Remote control and automation to optimize cold storage for fruit and vegetables

Cold storage of fruit and vegetables requires stable conditions to be maintained for periods that can vary considerably depending on the product, its intended market and the storage strategy. Temperature, humidity, ventilation, defrosting and equipment operation must all be coordinated to prevent deviations and respond quickly to changing facility requirements.

Dithmarscher Kältetechnik, a German company specializing in refrigeration and air-conditioning systems, develops installations for growers, distributors, transport companies and operators that store and dispatch fresh produce. Among the equipment used to manage these projects are VDH’s MC2-FC and MC3-FRUIT controllers.

The collaboration between the two companies enables the control system to be tailored to each installation while retaining access to its parameters once the cold rooms are operational.

Refrigeration systems tailored to each project

Dithmarscher Kältetechnik supports its customers from the initial planning stage through to commissioning. Its work includes refrigeration system design, quotation preparation, control panel development and final delivery.

Thies Oelrichs, a master refrigeration technician at the company, explains that many of its customers operate in the agricultural and fresh produce sectors:

“Our customers are mainly agricultural businesses. Many of our projects involve the storage of fruit and vegetables. We also work with suppliers, buyers and transport companies that store and distribute these products.”

This approach requires each project to be adapted to factors such as the number of cold rooms, storage volume, cooling cycles, defrosting system, and ventilation and humidification requirements.

Temperature, humidity and ventilation control

The MC2-FC is a controller specifically developed for cold rooms and fruit storage facilities. It controls, monitors and records temperature, humidity and ventilation, while also managing refrigeration, fans, humidification and various defrosting systems.

The controller distinguishes between three operating modes. During cooling, it activates the refrigeration system according to the cold room’s demand. In storage mode, cycles can be coordinated so that several controllers within the same network do not cool simultaneously, thereby reducing the required compressor capacity. In standby mode, the cold room only operates when it needs to supply hot gas to another unit undergoing defrosting.

The touchscreen displays system parameters and operating status. Inputs and outputs can also be expanded using additional modules when more sensors or relays are required.

According to Oelrichs, ease of use is one of the features most highly valued by customers:

“The MC2 and MC3 controllers are easy to use. The interface is intuitive and straightforward, with the technology streamlined to the essentials. If an installation has a requirement that the controller cannot handle as standard, VDH works to develop a tailored solution.”

Centralized management of multiple cold rooms

For larger facilities, the MC3-FRUIT centralizes the management of multiple cold rooms and coordinates more than one hundred controllers over an Ethernet network. Installed in the main electrical control panel, the system monitors the different stages of storage and preservation. Operating programs are configured by entering the parameters required for each process, while its modular architecture allows the number of inputs and outputs to be expanded according to the installation’s needs.

The MC2-FC can also communicate with MC3-FRUIT systems. This makes it possible to integrate individual cold rooms into a broader control network while retaining autonomous operation in the event of a communication failure. This capability is particularly useful in storage facilities with multiple cold rooms, different products or storage programs that do not require the same conditions at all times.

Remote adjustments and alarms

One of the features highlighted by Dithmarscher Kältetechnik is remote access to installations through VASP, VDH’s platform for monitoring controllers, reviewing records, managing alarms and changing settings.

Remote access allows the installer and customer to review cold room operation together, even after the installation has become operational. Certain parameters can therefore be adjusted without waiting for an on-site visit, which is especially valuable when projects are located far from the technical service team’s headquarters.

Oelrichs says:

“We can adjust the settings together with the customer once the installation is already operating. This is extremely useful because we build refrigeration systems across Germany and even in Poland”.

Remote monitoring does not replace equipment maintenance or regular sensor inspections, but it facilitates the detection of deviations, the monitoring of storage conditions and a faster response to alarms or changes in product requirements.

The combination of local control, coordination between cold rooms and remote access therefore makes it possible to adapt refrigeration system operation to the demands of fresh produce storage while maintaining continuous visibility of the main storage parameters.

More information