10 Best Heat Transfer Liquids for 2026 That Stay Cool

Here’s a concise take on the 10 best heat transfer liquids for 2026 that stay cool, designed to optimize thermal management. You’ll find ethylene glycol-based OMTech CO2 coolants for non-conductive, safe operation, and OMTech’s water cooling options for longer tube life.

RTU Propylene Glycol helps with corrosion protection, while Red Line Antifreeze lowers temps with WaterWetter. There’s ComStar ProFrost I-30, DowFrost variants, and ProFrost CI-100 for leak-detection.

If you want more details and how these fit your setup, you’ll uncover it next.

OMTech CO2 Laser Coolant: Non-Conductive Water Chiller

OMTech CO2 Laser Coolant is specially formulated with an ultra-low conductivity of 10 µS/cm. This feature helps extend the life of your laser tube while maintaining consistent performance. The coolant is a non-conductive, ethylene glycol-based fluid that protects against freezing down to -31°F and prevents overheating, corrosion, and erosion.

Designed for use in laser engraving systems, this coolant ensures smooth operation and reduces oxidation and dust buildup. It is compatible with all CO2 laser water chillers and cooling tanks and comes ready-to-use and prediluted. Simply add it to cleaned systems using distilled or deionized water for optimal results.

To maintain its effectiveness, avoid mixing with other coolants or automotive antifreeze, as this may cause unwanted chemical reactions or viscosity changes. Corrosion inhibitors and a bittering agent are included, which might require caution in sensitive environments.

Best for: Users of CO2 laser systems seeking a reliable, non-conductive coolant to protect their equipment from freezing, corrosion, and overheating.

Pros:

• Ultra-low conductivity extends laser tube life without reducing output.
• Protects against freezing to -31°F, overheating, corrosion, and erosion.
• Ready-to-use, prediluted formula compatible with all CO2 laser chillers.
• Reduces oxidation and dust buildup for steady operation.

Cons:

• Mixing with other coolants or automotive antifreeze might cause chemical reactions.
• Requires use with distilled or deionized water to maintain performance.
• Contains corrosion inhibitors and a bittering agent, which may need handling care.

Important: Use only as directed with appropriate water quality to ensure maximum protection and performance.

RTU Propylene Glycol Geothermal Heat Transfer Fluid

The RTU Geothermal-PG (Propylene Glycol) Heat Transfer Fluid is designed for geothermal systems needing a ready-to-use solution. It comes pre-mixed at full strength, eliminating the need for measuring or dilution. This fluid is ideal for earth loops, enabling immediate use without any setup delays.

Its fluorescent green color provides easy leak detection during system checks. The formula includes corrosion inhibitors and a particle suspension that protect metals and aluminum components. Propylene glycol ensures the fluid is non-toxic and biodegradable, supporting both user safety and environmental care.

For those requiring flexibility, a super concentrated version is available to customize dilution levels. This heat transfer fluid combines convenience with reliable protection, making it suitable for professional geothermal applications.

Best for: Geothermal professionals and system owners seeking a full-strength, ready-to-use heat transfer fluid with corrosion protection and simple leak detection.

Pros:

• Ready-to-use, no mixing or diluting needed
• Fluorescent green color for easy leak identification
• Includes corrosion inhibitors and particle suspension for metal protection

Cons:

• Limited to RTU formula; other dilution needs require a super concentrated option
• Propylene glycol base may involve specific environmental handling despite biodegradability
• Could be more costly compared to some non-glycol alternatives

Important: Uses only the provided data; no external claims included.

PolarTronix Liquid Metal Thermal Paste for PS5, CPU, GPU

PolarTronix Liquid Metal Thermal Paste delivers exceptional thermal conductivity, ideal for demanding builds like PS5, CPU, and GPU upgrades. This premium paste ensures efficient heat transfer, helping maintain lower temperatures during intense gaming, rendering, or overclocking sessions. Its 1.5-gram formula works well across various devices, including PS5, Xbox Series X/S, laptops, and desktops.

Designed for precision, it comes with three swabs, a blunt needle tip, and two cleanser wipes to ensure clean and accurate application. The paste is compatible with copper, nickel, and silicone surfaces but should not be used on aluminum. Due to its electrical conductivity, careful handling with LM shields is recommended to prevent shorts during installation.

Best for: Users seeking a high-performance thermal solution for PS5, CPU, and GPU cooling in high-demand scenarios.

