Grain Bin Temperature Control Unit

Selecting the appropriate grain storage air conditioner requires comprehensive consideration of factors such as the size of the grain storage, storage requirements, and environmental conditions. The following are detailed selection steps and key points:
1. Clarify the basic parameters of the grain storage
Measure the dimensions of the grain storage
Record the length, width, and height of the grain storage (in meters) and calculate the volume (Volume = Length × Width × Height). This is key data for determining the cooling capacity of the air conditioner.
For example: A grain storage measuring 20 meters long, 15 meters wide, and 8 meters high has a volume of 20×15×8=2400 cubic meters.
Understand the characteristics of the stored items
Different grains (such as rice, wheat, corn, etc.) have different temperature and humidity requirements for storage. Generally, the recommended storage temperature for grains is 15-25°C, with humidity at 60%-70% RH.
If storing high-moisture grains or perishable crops, stricter temperature and humidity control is required, which may necessitate an air conditioner with greater cooling capacity and dehumidification capabilities.
Evaluate the insulation performance of the grain storage
Check the thickness and sealing of the insulation materials (such as polyurethane foam, rock wool, etc.) in the walls and roof of the grain storage. Poor insulation will increase the air conditioning load.
If the grain storage has windows or ventilation openings, consider sealing measures or additional cooling loss.
2. Calculate the cooling capacity requirements of the air conditioner
Basic cooling capacity calculation
Generally estimated based on the volume of the grain storage, with a reference standard of 100-150W of cooling capacity per cubic meter of space (adjusted based on insulation conditions).
Example: For a 2400 cubic meter grain storage, the basic cooling capacity = 2400×120 (taking the median value) = 288,000W ≈ 288kW.
Additional load calculation
Heat dissipation from personnel/equipment: If there are ventilation fans or lighting equipment in the grain storage, add their power (e.g., 10 fans at 1kW each, total heat dissipation of 10kW).
Solar radiation: For south-facing exterior walls and roofs of the grain storage, increase the cooling capacity by 10%-20% (depending on local sunlight intensity).
Door-opening heat load: Frequent entry and exit into the grain storage will introduce heat. Calculate based on 10 door openings per day, with each opening adding 5kW.
Final cooling capacity determination
Total cooling capacity = Basic cooling capacity + Additional load. It is recommended to reserve a 10%-20% margin on this basis to avoid insufficient performance due to load fluctuations.
For example: 288kW + 20kW (additional load) = 308kW. After reserving a 20% margin, an air conditioner with approximately 370kW of cooling capacity is required.
3. Select the type and functions of the air conditioner
Select the type based on the scale of the grain storage
Grain Storage Scale Recommended Air Conditioner Type Features
Small grain storage (<500m³) Split-type air conditioner (cabinet unit / wall-mounted unit) Flexible installation, low cost, suitable for independent small spaces, but requires multiple units for coverage and has higher energy consumption.
Medium grain storage (500-2000m³) Ducted central air conditioner Provides even air distribution through ducts, more precise temperature and humidity control, centralized management, suitable for multi-compartment grain storage.
Large grain storage (>2000m³) Screw-type / centrifugal chiller unit + terminal units High cooling capacity (hundreds to thousands of kW), high energy efficiency, suitable for very large grain storage, requires piping and fans.
Key functional requirements
Dehumidification function: Grain storage is sensitive to humidity. The air conditioner must have an independent dehumidification mode, with dehumidification capacity calculated at 1-2L/h per 100m³ of space.
Constant temperature control: The temperature fluctuation range should be ≤±1°C. Choose an air conditioner with PID adjustment function to prevent grain mold due to sudden temperature changes.
Ventilation circulation: The air conditioner must be paired with fans to ensure an air velocity of 0.5-1m/s in the grain storage, avoiding uneven local temperature and humidity.
Smart monitoring: Choose an air conditioner with remote monitoring functionality to view temperature and humidity data in real time and support mobile app alerts (e.g., automatic notifications when temperature exceeds limits).
4. Consider energy consumption and installation requirements
Energy Efficiency Ratio (EER/COP)
Prioritize high-efficiency products, e.g., EER≥3.0 (split-type), COP≥3.5 (central air conditioning), to reduce long-term operating costs.
For large grain storage, consider inverter air conditioners that automatically adjust power based on load, achieving more significant energy savings (over 30% more efficient than fixed-speed units).
Installation location and piping design
The outdoor unit of the air conditioner should be installed in a well-ventilated area away from heat sources (e.g., on the north side of the grain storage to avoid direct sunlight).
Indoor units or ducts should be evenly distributed to ensure cold air covers the entire grain storage, avoiding dead spots (e.g., installing ducts at the top to direct air downward).
Pipe insulation should use B1-grade rubber-plastic materials to prevent condensation from affecting grain quality.
Explosion-proof and moisture-proof design
If the grain storage holds grains that emit volatile gases (e.g., oil crops), choose an explosion-proof air conditioner (compliant with GB3836 explosion-proof standards).
The air conditioner housing should undergo anti-corrosion treatment, as high humidity in the grain storage can cause metal components to rust and deteriorate.
5. Reference cases and brand recommendations
Case references
Small grain storage (300m³): Choose 2 split-type cabinet units of 12kW each (total cooling capacity 24kW), paired with an independent dehumidifier with a dehumidification capacity of 30L/h. Cost is approximately 15,000 RMB.
Large grain storage (5000m³): Use 1 screw-type chiller unit of 200kW, paired with 20 fan coil units. Total investment is approximately 250,000 RMB, with annual energy consumption of about 120,000 kWh.
Brand recommendations
Domestic mainstream brands: Gree (specialized grain storage air conditioner series), Midea (strong adaptability to low-temperature environments), Haier (comprehensive smart monitoring system).
Specialized industrial brands: York (large chiller unit solutions), Carrier (high-efficiency screw machines), DunAn (rich experience in explosion-proof air conditioning).
6. Precautions
Regular maintenance: Clean the air conditioner filter and check refrigerant pressure quarterly; perform pipeline sterilization and disinfection annually to avoid mold contamination of grains.
Integrated ventilation: The air conditioner can be integrated with the grain storage’s existing ventilation system. When outdoor temperature and humidity are suitable, prioritize natural ventilation to reduce energy consumption.
Emergency plan: Equip backup power or standby air conditioner units to prevent grain spoilage due to power outages or equipment failures.
By following the above steps, you can select the appropriate air conditioner based on the actual size and needs of the grain storage, ensuring safe grain storage with energy efficiency. If there are special requirements (e.g., extremely high-temperature regions, high-altitude environments), it is recommended to consult a professional refrigeration engineer for a customized solution.