Single-Stage Data Center Cooling: A Dober Coolwave™ FAQ

 

This simplifies system design, reduces energy loss, and improves heat transfer efficiency. COOLWAVE™ is engineered for this direct-contact duty.

WHAT IS A SINGLE-STAGE DATA CENTER COOLANT?

A single-stage coolant is a ready-to-use heat transfer fluid designed for direct use in data center cooling loops, such as rear-door heat exchangers, cold plates, or immersion systems.

 

Unlike two-stage systems (which use intermediate heat exchangers and multiple fluids), single-stage coolants circulate directly through the cooling equipment, simplifying the system and improving efficiency.

WHAT IS IT MADE OF?

Most single-stage data center coolants are based on glycol-water blends (propylene glycol or ethylene glycol) combined with:

• Corrosion inhibitors (to protect metals like aluminum, copper, brass, and steel)
• pH stabilizers
• Biocides (to prevent microbial growth)
• Defoamers and dye tracers

Premium coolants (like Dober’s COOLWAVE™) use low-conductivity formulations to maintain electrical safety in liquid cooling systems.

WHY IS ELECTRICAL CONDUCTIVITY IMPORTANT?

Because single-stage coolants may come into close proximity with electronics (in direct-to-chip or rear-door systems), low conductivity minimizes the risk of short circuits if leaks occur.

Coolants are engineered to start with conductivity typically below 1,000 µS/cm, and formulations are designed to resist conductivity rise over time due to oxidation or ion pickup.

WHAT MAKES A DATA CENTER COOLANT DIFFERENT FROM AUTOMOTIVE ANTIFREEZE?

While both use glycol bases, data center coolants are formulated for:

• Electrical safety (low ionic content)
• Extended fluid life and stability
• Non-reactivity with sensitive alloys and elastomers
• Lower foaming tendencies
• Tighter particle and contaminant control (filtration and cleanliness levels suitable for IT systems)
• Automotive antifreeze often contains silicates and additives that can foul microchannels or plate exchangers used in data center systems.

WHAT TEMPERATURE RANGE CAN IT HANDLE?

Typical operating ranges:

• Freezing protection: down to -40 °C (-40 °F) depending on concentration
• Boiling point: typically above 105 °C (221 °F)

However, system design and coolant composition determine exact limits.

HOW OFTEN SHOULD IT BE REPLACED?

Most engineered coolants are rated for 3–5 years of service, depending on:

• System design (open vs. closed loop)
• Exposure to air and contaminants
• Temperature cycling
• Maintenance practices (e.g., filtration, top-off with deionized water only)

Regular testing (pH, inhibitor level, conductivity, freeze point) helps extend life and prevent corrosion.

IS IT COMPATIBLE WITH COPPER, ALUMINUM, AND MIXED-METAL SYSTEMS?

Yes — high-quality single-stage coolants include a multimetal corrosion inhibitor package that protects:

• Copper and brass
• Aluminum
• Steel and stainless steel
• Soldered joints

Formulations are also tested against common elastomers (EPDM, Viton, NBR) for long-term seal integrity.

WHAT ARE THE ENVIRONMENTAL OR SAFETY CONSIDERATIONS?

• Low toxicity: Propylene glycol-based fluids like COOLWAVE are safer for personnel and the environment than ethylene glycol.
• Biodegradability: Many are readily biodegradable under OECD standards.
• Non-flammable: When used at normal operating concentrations.
• Low vapor pressure: Reduces emissions and fluid loss.
• Always follow local environmental and disposal regulations — fluids can often be recycled or reconditioned.

CAN IT BE MIXED WITH OTHER COOLANTS?

Mixing is not recommended.  Each coolant has a unique additive and corrosion package — mixing can reduce inhibitor performance, increase conductivity, or cause precipitation. If switching brands or types, flush and clean the system before refilling.

HOW DO I MONITOR COOLANT HEALTH OVER TIME?

Routine monitoring should include:

• pH: keep between 7.5 – 9.5
• Conductivity: stay below manufacturer’s threshold, often < 2,000 µS/cm
• Freeze point: via refractometer
• Visual inspection: clarity, color, no suspended solids
• Some advanced systems use in-line sensors or predictive monitoring for conductivity and corrosion potential.

WHAT’S THE TOTAL COST OF OWNERSHIP (TCO) ADVANTAGE?

While fluid cost per gallon may be higher than generic glycol, total system savings come from:

• Reduced downtime (due to corrosion and failure prevention)
• Improved thermal efficiency (lower ΔT across the loop)
• Extended equipment life
• Lower maintenance and replacement frequency
• In many deployments, payback occurs within 12–24 months through energy and maintenance savings.

WHAT IS COOLWAVE™?

COOLWAVE™ is Dober’s engineered single-stage data center coolant, purpose-built to protect and optimize high-performance cooling systems.

It’s a low-conductivity, propylene glycol-based fluid designed for direct-to-chip, rear-door, and liquid-to-liquid heat exchange systems where reliability, safety, and thermal efficiency are critical.

WHAT MAKES COOLWAVE™ DIFFERENT FROM STANDARD GLYCOL COOLANTS?

Most industrial or automotive glycols are designed for engines — not servers. COOLWAVE™ is formulated specifically for data center environments, offering:

• Ultra-stable low conductivity to safeguard sensitive electronics
• Corrosion inhibitors tuned for mixed-metal systems (copper, aluminum, steel, brass)
• Microbial and fouling control for clean, long-lasting operation
• High thermal stability under continuous high-load operation
• Zero silicates, phosphates, or borates that can clog or foul microchannels

It’s cleaner, safer, and more reliable than conventional glycol-water blends.

 

WHY IS LOW CONDUCTIVITY IMPORTANT?

