Bridging the Communication Gap Behind Refrigeration System Failures

Ammonia is the backbone of food processing, cold chain, and other operations that rely on refrigeration systems. However, even compliant facilities overseen by qualified engineers can suffer from preventable safety and performance issues. The surprising culprit is not equipment failure or inadequate training, but a more fundamental problem: operational information is never communicated to the right people at the right time.

Common Scenario

In a recent incident, an operator at a food plant recorded a steadily rising condensing pressure in its refrigeration system. The situation was not dramatic, just a gradual upward trend over several shifts. All data was correctly logged, and the issue was mentioned during shift handover meetings. However, no one escalated the finding. Why? Because the system was still running—no alarms, no trips, no incidents.

Four nights later, the rising pressure forced the compressor to unload, causing temperature fluctuations in the blast freezer and cold storage, impacting operations and food product safety. The incident nearly escalated into a situation requiring pressure relief, even though there was no mechanical fault. The system had failed in "communication."

This situation is more common than many familiar with these systems are willing to admit.

Structural Weakness

A pattern recurs among teams managing refrigeration systems:

• Operators collect data and maintain logs
• Maintenance teams fix problems
• Engineers review trends after the fact

But no one is responsible for interpreting subtle deviations early. The result? A perfectly documented problem lacking actionable follow-up.

For teams facing energy efficiency and compliance pressures, this gap between observation and action is not just inconvenient—it is costly, risky, and can even lead to major incidents.

Practical Solution

As an engineer at Cargill, a food systems company, I have been involved in an effort to implement a simple, structured escalation model that has improved system performance. The model addresses process safety management (PSM) issues in three steps.

First, it defines "abnormal" in measurable terms. Rather than relying on intuition, it establishes clear trigger conditions, including the following indicators:

• Condensing pressure 10 psi above rolling baseline
• Recurring oil return alarms
• Vessel liquid levels deviating from normal operating conditions
• Minor vibrations and noise from compressors or pumps
• Unusual frost or ice patterns in abnormal locations
• Random PLC/HMI faults or setpoint drift
• Faint ammonia odor near equipment
• Gradual performance degradation of condensers/air handling units

The list could be longer. The key point is that when these indicators appear, they are automatically flagged as PSM-related anomalies rather than routine observations.

Second, it creates a clear escalation point—a single, accountable role responsible for handling the situation. This role can be the refrigeration supervisor, engineering manager, or PSM lead. In this role, that person—not any on-duty staff—evaluates all anomalies. This eliminates the "not my job" gray area.

Third, it requires the responsible person to address each flagged situation within 24 hours. Each anomaly receives one of the following dispositions:

• Operational adjustment
• Maintenance work order
• Engineering review
• Temporary protective measure
• Short-term monitoring plan

No issue disappears into the abyss of the logbook. Within weeks of implementing this model, early trend detection identified numerous issues that, if left unaddressed, could have escalated into incidents:

• Condenser fan motor bearings and guards nearing failure
• Liquid overflow valve sticking
• Float calibration error threatening vessel stability
• Low liquid vessel levels over the weekend due to uneven load distribution
• PLC communication issues in the machine room

These issues were caught before they could cause energy losses, temperature non-compliance, or ammonia leaks. For plants operating under increasingly stringent safety expectations, this structured communication is a low-cost, high-impact improvement.

Clear Path

In ammonia refrigeration, major incidents rarely stem from dramatic failures. They typically begin with small, visible signals that no one is formally responsible for. If teams want safer, more reliable refrigeration operations, the solution is not adding more paperwork, but establishing clearer escalation paths for the early warning signals we already capture.

Strengthening these communication loops delivers tangible, immediate improvements in plant safety, system stability, and energy performance.