insulation performance, but slightly higher price.

Polystyrene: Its insulation performance is slightly inferior, but it is cheap and suitable for room temperature warehouses with low requirements.

Extruded board: usually used for ground insulation, with strong compressive strength.

Kumen:

Function: It is the channel for goods to enter and exit, and also the place where cooling capacity is most easily lost.

Type: Depending on the usage scenario, there are sliding doors (saving internal space), hinged doors (similar to household doors), electric rolling shutter doors, and free doors (quick access, commonly used in logistics channels).

Ground insulation and antifreeze measures:

Function: To prevent the cold from the ground from being transmitted to the foundation, which may cause frost heave and cracking of the foundation.

Method: For low-temperature cold storage, in addition to laying insulation layers on the ground, it is usually necessary to lay electric heating wires or ventilation pipes for heating to prevent soil freezing and damaging the ground.

This is the “heart” and “blood vessels” of the cold storage, responsible for generating cold and delivering it to the warehouse.

Compressor:

Function: The “power source” of the refrigeration system compresses the refrigerant to circulate and transfer the heat inside the storage to the outside.

Common types:

Fully enclosed: Sealed like a compressor in a household refrigerator, with low power, used for micro sized cold storage.

Semi enclosed/vortex type: commonly used in medium-sized cold storage, with high efficiency and easy maintenance.

Screw type: commonly used in large cold storage, with huge power and smooth operation.

Condenser:

Function: Heat dissipation device. Cool the high-temperature and high-pressure gas discharged from the compressor into liquid.

Type:

Air cooling: Blows with a fan like an air conditioner outdoor unit, easy to install, commonly used in small warehouses.

Water cooling: using a water tower to circulate water for cooling, with high heat dissipation efficiency, suitable for medium-sized and above cold storage that requires stable operation.

Evaporative: Combining air and water cooling, it has good energy-saving effect and is common in large cold storage.

Evaporator:

Function: Heat absorbing device. Installed inside the warehouse, the liquid refrigerant evaporates and absorbs heat here, causing the temperature of the warehouse to drop.

Common forms:

Air cooler (ceiling mounted): The most commonly used, it uses a fan to forcefully blow air, which cools down quickly but has a drying effect (suitable for most scenarios).

Duct: Installed around or at the top of the warehouse, it relies on natural convection heat transfer, has no wind sensation, and has good moisturizing effect. It is suitable for goods that need to be stored for a long time and are afraid of drying out (such as meat, garlic, and apples), but it is more troublesome to defrost after frosting.

Expansion valve and pipeline:

Function: Adjust the flow and pressure of refrigerant, and connect various devices.

Refrigerant: A medium used to transport heat, commonly including R22 (gradually phased out), R404A, R134a, R410A, R717 (ammonia, used in large cold storage), etc.

This is the “brain” and “nerve” of the cold storage, responsible for commanding equipment operation and monitoring status.

Cold storage dedicated control box/electrical control cabinet:

Function: Centralize control of the start and stop of compressors, fans, defrosting heating wires, etc.

Function: Includes contactors, thermal relays, overload protectors, etc.

Temperature and humidity controller/display screen:

Function: Set and display the temperature inside the library. Usually, sensor probes are inserted into the warehouse.

Advanced: Medium sized and above cold storage will have a PLC touch screen, which can view historical temperature curves, fault alarm records, etc.

Defrosting system:

Function: If the evaporator works for a long time, it will freeze and frost, affecting the cooling effect and requiring regular melting.

Method: There are usually electric heating defrosting (small storage) and hot gas defrosting (large storage, using hot gas discharged by a compressor).

lighting:

Function: Lighting inside the warehouse.

Requirement: Moisture proof, explosion-proof, and corrosion-resistant cold storage special lights (LED cold storage lights) must be used, and the switch is usually installed on the outside of the warehouse door with indicator lights.