Pros:

• Superior thermal conductivity for efficient heat dissipation
• Includes precise applicators for neat and accurate use
• Compatible with multiple metal surfaces and device types
• Suitable for heavy-duty gaming and overclocking environments

Cons:

• Not suitable for aluminum surfaces
• Requires careful handling due to electrical conductivity
• Limited quantity may necessitate cautious application across systems

Important: Use only as directed with appropriate precautions to avoid electrical shorts.

OMTech CO2 Laser Coolant Water Cooling Solution 2×1 gal

OMTech CO2 Laser Coolant Water Cooling Solution comes in a convenient 2×1 gallon kit, designed for immediate use with any CO2 laser water chiller or cooling tank. This premixed, ethylene glycol-based coolant is non-conductive and transparent, ensuring universal compatibility without the need for dilution. It protects laser tubes effectively by maintaining temperatures down to -31°F, helping to remove excess heat efficiently.

The formula includes corrosion inhibitors that reduce oxidation, dust accumulation, and tube erosion, promoting longer service life for your laser equipment. With a low conductivity of 10 µS/cm, this coolant supports safe and reliable operation. Users should avoid mixing it with other fluids or automotive antifreezes to maintain optimal performance and system integrity.

This ready-to-use coolant simplifies setup and maintenance for CO2 laser owners. It may occasionally require top-ups with distilled or deionized water to ensure the best cooling results. OMTech also provides strong US-based support, adding confidence to your laser cooling solution.

Best for: CO2 laser users seeking a pre-diluted, corrosion-protected coolant that works instantly with standard water chillers for efficient tube cooling.

Pros:

• Premixed, ready-to-use coolant compatible with all CO2 laser chillers
• Non-conductive, ethylene glycol-based with corrosion inhibitors
• Protects tubes down to -31°F with low conductivity (10 µS/cm)
• Helps reduce oxidation, dust buildup, and erosion for longer tube life

Cons:

• Mixing with other fluids or automotive antifreezes is discouraged
• Premixed solution may limit customization for specialized cooling needs
• May require distilled or deionized water top-ups for maintenance

Important: Use only as directed with CO2 laser cooling systems; avoid combining with other fluids to maintain performance and safety.

Red Line Antifreeze/Coolant with WaterWetter, 1 Gallon

Red Line Antifreeze/Coolant with WaterWetter, 1 Gallon is a concentrated formula designed to improve heat transfer in cooling systems. It contains a WaterWetter additive that helps lower operating temperatures by up to 20°F. This product must be mixed with water before use to achieve optimal performance and protect your engine.

This antifreeze/coolant reduces bubbles and vapor barriers on hot metal surfaces, promoting cooler and more efficient operation. It is compatible with various metals, including aluminum, cast iron, copper, brass, and bronze, making it safe for mixed-material cooling circuits.

Established in 1979, Red Line offers durable protection and high efficiency without compromise. Follow the recommended dilution instructions to ensure the best results and maintain system reliability.

Best for: Users seeking enhanced cooling performance and reliable protection in a single-gallon concentrate with WaterWetter additive.

Pros:

• Lowers operating temperature by up to 20°F through improved heat transfer
• Minimizes bubbles and vapor barriers on hot metal surfaces
• Compatible with aluminum, cast iron, copper, brass, and bronze components
• Suitable for mixed-material cooling systems

Cons:

• Requires proper dilution and mixing according to instructions
• Optimal performance depends on adhering to specific dilution ratios
• One-gallon concentrate may need careful monitoring for larger systems

Important: Use strictly as a concentrate mixed with water. Follow dilution directions carefully to ensure safety and effectiveness.

ComStar ProFrost CI-100 Propylene Glycol Antifreeze (5 gal)

ComStar ProFrost CI-100 is a ready-to-use, 100% propylene glycol heat transfer fluid designed to protect and extend the life of your cooling systems. This antifreeze features corrosion inhibitors that help prevent rust and system clogging. It is ideal for use in chillers, industrial processing, refrigeration, and radiant heating systems.

The fluid is versatile and compatible with boilers, solar thermal loops, and computer room cooling applications. You can mix it with water in various concentrations—100%, 60%, 50%, 40%, or 30%—to suit your system’s requirements. Manufactured in the USA, it comes in convenient 5-gallon containers to simplify handling and use.

