How to Choose the Right coolant for Industrial Chiller?

💡What Cooling Medium Should I Choose?

💡 Purpose of Coolant Liquids

In industrial cooling and temperature control systems, liquids serve as the medium for heat transfer and heat removal.
They can effectively reduce and control equipment or process temperature,
preventing overheating that may lead to dimensional drift, reduced machining accuracy, and unexpected downtime.
The right coolant not only enhances heat dissipation efficiency but also provides lubrication and flushing between the tool and workpiece,
reducing friction and wear, removing chips and particles, extending machine lifespan and maintenance intervals,
while stabilizing process quality and improving productivity and yield.
For different applications (spindle cooling, laser equipment, semiconductor, and power electronics),
selecting the appropriate cooling medium and concentration, together with filtration and anti-corrosion strategies,
ensures that the cooling capacity of the chiller and the overall system performance are fully realized.

---

Six Key Considerations Before Choosing Coolant

1️⃣ Identify the type of cooling system

First, clarify what kind of system requires cooling : 
Is it fluid temperature control for an oil tank/water tank, spindle cooling, thermal management of electronic control systems,
or process heat load removal (such as laser, injection molding, EDM, or battery testing)?

Different systems have very different requirements for thermal conductivity, dielectric properties (whether conductive),
viscosity, cleanliness, and allowable material compatibility.

📌 Example:

• Spindles often prefer low-viscosity oil.
• Lasers usually use pure water or water–ethylene glycol.
• Semiconductor or high-voltage power electronics may require non-conductive fluorinated liquids.

Define the system first, then match the coolant type, concentration, circulation flow, and filtration grade, to ensure correct chiller selection at once.

2️⃣ Identify the target of cooling

Common configurations include:
📍 Spindle：Recommended spindle lubrication oil (spindle oil), ensuring high-speed bearing lubrication and heat removal.
📍 Laser machines：Usually adopt pure water or glycol–water solution for high thermal conductivity and antifreeze protection.
📍 Special semiconductor processes：Recommended fluorinated liquids (non-conductive, good material compatibility).
📍 Electrical cabinets / power module cold plates: Pure water with corrosion inhibitors, or non-conductive fluorinated liquid if necessary.
📍 EDM (electrical discharge machining)：Commonly deionized water; if oil-based medium is used, oil-resistant materials are required.
📍 Battery testing / charging equipment：Glycol–water solution (control freezing point, stable heat capacity).
📍 Optical equipment / medical imaging：High-purity water or low-conductivity formula to reduce contamination risk.
📍 Servo motor water jackets：Pure water or water–glycol with anti-corrosion additives, balancing heat transfer and material protection.
📍 Other scenarios may be evaluated as needed.

3️⃣ Working environment

Environmental conditions directly affect coolant selection and formulation.

• In low-temperature environments, freezing point must be considered.
  Pure water may freeze, so antifreeze agents (ethylene glycol/propylene glycol) should be added with controlled concentration.
• In high-temperature environments, evaporation and boiling points must be considered;
  pressure may need to be increased or higher-boiling formulas chosen.
• In dusty, oily, or metallic particle environments,
  filtration and sealing must be reinforced to prevent contamination from entering the circulation and affecting the heat exchanger,
  pumps, and valve lifespan.
• In salt-mist or chemically corrosive environments,
  corrosion-resistant materials and anti-corrosion additives are required to ensure long-term chiller stability.

4️⃣ Coolant performance

Key physical properties include specific heat, thermal conductivity, viscosity, boiling point, freezing point, dielectric properties, and chemical stability.

• High specific heat and good thermal conductivity enable rapid heat removal.
• Viscosity affects pump power consumption and flow rate (which in turn affects heat exchange efficiency).
• Suitable boiling and freezing points ensure year-round usability.
• For coolant paths close to electronic components, non-conductivity is a critical safety requirement.

First define performance indicators, then match cooling capacity, pump flow rate, heat exchange area,
and piping materials to design a more efficient, low-energy, and long-lasting cooling system.

5️⃣ Corrosiveness

If coolant has corrosive or oxidative tendencies, system materials must be upgraded
(such as stainless steel, special coatings, corrosion-resistant plastics) as well as sealing material levels,
and corrosion inhibitors/pH buffers should be added to maintain chemical stability.

Neglecting corrosion control may lead to pipeline leakage, heat exchanger perforation, pump failure,
r even environmental pollution and safety incidents caused by leaks.
Regularly monitoring conductivity, pH, metal ions, and suspended solids—
together with filters and bypass filtration—can minimize risk.

6️⃣ Cost considerations

Total cost includes not only purchase price but also filling volume, replenishment frequency, filter consumables,
treatment/recycling fees, energy consumption, and downtime maintenance costs.

For the same oil chiller, different oil types may vary greatly in unit cost and replacement cycle.
It is recommended to evaluate using Life Cycle Cost (LCC) analysis to find the optimal balance between performance and budget.