Electrical safety. In high-density racks or direct-to-chip systems, even a small leak can be catastrophic with standard fluids. COOLWAVE™ is formulated for ultra-low initial conductivity (< 1,000 µS/cm) and is chemically stabilized to resist conductivity drift over time — maintaining electrical safety throughout the fluid’s service life.

IS COOLWAVE™ COMPATIBLE WITH MY EXISTING SYSTEM MATERIALS?

COOLWAVE™ includes Dober’s advanced multi-metal corrosion protection package, proven compatible with:

• Copper, brass, aluminum, and stainless steel
• Common elastomers such as EPDM, Viton, and NBR
• Plastics used in hoses and fittings
• Its non-aggressive chemistry helps extend the life of pumps, seals, and cold plates.

HOW LONG DOES COOLWAVE™ LAST?

Under typical closed-loop operation, COOLWAVE™ provides 3–5 years of reliable service life. Longevity depends on factors like exposure to oxygen, temperature, filtration, and top-off water quality. Routine testing (pH, conductivity, freeze point) ensures consistent protection and performance.

WHAT MAINTENANCE IS REQUIRED?

We recommend:

• Annual or semi-annual sampling for pH, inhibitor strength, and conductivity
• Top-offs only with deionized water or premixed COOLWAVE™
• Periodic inspection of filters and strainers
• Dober offers COOLWAVE™ monitoring kits and support for on-site analysis or lab testing.

WHERE IS COOLWAVE™ USED?

COOLWAVE™ is trusted in:

• Data centers and edge facilities using liquid cooling
• AI and HPC (high-performance computing) clusters
• Colocation and hyperscale environments
• Telecom, medical, and industrial cooling systems seeking improved thermal control

It’s engineered for environments where uptime, reliability, and safety are non-negotiable.

HOW DOES COOLWAVE™ LOWER TOTAL COST OF OWNERSHIP (TCO)?

By combining thermal efficiency, corrosion protection, and long life, COOLWAVE™ helps reduce:

• System downtime and maintenance costs
• Component wear and corrosion-related failures
• Coolant replacement frequency
• Energy use through improved heat transfer

The result: lower lifetime cost and higher operational reliability.

WHAT ARE THE AVAILABLE FORMULATIONS AND FREEZE PROTECTION LEVELS?

Pre-mixed, ready-to-use (no further dilution required):

• COOLWAVE DC-25: 25% USP-grade propylene glycol — freeze protection down to ≈ –10 °C / 14 °F
• COOLWAVE DC-25: 30% USP-grade propylene glycol — freeze protection down to ≈ –7.9 °C / 13.4 °F
• COOLWAVE DC-55: 55% USP-grade propylene glycol — freeze protection down to ≈ –40 °C / –40 °F

WHAT IS THE CORROSION PROTECTION PERFORMANCE?

COOLWAVE DC is tested under ASTM D8040 conditions (including modified OCP / cold-plate protocols) and demonstrates:

ASTM / OCP Limit (mg mass loss)	Material	COOLWAVE DC average (mg)	Pass Y/N?
≤ 10 mg (modified OCP)	Copper	~1 mg	YES
≤ 10 mg	Brass	~1 mg	YES
≤ 10 mg	Steel	~0 mg	YES
≤ 10 mg	Cast Iron	~0 mg	YES
≤ 30 mg	Cast Aluminum	~1 mg	YES
≤ 30 mg	Solder	~2 mg	YES

Thus, COOLWAVE DC is broadly compatible with mixed-metal systems (copper, brass, aluminum, steel, solder) under test conditions

WHAT IS THE ELECTRICAL CONDUCTIVITY/LOW IONIC BEHAVIOR?

COOLWAVE is designed to maintain ultra-low electrical conductivity, critical in direct-to-chip and sensitive systems.

The exact starting conductivity and drift limits (µS/cm) should be obtained from the full TDS (not publicly disclosed in summary). 

The coolant is designed to resist rapid conductivity increase over time, helping preserve electrical safety margins.

WHAT MATERIALS (ELASTOMERS, METALS, PLASTICS) IS IT COMPATIBLE WITH?

COOLWAVE DC is engineered for compatibility with:

• Metals: copper, brass, aluminum, steel, stainless steel, soldered joints
• Elastomers and seals: EPDM, FKM, PTFE, and similar high-performance polymers
• Common plastics and tubing used in cooling loops (assuming no aggressive additives)
• Because the additive package is non-aggressive, degradation or swelling of seals is minimized

WHAT IS THE RECOMMENDED OPERATING TEMPERATURE / THERMAL RANGE?

While full TDS would give exact thermal limits, from the public spec:

• The coolant’s freeze protection is tied to glycol concentration (–10 °C for DC-25, –40 °C for DC-55) com
• It is designed for single-phase liquid cooling loops, operating well within typical data center temperatures (e.g. 5 °C to ≈ 60–70 °C)
• The additive system must remain stable at elevated temperatures under continuous operation
• Boiling limits depend on system pressure, but typical liquid cooling loops do not exceed ~ 100 °C

HOW LONG IS THE SERVICE LIFE?

The expected service life is multiyear (3–5 years is a common target for engineered glycol systems) under closed-loop operation with proper filtration, inert gas blanketing or de-aeration, and periodic monitoring. The additive package is designed to remain effective over time, resisting depletion or degradation under normal data center cycles. 

WHAT MAINTENANCE OR MONITORING IS REQUIRED?

To maintain performance and safety, you should:

• Periodically test pH, conductivity, freeze point
• Monitor any drift in corrosion rates (via test coupons if practical)
• Inspect for color change, presence of particulate matter, or precipitates
• Use only deionized water or compatible fluid for top-offs
• Verify that the seal materials and piping remain in good condition
• Refer to the full TDS for acceptable ranges and thresholds.