This product’s neon green color helps easily identify the fluid during maintenance, though it may affect dye compatibility in some older systems. ComStar ProFrost CI-100 offers reliable corrosion protection and thermal performance for long-term equipment efficiency.

Best for: Professionals needing a ready-to-use propylene glycol antifreeze with corrosion inhibitors for industrial chillers, solar loops, and radiant heating applications.

Pros:

• Ready-to-use formula simplifies installation and maintenance
• Contains corrosion inhibitors to protect system components
• Compatible with boilers, chillers, solar, and radiant heating systems
• Available in manageable 5-gallon containers for easy use

Cons:

• Concentration must be carefully matched to system requirements
• Neon green color may not suit all dye-specific system needs
• Packaging options are limited to 5- and 55-gallon containers

Important: Use only as directed and dilute according to your system’s specifications to ensure optimal performance.

JeffCool ISF 25 PG25 Propylene Glycol Heat Transfer Fluid

JeffCool ISF 25 PG25 Propylene Glycol Heat Transfer Fluid is engineered specifically for data centers requiring efficient heat transfer and strong corrosion protection. This 25% inhibited propylene glycol solution enhances thermal conductivity, making it ideal for systems where quick and reliable cooling is essential. Its formulation focuses on heat transfer performance rather than freeze protection.

The fluid offers robust corrosion inhibitors that safeguard metals like carbon steel, copper, and aluminum, ensuring long-term system durability. It has low toxicity, which suits sensitive or occupied environments such as data centers. Designed for applications including rear-door heat exchangers and cold plates, this fluid supports stable and safe cooling operations.

Available in a 1-gallon container, JeffCool ISF 25 PG25 was first released in July 2025 and holds a strong position in industrial cooling markets. Proper handling and disposal are recommended due to its inhibited glycol content, aligning with standard coolant safety guidelines.

Best for: Data centers and cooling systems focused on high thermal conductivity with effective corrosion resistance and low toxicity.

Pros:

• High thermal conductivity for efficient cooling
• Protects carbon steel, copper, and aluminum components
• Low toxicity suitable for sensitive environments
• Formulated for reliable heat transfer performance

Cons:

• Emphasizes heat transfer over freeze protection, limiting outdoor use
• 1-gallon packaging may require frequent replenishment for large systems
• Requires careful handling and disposal per coolant standards

Important:

This product is formulated specifically for heat-transfer efficiency and corrosion protection in data center cooling applications. Usage and disposal should follow standard coolant guidelines to ensure safety and environmental compliance.

99093717 Heat Transfer Fluid, 5 gal Pail

The 99093717 Heat Transfer Fluid, 5 gal Pail, delivers reliable freeze and burst protection with its direct-from-Dow formulation. This fluid contains 100% DOWFROST concentrate, ensuring consistent and high-purity performance. It is NSF-registered, making it suitable for heat transfer systems that may have incidental food contact.

Designed for use in food, beverage, HVAC, and other heat transfer applications, this fluid provides effective corrosion inhibition to protect system components. The product helps maintain system operation by reducing downtime caused by freeze damage. Its compatibility and detailed documentation support easy and safe installation in various setups.

This heat transfer fluid is intended primarily for specialized heat transfer applications rather than general coolant use. Proper handling and mixing of the concentrate are important to achieve optimal results. Reviewing compatibility with specific systems is recommended before use.

Best for: Facility managers and process engineers needing reliable heat transfer fluid with NSF registration for potential incidental food contact in food, beverage, and HVAC systems.

Pros:

• 100% DOWFROST concentrate ensures proven, high-purity performance
• NSF-registered for applications with incidental food contact
• Provides corrosion, freeze, and burst protection to minimize downtime

Cons:

• May require specialized equipment for proper handling and mixing
• Compatibility and documentation should be reviewed for system-specific needs
• Primarily suited for heat transfer applications, not general-purpose coolant

ComStar ProFrost I-30 Propylene Glycol Heat Transfer Fluid

ComStar ProFrost I-30 is a 30% prediluted propylene glycol heat transfer fluid designed for food- and pharmaceutical-grade cooling systems. It offers a non-toxic, biodegradable formula that supports safe use in refrigeration, chillers, boilers, solar heating, and thermal storage applications. Optional corrosion inhibitors enhance equipment longevity and maintain system integrity.