🌎 Common Coolant Liquids 🌎

 

 

 

 

 

 

 

 

 

 

📌 Cutting fluid

Widely used in milling machines, lathes, gear machining, and various machine tools.
⭕ Advantages: Removes cutting heat, forms lubrication film, flushes chips and particles, maintains surface condition with anti-rust additives.
                             Greatly improves machining surface quality and tool life.
❌ Limitations: Requires proper waste fluid management and skin/mist exposure control,
                             as well as regular monitoring of concentration and contamination to prevent degradation and odor.
✏️ Selection recommendation: Choose water-based or oil-based formulas according to process and material.
(For oil systems, common viscosity grades ISO VG6–VG32 are available for KAUKAN oil chillers; for other models, consult manufacturer.)

📌 Spindle oil / spindle lubrication oil

Mainly used for spindles and high-speed, low-load bearings.
⭕ Advantages: Low viscosity, low friction, anti-wear and anti-oxidation.
                             Quickly forms lubrication film at high speeds and removes heat, maintaining bearing precision and lifespan;
                             also provides rust prevention and thermal stability.
❌ Limitations: Not suitable for heavy-load or impact-load scenarios; requires regular replacement based on cleanliness and oxidation.
                             Higher cost than general oils, and requires correct viscosity grade selection (e.g., ISO VG6–VG32).
✏️ Selection recommendation: Choose water-based or oil-based formula depending on process and material.
(For oil systems, ISO VG6–VG32 viscosity grades are suitable for KAUKAN oil chillers; for other models, consult manufacturer.)

📌 Pure water

Common in injection molding, laser processing, medical equipment, and PCB manufacturing.
⭕ Advantages: High specific heat, good thermal conductivity, low cost, rapid heat absorption, and stable temperature field.
❌ Limitations: Easily freezes at low temperature, may corrode metal parts, and high conductivity may affect sensitive circuits.
✏️ Practical use: Usually combined with antifreeze and anti-corrosion additives, with conductivity control.
                             Together with stainless materials, closed circulation, and filtration, efficiency and reliability can be ensured.

📌 Ethylene Glycol (EG)

Suitable for injection molding, laser, medical equipment, PCB, and year-round temperature control.
⭕ Advantages: Lowers freezing point, raises boiling point, provides corrosion resistance and thermal stability,
                             miscible with water in any ratio for flexible freezing point adjustment, and relatively cost-effective.
❌ Limitations: Risk of crystallization at low temperature, long-term compatibility issues with rubber seals,
                             corrosion risk from acidic byproducts after oxidation, and toxicity management required.
✏️ General recommendation: ~30% EG concentration (for KAUKAN oil chillers; for other models, consult manufacturer),
                                                with regular testing and reinforced anti-corrosion/anti-oxidation measures.

📌 Fluorinated liquids (electronics-grade non-conductive coolants)

Commonly used in electronic equipment, power modules, and semiconductors.
⭕ Advantages: Non-conductive, chemically inert, thermally stable, compatible with most materials, allows immersion cooling,
                             improves heat dissipation efficiency, and reduces noise.
❌ Limitations: Higher fluid cost, requires tight leakage prevention and recovery management, some formulas involve PFAS regulations requiring careful evaluation.
                             Maintenance must consider replenishment and filtration costs. For high reliability and electrical safety, fluorinated liquids are a strong option.

⚠️ Notes on Using Coolant ⚠️

📌 Follow manufacturer recommendations
Chillers are designed considering fluid type, volume, and flow rate. Operate and fill according to manufacturer specifications to keep cooling capacity,
compressor, and pump efficiency at their best.

1️⃣ Regular replacement and filtration

Coolant quality directly affects heat exchanger and pump life.
In dusty or oily environments, install filters/cartridges and replace regularly to ensure clean medium enters the KAUKAN chiller.
(KAUKAN provides compatible filter materials. Contact us for details.)

2️⃣ Avoid ingestion / misuse

Some coolants are colorless, odorless, and look alike. Clear labeling and color-coded containers are required.
If contact with skin or eyes occurs, rinse immediately with plenty of clean water; seek medical help if discomfort arises.

3️⃣ Pay attention to fill level

Insufficient liquid may cause dry running, cavitation, or protective shutdown; excessive liquid may cause overflow.
Maintain recommended liquid level per sight glass and specification, and confirm circulation before startup.

4️⃣ Power-off during replacement

When adding/replacing coolant, turn off power first to avoid pump accidents or fluid splashing. Ensure correct venting and sealing.

5️⃣ Consult professional manufacturers

For regulations (e.g., refrigerant/environmental), material compatibility, or customization, discuss with professional engineering teams.
KAUKAN chillers can provide on-site evaluation and formula recommendations for greater peace of mind.

✅ Conclusion

Choosing a coolant requires consideration of chiller specifications, working environment, heat load,
material compatibility, maintenance cost, and regulatory risks.
It is recommended to integrate fluid performance, concentration, filtration,
corrosion protection, and safety management from a system perspective, and adjust according to manufacturer recommendations.
Through life-cycle thinking, the optimal solution balancing performance and cost can be achieved.

If further evaluation based on actual site conditions is needed,
KAUKAN chillers can provide professional selection and formula advice to help you build a stable,
efficient, and long-lasting industrial cooling system.