The biggest problems experienced in cold rooms are insulation weakness, insufficient cooling system and unplanned operations.
The use of panels that do not comply with the standard in cold storages causes excessive heat loss. It is best to use a locked sandwich panel in accordance with the standard and to use it with sufficient thickness.
another is that a door and door rims of poor quality will always cause heat loss. It is best to use isothermal cold room doors.
Cooling systems are another problem. Since the unsuitable cooling system in the cage will always cause consumption of electricity, electricity will be twice your need.
sharpso industrial Cooling Systems , we are constantly sharing our page for you to read, our company for cold rooms Sandwich locked panel isothermal cold room doorsand all designs related to cold room are made by himself. In addition, our cold room cooling systems are our own production.
Experiencing cold storage issues? Failure to detect problems can result in crop failure while in cold storage.
This information page cold room It lists some of the most common problems found in Windows, along with possible causes and solutions.
cold storage It's always a good idea to have regular checks and maintenance to make sure it's structurally fit and working properly.
A cold storage contractor can assist in preparing an inspection and maintenance program. Some solutions can be resolved by the storage owner, while others must be handled by a qualified contractor.
This information page covers the following causes and possible solutions:
Some products freeze.
Some products are wrinkled.
Some products sweat or have free water on them.
The product shows early ripening, discoloration, loss of leaves (plants).
The product has odors or bad tastes.
The product is rotting.
Building Related
Walls and/or ceiling condensation or moldy.
The walls and/or ceiling are rotting.
The ceiling is dripping.
Even when water is sprayed on the floor, the floor dries.
The indoor temperature fluctuates during the storage period.
Indoor air temperature is warmer than desired during storage.
During the storage period, the indoor air temperature is colder than desired.
Indoor air temperature is not homogeneous.
Storage air smells bad or is difficult to breathe.
Evaporator coils are icing up and too much condensate is flowing.
Electricity consumption is increasing.
Product Problems
Possible causes:
Possible solutions are:
Thermostat set too cold, differential too wide, or thermostat (or sensor) positioned poorly.
Set the thermostat to a higher temperature. Reduce the temperature difference (on-off). Relocate or replace the thermostat (or sensor).
The product is stacked too high and in the airflow directly from the coils.
Avoid stacking the product too close to the airflow from the coils. Install baffles under the coils to direct the cold air above the product.
The product is touching the freezer walls or too close (in the winter or if it is next to a freezer).
Re-insulate, especially on concrete foundations, and keep the product away from cold walls.
Evaporator coils are dirty or one or more of the fans are not working, causing the outgoing air temperature to be cooler.
Clean evaporator coils or repair fans.
One coil may not be working properly (with more than one coil), causing the air temperature from the other coils to be colder.
Have a technician check the coils and valves for correct refrigerant flow, operating pressure and temperatures (superheat settings).
Bad airflow.
Use a smoke generator to find dead air spots. Replace the coils or increase the fan capacities. Install air tubes and/or extra circulation fans. Place containers to ensure good air distribution.
Storage relative humidity is too low.
Clean the evaporator coils (if dirty). Replace inoperative fans.
Control the frequency of defrosting (duration and termination) as this can add excessive heat to the room or allow excessive frosting between cycles.
Have the system and coils checked by a contractor for efficient operation and proper operating temperatures. Adjust the superheat settings on the expansion valves.
Have a contractor check system sizing (compressor and evaporator coil sizing and temperature difference under actual design conditions).
Increase the coil size or install more coils so they can operate with a lower temperature difference between the "cold" air coming out of the coils and the air that the product "feels". This reduces the humidity of the air.
Install humidification equipment that can provide ultrafine or atomized mist (it is difficult to put water back into the dried product).
While the product is hot and humid, cold air is dry and draws moisture out. The vapor pressure difference is too high.
Remove field heat faster and faster after harvest so there is less vapor pressure difference between crop and storage air. Thus, moisture is less encouraged to leave the product and cause drying.
Wooden containers and the storage structure itself draw moisture from the air and from the product.
Wet wooden containers before placing them in long-term storage. Tests show that wooden drums can absorb moisture and increase their weight by 10%.
Products such as stone fruits appear wrinkled when lightly frozen.