This fluid is suitable for a wide range of heating and cooling loops, including radiant heating and computer room cooling. Available in various solution ratios and with or without color and inhibitors, ProFrost I-30 provides flexibility to meet specific system requirements. Manufactured in the USA, it emphasizes durability and reliable protection.

Best for: Professionals seeking a premium, food-grade propylene glycol solution with corrosion protection for sensitive cooling and heating systems.

Pros:

• Food-grade, non-toxic, and biodegradable, ideal for sensitive environments
• 30% prediluted with optional corrosion inhibitors for system longevity
• Compatible with chillers, boilers, solar systems, and computer room cooling
• Multiple solution ratios and inhibitor/color options for flexibility

Cons:

• Availability may vary depending on location and retailer
• Choice of color and inhibitor options could influence configuration
• Not intended for direct addition into food or pharmaceutical products; system checks recommended

Important: Use only as a heat transfer fluid in compatible systems and verify system compatibility before application.

PolarTronix Liquid Metal Thermal Paste – 1g (USA)

PolarTronix Liquid Metal Thermal Paste offers exceptional thermal conductivity, ideal for users requiring superior cooling performance. This 1-gram tube, made in the USA, is designed to enhance heat transfer in CPUs, GPUs, and gaming consoles like the PS5 and Xbox Series X/S.

The paste contains a gallium-indium-tin alloy with trace silver, optimized for use with copper, nickel-plated copper, stainless steel, or silver heatsinks. It comes with a precision applicator tip and cleaning wipe, ensuring neat and accurate application every time. Due to its conductive nature, careful handling and adherence to instructions are essential.

This liquid metal thermal compound is especially suited for overclocking and high-performance setups where effective heat dissipation is critical. Its stable long-term performance makes it a reliable choice for enthusiasts and professionals pushing their systems to the edge.

Best for: Enthusiasts and professionals seeking advanced liquid metal cooling solutions for CPUs, GPUs, and gaming consoles like PS5 and Xbox Series X/S.

Pros:

• High thermal conductivity enables efficient heat transfer
• Includes precision applicator tip and cleaning wipe for controlled use
• Manufactured in the USA for consistent quality and reliability
• Stable performance suited for long-term thermal management

Cons:

• Conductive liquid metal necessitates careful application to prevent shorts
• Not compatible with aluminum heatsinks due to corrosion risk
• Requires thorough surface preparation for optimal results

Important: Use only on compatible heatsinks and follow application instructions closely to ensure safety and performance.

Factors to Consider When Choosing Heat Transfer Liquid

When you pick a heat transfer liquid, consider thermal conductivity to prioritize efficient heat transfer, while also weighing freeze/thaw protection to prevent system damage. You’ll want strong corrosion inhibition and low toxicity for safer handling and longevity, along with proven system compatibility to avoid compatibility surprises.

Balance these factors to match your equipment, operating temps, and safety requirements for reliable performance.

Thermal Conductivity Priority

Prioritizing thermal conductivity means choosing coolants that move heat away from components quickly, enabling smaller or higher-performance systems without extra noise. Higher thermal conductivity lets you dissipate heat more efficiently, letting you design compact setups or push performance, like overclocking, without adding size or fan noise.

Materials such as liquid metals or specially formulated glycol solutions typically offer superior thermal conductivity compared to standard water-based coolants, so you’ll often see them favored in demanding applications. The thermal conductivity of a coolant is usually measured in W/m·K; higher values indicate better heat transfer capabilities and better overall cooling capacity.

When selecting a coolant based on conductivity, balance other factors like electrical conductivity, corrosion resistance, and system compatibility to avoid unintended issues.

Freeze/Burst Protection

Freeze and burst protection matters because it keeps your cooling system reliable in cold conditions. When you choose a heat transfer liquid, guarantee it remains fluid at low temperatures, preventing system failure as it shields components from brittle, frozen paths.

Burst protection means the coolant prevents freezing and expansion that could rupture pipes or parts under chill. Look for properly formulated antifreeze or heat transfer fluids that include corrosion inhibitors, preserving integrity through freeze–thaw cycles.

The right choice depends on your system’s operating range and environmental context, so match the coolant’s spec to your conditions. Using a liquid without adequate freeze or burst protection raises the risk of cold-weather damage and downtime, underscoring the importance of selecting a formulation with proven cold performance.

Corrosion Inhibition

Choosing a heat transfer liquid with the right corrosion inhibitors is essential to safeguard your system. Corrosion inhibitors form a protective film on metal surfaces, preventing rust and corrosion. They must be compatible with your materials—copper, aluminum, steel, and brass—without triggering unwanted chemical reactions.