This is a supporting facility for cold storage. Although it is not a direct refrigeration, it is crucial for daily use and cargo safety.

Shelf system:

Function: Improve space utilization and facilitate the stacking of goods.

Types: Light duty shelving, medium duty shelving, heavy-duty crossbeam shelving, and drive in shelving (for large warehouses).

Temperature Monitoring and Recording System :

Function: Real time monitoring of temperature. Once the temperature is abnormal, an alarm can be triggered through a mobile app or SMS. This is a mandatory requirement for pharmaceutical warehouses and high-end food warehouses.

Backup power source (generator):

Function: To prevent sudden power outages from causing a rise in warehouse temperature and damage to goods. For cold storage facilities storing valuable goods or vaccines, a backup power source is essential.

Ventilation and air exchange system:

Function: For cold storage of fruits and vegetables (especially controlled atmosphere storage), fresh air needs to be introduced to remove carbon dioxide and ethylene, preventing fruits and vegetables from spoiling.

Summary diagram: Cold storage workflow

Heat in the warehouse → absorbed by the evaporator → refrigerant turns into gas.

Gas is extracted by the compressor → compressed into high-temperature and high-pressure gas → sent to the condenser.

Condenser heat dissipation → refrigerant returns to liquid.

The liquid is throttled and depressurized through the expansion valve, and then returns to the evaporator to absorb heat again.

Repeatedly, the temperature inside the warehouse decreases.

The electric control box controls the start and stop of all the above links to ensure a constant temperature.

In places like restaurants, hospitals, and delivery services, storing ice the right way really matters. It helps save money and keeps service quality high. The key tool is a commercial cold room. How well you control the temperature, humidity, and how people handle the ice will decide how long the ice lasts and how good it stays. Here’s a simple guide to help you store ice better.

• Water starts to freeze at 0℃, but for fast and strong ice, the machine needs to work in a space below ‌-5℃‌.
• If it’s warmer than that, the ice forms slowly and may crack or stick together.
• Some advanced machines go down to ‌-10℃‌, which makes ice faster and stronger.

✅ Tip: Keep the ice machine room closed. Don’t open it too often—cold air escapes and slows things down.

• For cafes, bars, or food shops, ice is used quickly, so you don’t need extreme cold.
• A regular freezer at ‌-18℃‌ works well to keep ice solid and hard.
• But if the door opens a lot, the temperature jumps up and down, and the ice surface may melt a little and then refreeze—this makes ice blocks stick together.

✅ Tip: Open the door fast, take what you need, and close it—try to keep it under 30 seconds.

• If you need to keep ice for a long time or use it for sensitive jobs (like medical cooling), you need a much colder room.
• Use a deep freezer below ‌-25℃‌.
• Some special freezers go to ‌-30℃ or even -50℃‌. This keeps the center of the ice block very cold and stops it from shrinking over time (called “dry loss” or sublimation).
• The temperature should stay very steady—fluctuations should be less than ±1℃.

✅ Tip: These cold rooms use more power, so only use them when really needed.

• Keep the air in the cold room ‌85% to 95% humid‌.
• Too wet? Ice gets frost on the outside and sticks together.
• Too dry? Ice slowly turns into vapor and gets smaller—this wastes ice and reduces cooling power.

✅ Tip: Use a cold room with humidity control to keep the air just right.

• Cold rooms should have fans (like axial fans) to spread cold air evenly.
• This stops some ice from melting while others stay frozen.
• Good airflow also helps keep the space clean and reduces bacteria growth.

✅ Tip: Don’t pack the room too full—leave space for air to flow around the ice.

• Never just dump ice in a big pile—it will freeze into one solid block.
• Use clean plastic bins, insulated bags, or place ice on pallets.
• Keep different types of ice (like cubes vs. crushed ice) in separate containers to avoid mixing and contamination.

✅ Tip: Use small, labeled containers. It’s easier to grab what you need and keeps things clean.