See possible solutions below freeze. Slightly frozen stone fruits do not shrink due to moisture loss and
Possible solutions:
Hot, humid air is entering the room through the door openings or there is an air leak. room.
Reduce infiltration of hot air by minimizing door opening time, installing a strip curtain (or air curtain), preventing wind pressure and/or cooling of the adjacent area.
Hot, moist air from the newly placed product hits the cold product.
Store the "cold" product longer in a separate room from the "hot" product being refrigerated. Install more cooling to reduce significant increases in air temperature.
After the product is taken out of the warehouse, warm, humid air condenses on the cold product.
Let the product warm up gradually; Condensation is inevitable if the product is placed directly in a hot, humid atmosphere or if air conditioning is added for the packaging area.
The defrost time may be too long and/or the termination may not be working, causing the room temperature to become too high.
Control the defrost frequency, duration and termination to avoid adding excessive heat to the room.
Defrosting water from evaporator coils dripping onto product
Drain condensate away or onto the floor if possible to help humidify the tank.
Humidification system droplets are too large, or the humidity setting is set too high or out of calibration.
Install humidification equipment that can provide ultra-fine or atomized mist, or that can adjust, calibrate, or replace the moisture meter.
Ethylene gas may be present.
Remove high ethylene producing fruits (e.g. apples, pears, melons, plums, peaches, apricots, melons, tomatoes) from the landfill. Avoid using forklifts that emit ethylene in the exhaust. Ventilate storage rooms thoroughly before use. Also, ventilate during use, provided there is sufficient cooling to handle the extra load from ventilation.
The storage temperature may be too high.
Lower the storage temperature. If insufficient, add more cooling.
Defrost cycles are too long and/or add too much heat to the room.
Check the defrost for correct frequency, duration and termination.
The product is stacked too tightly, preventing it from cooling.
Leave space between rows and layers of products and stack them to allow good airflow through them.
Products nearby that easily transmit odors and/or bad tastes.
Remove crops such as cabbage, turnips, celery, potatoes, onions, lettuce or garlic.
Possible solutions: The
product is very hot and breathing and ages rapidly.
It provides rapid and homogeneous rapid cooling after harvest. Maintain the recommended temperature throughout the storage period.
Before storage, the product is damaged, overripe or of poor quality.
Increase separation rates before storage. Don't expect storage to turn a poor quality product into a top quality product with a long shelf life.
Interior surfaces are cooler than impinging room air. Surface temperatures and humidity levels are ideal for mold growth.
Apply more insulation to warm wall surfaces above the dew point (condensation) of the room air. Tighten the building and provide better airflow in these areas.
Excessive humidity or hot humid air enters the room.
Reduce infiltration of hot air by minimizing door opening time, installing a strip curtain (or air curtain), preventing wind pressure, and/or cooling the adjacent area.
The insulation in the ceiling or walls is saturated.
Remove wet insulation. Allow the surfaces to dry and replace the insulation with adequate spray foam insulation.
Moisture penetration into wood cladding/structure.
Before rebuilding, determine why and how you can prevent moisture from re-entering
Improper installation or missing vapor barrier.
If necessary, determine the appropriate vapor barrier location.
Incorrect type of insulation used or insufficient insulation value installed.
If necessary, re-insulate, possibly with a different insulation.
Water leaking from roof or other sources.
Repair and dry the roof or any other source of water leakage or wet insulation etc. change it.
Inadequate roof ventilation causing a build-up of hot, humid air in the attic.
m21 unlimited eaves ventilation area. , same unrestricted overhead ventilation area or mechanically ventilate at 1 air change/2 minutes
Insufficient attic insulation causing condensation dripping from cracks.
Remove wet insulation. Allow surfaces to dry and replace insulation with adequate spray foam insulation
Improper installation or incomplete vapor barrier.
Add enough insulation to prevent the temperature on the warm side from cooling to the dew point (condensation) of the warm air in the attic. The vapor barrier position depends on the steam pressure drive direction (hot side). Depending on the building use, a vapor barrier may not be recommended.
Install more coils so they can operate with a lower temperature difference between the "cold" air coming out of the coils and the air that the product "feels". This reduces the humidity of the air. Install humidification equipment that can provide ultrafine or atomized mist, it is difficult to put water back into the dried product.
The floors have cracks for water to escape.
