The CW-3000 chiller is a compact, passive cooling unit used to remove heat from CNC water-cooled spindles. To keep your system running efficiently and extend the life of your spindle, it's important to choose the right coolant for your environment and application.

This article walks you through the best coolant options for the CW-3000 and explains the pros and cons of each.

🧪 What Type of Cooling System Is the CW-3000?

The CW-3000 is a radiator-based passive chiller — it does not use a refrigeration compressor. Instead, it cools the spindle by circulating coolant through a radiator and fan system. Because of this, the coolant you use plays a big role in both cooling efficiency and long-term system health.

✅ Recommended Coolant Options

1. Distilled Water (Most Common Choice)

Best for: Normal indoor use in clean, temperate environments

• Pros:

  • Excellent thermal transfer

  • Readily available and inexpensive

  • Won’t cause scaling or mineral buildup

• Cons:

  • Can grow algae or bacteria over time

  • Not ideal below freezing temps

🔧 Tip: Add a few drops of biocide (or aquarium algaecide) to prevent biological growth.

2. Distilled Water + Antifreeze (1:4 to 1:1 mix)

Best for: Environments with freezing risk, or where chillers sit idle for long periods

• Pros:

  • Prevents freezing

  • Adds corrosion resistance

• Cons:

  • Slightly reduces cooling efficiency

  • Some antifreeze types can degrade plastics or seals if not diluted properly

Use RV/marine antifreeze or non-toxic propylene glycol, not automotive coolant (which contains additives for aluminum radiators that aren't needed here).

3. Premixed PC Liquid Cooling Coolants

Best for: Users who want a plug-and-play option with long lifespan

• Pros:

  • Pre-treated with biocide and corrosion inhibitors

  • Available in clear or dyed versions

• Cons:

  • Higher cost

  • Sometimes harder to source locally

Brands like EKWB, Mayhems, and Cooler Master make suitable coolant for this use.

4. Deionized Water (Use with caution)

Best for: Advanced users who maintain their systems carefully

• Pros:

  • Extremely clean and non-conductive (initially)

• Cons:

  • Can become aggressive to metals and plastics over time if not stabilized

  • Not recommended unless you fully understand how to manage re-ionization

🧼 Coolant Maintenance Tips

• Replace coolant every 3–6 months or immediately if it becomes cloudy or discolored.

• Clean your spindle and tubing when changing coolant if you notice deposits or residue.

• Keep your system sealed to reduce evaporation and contamination.

• If you see bubbles, it may be trapped air — try tilting the machine or “burping” the coolant lines.

❌ What Not to Use

Avoid these coolants to prevent clogging, corrosion, or premature wear:

• Tap water: Contains minerals that can cause scale buildup and corrosion

• Straight automotive coolant: Too thick and contains unnecessary additives

• Alcohol-based coolants: Can degrade tubing and seals

🧠 Summary

💬 Still Unsure?

If you're not sure which coolant is right for your setup, reach out to our team. Let us know:

• Your environment (garage/shop/warehouse)

• If you're in a freezing climate

• Whether your chiller runs 24/7 or only during jobs

📩 Contact Support →