Summary: 3 Key Rules for Better Ice Storage

‌Right Temperature + Good Humidity + Smart Handling = Less Waste, Better Ice‌

• Pick the right temp: ‌-18℃‌ for daily use, ‌-25℃ or lower‌ for long-term.
• Keep humidity between ‌85%–95%‌ to stop frost and dry loss.
• Use fans for even cooling.
• Store ice in separate containers—don’t let it touch.
• Train staff to work fast, use clean tools, and keep the door closed.

For high-demand uses (like medical or lab work), consider ‌ultra-low freezers + digital temperature monitors‌ to track conditions in real time.

• 1.1 Industrial Cold Storage‌: Ideal for bulk storage of raw materials or finished products.such as meat and seafood in food factories, or vaccines and pharmaceuticals in drug manufacturers.
• 1.2 Commercial Cold Storage‌: Commonly used in supermarkets and restaurants for short-term turnover goods like fruits, vegetables, and dairy products.
• 1.3 Key Point‌: First determine the product type, as different items have varying requirements for temperature and humidity.

• 2.1 Fruit & Vegetable Preservation‌: 0~15°C (maintain freshness, delay spoilage).
• 2.2 Meat Freezing‌: -18°C or lower (long-term preservation, prevent, deterioration).
• 2.3 Special Needs‌: Ice cream requires -25°C; some pharmaceuticals may need -60°C ultra-low temperature storage.
• 2.4 Recommendation‌: Incorrect temperature selection can spoil products, so ensure it matches storage needs.

• 3.1 Cold Storage Size‌: Estimate based on cargo volume. For example, storing 1000 boxes of fruit may require 50㎡, while large equipment needs more space.
• 3.2 Cold Storage Panel Thickness‌: The lower the temperature, the thicker the insulation layer.

Use 10cm thick polyurethane panels for 0°C storage, 15cm for -18°C, and 20cm for ultra-low temperature storage.

• 4.1 Refrigeration Unit : Small cold storage (<50㎡) use air-cooled units (cheap, easy to install); Large cold storage (>100㎡) use parallel screw compressors (efficient, energy-saving).
• 4.2 Air Cooler: Select materials based on temperature. Use copper tubes + aluminum fins for fruit & vegetable storage (rust-resistant); stainless steel for freezer storage ( low-temperature resistant). Avoid iron materials, as they will rust and fail.
• 4.3 Defrosting Methods‌: Water defrosting suits fruit & vegetable chiller storage (low cost); electric heating suits freezer storage (high automation).
• 4.4 Tip‌: Incorrect equipment selection can skyrocket energy consumption—consult an onlykem engineer for matching!

• 5.1 Basic Type‌: Manual switch + thermometer (suitable for small cold storage, lowest cost).
• 5.2 Advanced Type‌: Automatic temperature control (suitable for high-traffic cold storage, reduces, manual inspections).
• 5.3 Note‌: Avoid complex systems unless absolutely necessary.

• 6.1 Small Goods‌: Manual sliding door / Hinge door (cheap).
• 6.2 Large Goods/Forklift Operations‌: Electric sliding lift door (good sealing, prevents, cold air leakage).
• 6.3 Anti-collision Design‌: Add sealing strips to reduce heat loss when opening.
• 6.4 Reminder‌: Wrong door choice can cause cold air leaks and double electricity bills!

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Summary: Three-step Cost-saving Method‌

Define Purpose & Temperature First‌: Avoid “over-cooling”.
Accurately Calculate Size & Equipment‌: Don’t waste space or energy.
Choose Reliable Suppliers‌: Fast after-sales response reduces downtime.

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💡 ‌Cold Storage isn’t “the more expensive, the better” – it’s “the more suitable, the more economical”! Need a specific plan? Leave your requirements – I’ll help you calculate!‌ #Cold Storage Construction #Refrigeration Engineering #Cost Saving Guide