Irrigate the floor to see if the water is running, especially along the concrete foundation. Seal if necessary.
Possible solutions are: The
thermostat is not placed properly and is not detecting the average room temperature.
Install thermostats to the average room airflow, usually the return airflow to the evaporator coils. Place thermostats away from hot/cold walls, doors, lights, cold air from coils or hot product.
Poor quality or insensitive thermostats (differential too wide).
Recalibrate or replace thermostat including differential. Use good equipment, as uniform temperature control is vital to maintaining product quality.
Defrost cycles are not set or not working properly, causing excessive icing between cycles or adding too much heat to the room.
Airflow is not uniform throughout storage.
Use a smoke generator to locate dead air spots. Relocate the evaporator coils or increase the capacity of the fans (if possible). Install air tubes and/or extra fans. Rearrange storage containers for smoother airflow.
Insufficient cooling.
Install more cooling cooling capacity.
Insufficient insulation for summer use.
Install a minimum of R-20 on the walls, R-24 in the attic and R-12 in the foundation. Floors are rarely insulated in Ontario, but the cost can be justified for year-round use.
Poor roof ventilation.
same, 1 m2 unlimited eaves ventilation entrance area for each 600 m2 ceiling. Provide unlimited overhead ventilation area or mechanically ventilate at 1 air change/2 minutes
Hot sunny days with a dark roof surface.
Paint the roof white with chalk and provide adequate attic ventilation if the roof is a dark color as attic temperatures can reach 60°C.
Airflow is not smooth or insufficient storage capacity.
Use smoke generators to locate dead air spots. Relocate the evaporator coils or increase the capacity of the fans (if possible). Install air tubes and/or extra fans. Rearrange storage containers for smoother airflow.
Poor thermostat location that senses cold temperatures.
Install thermostats to the average room airflow, usually the return airflow to the evaporator coils. Avoid placing thermostats on cold exterior walls, near doors, or near evaporator coils venting from cold air.
Thermostat is misplaced and detects higher temperatures.
Install thermostats to the average room airflow, usually the return airflow to the evaporator coils; Avoid location thermostats on hot exterior walls or near doors or lights.
Insufficient insulation for winter use.
Install minimum R-20 on walls, R-24 in attic and R-12 on foundation. Floors are rarely insulated in Ontario, but the cost can be justified for year-round use.
Air flow is uneven or insufficient for product capacity in storage.
Shorting of air directly to evaporator coils due to poor container arrangement.
Avoid passages/openings that allow air to bypass product or storage containers. Air will always choose the easiest path, and air must be forced to go a meandering path to maximize its cooling potential. Use a smoke generator to check for a short circuit.
Gases such as carbon dioxide or ethylene may be present in excess as a result of decay or respiration.
Look for rotting product and dispose of it. Install a small exhaust fan that provides ventilation with 1 or 2 air changes per day. Some new tanks (not built as Controlled Atmosphere tanks) are very tight so there is no natural air exchange ventilation.
operating at too low temperature
Clean the coils and make sure all fans are blowing in the correct direction.
Increase the coil temperature. This may require larger capacity evaporator coils.
The defrost system is not working properly.
Repair the defrosting system or install a more efficient system, as the relative humidity must be high for most products.
Storage relative humidity is high.
Some crops such as onions, garlic or zucchini require lower humidity.
Insulation is wet or missing.
Correct the humidity problem and re-insulate with insulation more suitable for cold storage.
A higher volume of product is cooled than before.
Install more cooling as crop production increases. Size the system appropriately to reduce costs.
The product enters the warehouse warmer than in previous seasons.
Older varieties and variable weather conditions may mean that the harvested product is warmer and requires more cooling capacity than before.
Less tight buildings or doors open more frequently.
Re-tighten the building as they become less tight over time. Attach the flaps to the access doors.
Dirty evaporator coils or condenser coils (in outdoor units).
Clean the evaporator and condenser coils.
Defective refrigeration equipment.
Have equipment serviced by a qualified refrigeration contractor who knows the needs of farm products.
Cold storage Keeping the build and cooling system in optimum condition will help ensure a high quality product and meet processor and retail demand for longer periods of time. Some issues can be resolved using warehousing techniques, but others will need to be handled by a qualified contractor. Use the tables above to assist with identity resolutions and get problems fixed quickly.