A Practical Guide to Glycol Chiller Systems: Design, Control and Installation Explained

What Are Glycol Chiller Systems?

Across the UK, glycol chiller systems support industries that rely on accurate temperature regulation. From breweries and dairies to laboratories and manufacturing plants, these systems provide consistent cooling performance using a solution of glycol blended with water to transfer heat.

Unlike standard water chillers, glycol chillers use a mixture of propylene or ethylene glycol combined with water. This makes them suitable for applications operating below 0°C or installations with outdoor pipework exposed to cold weather.

At a fundamental level, glycol chiller systems remove heat from a process and transfer it away through a refrigeration circuit. The cooled glycol solution is then pumped through pipework to absorb heat from equipment or products before returning to the chiller.

How a Glycol Chiller System Works

Effective system design ensures consistent output and reduced energy consumption. Core components typically include:

• Refrigeration compressor


• Condenser


• Evaporator heat exchanger


• Metering device


• Glycol reservoir and pump


• Electrical control system

Within the evaporator, the refrigeration cycle extracts thermal energy from the secondary fluid. The chilled solution is then distributed to the application, where it absorbs heat before returning.

A typical glycol chiller system diagram shows the separation between the primary refrigeration loop and the secondary glycol circuit. The refrigeration loop manages heat removal, while the glycol loop transfers chilled fluid to the point of use. Accurate schematics are valuable for installation, servicing and fault finding.

The Control Panel: Managing Performance and Safety

The glycol chiller system control panel acts as the operational centre of the system. Modern panels typically include:

• Programmable temperature regulation


• PLC or microprocessor interfaces


• Pressure protection cut-outs


• Pump sequencing controls


• Fault indication systems


• Remote monitoring capabilities

The control panel manages compressor cycling, supervises operating conditions and ensures safety limits are maintained. Many systems also log performance data to support preventative maintenance and compliance documentation.

In facilities requiring precise cooling, reliable control minimises fluctuations that might compromise process stability.

Control Panel Installation Considerations

Proper glycol chiller system control panel installation is essential for safe operation and long-term reliability. Key factors include:

• Electrical compliance – Connections must align with UK wiring regulations and include suitable isolation and circuit protection.


• Location and ventilation – Panels should be located in dry, well-ventilated areas away from excessive heat, vibration or moisture.


• Commissioning procedures – Post-installation checks must include sensor accuracy, alarm testing and pump sequencing confirmation.

Commissioning ensures the unit operates in line with the original glycol chiller system design specifications.

Key Factors in System Design

Effective glycol chiller system design begins with accurate assessment of the cooling load. Engineers evaluate:

• Required temperature range


• Flow rate and pipe sizing


• External temperature influences


• System resilience planning


• Allowance for capacity growth

Correct sizing is essential to avoid inefficiency or inadequate cooling. Load calculations must consider peak demand and operational cycles.

Fluid selection also plays a role. Propylene glycol is commonly used in food and beverage settings due to its lower toxicity, whereas ethylene glycol may be selected for industrial environments requiring improved heat transfer efficiency.

Additional considerations such as insulation standards, pump capacity and exchanger design influence stability, efficiency and lifespan.

Where Glycol Cooling Is Used

Glycol chiller systems support numerous sectors across the UK, including:

• Breweries and distilleries


• Food manufacturing plants


• Pharmaceutical production environments


• Laser and medical equipment cooling


• Manufacturing and moulding operations


• Cold storage and preparation areas

For example, in beverage production, chillers maintain fermentation temperatures and cool storage tanks. In manufacturing settings, they protect equipment from excessive thermal build-up.

Protecting System Performance

Routine maintenance supports efficient operation and reduced downtime. Typical servicing tasks include:

• Checking glycol concentration levels


• Assessing circulation components


• Removing debris from heat rejection surfaces


• Verifying control panel settings


• Monitoring refrigerant pressures

Over time, glycol can degrade or become contaminated, reducing heat transfer efficiency. Regular testing helps maintain optimal performance.

When correctly designed, installed and maintained, glycol chiller systems can provide reliable service for many years.

Common Queries About Glycol Chiller Systems

What is the typical glycol percentage?

Most UK systems operate with a concentration between 20% and 40%.

Can a glycol chiller be installed outdoors?

Yes, provided the unit is rated for outdoor use and protected against environmental exposure.

How does a glycol chiller differ from a water chiller?

Unlike water-only systems, glycol-based chillers resist freezing and support sub-zero applications.

Is remote access available?

Advanced control panels often provide remote monitoring and data logging functionality.

What is the recommended testing frequency?

Fluid condition should be reviewed regularly based on system workload.

Where are they most commonly used?

Industries requiring stable and low-temperature control frequently depend on glycol-based systems.

Final Considerations

Glycol chiller systems deliver dependable cooling performance across a broad range of industrial and commercial applications. From accurate load calculation and correct commissioning through to routine servicing, every stage affects efficiency and longevity.

Whether planning a new installation or upgrading existing equipment, engaging knowledgeable engineers helps align system capacity with process needs. For technical advice and tailored solutions, consult the Newsome glycol chillers page to explore engineered glycol cooling solutions designed for long-term performance.