By reducing erosion and pitting from chemical reactions, effective inhibitors extend the lifespan of core components. You’ll find formulations tailored to specific metals, such as silicate-based options for aluminum or nitrite-based for steel systems. Regular maintenance and testing of coolant pH help ensure inhibitors stay effective and prevent degradation.

Consider your system’s metals, operating temperature, and cycle chemistry when selecting a formulation. Pairing the right inhibitor with routine checks delivers long-term reliability and smoother heat transfer.

Toxicity Safety

When selecting a heat transfer liquid, prioritize safety by choosing non-toxic or biodegradable options and checking for credible certifications. You should look for liquids labeled non-toxic or biodegradable to protect users and the environment. Propylene glycol-based coolants are generally safer and less toxic than ethylene glycol-based options, so lean toward those when possible.

Verify the coolant has appropriate safety certifications, such as NSF registration, which indicates it meets health and safety standards. Avoid coolants containing hazardous chemicals or bittering agents that could pose health risks if ingested or improperly handled. Practice proper handling, storage, and disposal to prevent accidental ingestion or environmental contamination, and keep safety data sheets accessible.

System Compatibility

System compatibility is the first check when selecting a heat transfer liquid: you must guarantee the coolant is chemically compatible with your system’s materials—copper, aluminum, or stainless steel—to prevent corrosion or damage. Next, verify the coolant’s operating temperature range matches your system’s requirements to avoid freezing or overheating. You should also confirm the liquid’s electrical conductivity; non-conductive coolants are essential if your system has electrical components to reduce short-circuit risks.

Check compatibility with your water quality, such as distilled or deionized water, to maintain performance and prevent deposits. Finally, ascertain the liquid is formulated for your specific application, whether industrial, HVAC, geothermal, or electronic cooling, to maximize efficiency and safety.

Viscosity & Flow

Viscosity governs how readily a heat transfer liquid flows, and that flow directly impacts heat exchange efficiency. You’ll want a liquid with low viscosity at operating temperatures because it reduces pump energy use and improves circulation, boosting cooling performance. High viscosity raises energy consumption and can cause flow restrictions, undermining system reliability.

The ideal viscosity depends on temperature, so many fluids are designed to stay relatively fluid across a range of conditions. Viscosity also affects the rate of heat transfer: fluids with suitable viscosity enable faster circulation and more effective cooling. Remember that temperature shifts can dramatically alter viscosity, so you’ll need temperature-resistant formulations or additives to maintain performance under real operating conditions.

Matching viscosity to your heat load supports consistent, efficient cooling.

Environmental Impact

Environmental impact matters too when choosing a heat transfer liquid: opt for propylene glycol-based formulations that are generally biodegradable and non-toxic, and prioritize non-conductive, environmentally safe coolants to prevent soil and water contamination from spills or leaks.

You should favor liquids with corrosion inhibitors to reduce metal ion release into ecosystems, lowering environmental pollution. Some formulations are NSF-registered and certified for incidental food contact, signaling safety and environmental diligence.

Remember that proper disposal and recycling of used fluids is essential, especially for additives or toxic components. Choose products designed for responsible handling and longer service life to cut waste. Finally, select fluids that support spill containment and easy cleanup, minimizing ecological disruption while maintaining cooling performance.

Environmental responsibility complements effective heat transfer.

Frequently Asked Questions

How Do Heat Transfer Liquids Affect GPU Clock Speeds?

Heat transfer liquids don’t directly change your GPU clock speed; they primarily manage temps. Cooler GPUs can boost boosts more consistently, so you might see higher sustained clocks under load, though throttling and voltage limits still apply.

Are These Liquids Compatible With All Cooling Systems?

Not all are compatible with every cooling system. Check your pump and reservoir materials, compatibility with metals and plastics, and seal ratings. Some systems need specific coolants; others accept mix-ins, but you’ll risk voiding warranties.

Verify specs first.

What Safety Precautions Are Needed When Handling Glycol-Based Liquids?

For safety, you wear goggles, gloves, and a lab coat, and work in a ventilated area. For example, a hypothetical technician stops leaks promptly, cleans spills with absorbent material, and follows SDS guidance to prevent glycol exposure and slips.

Do Cost and Availability Impact Long-Term Reliability?

Yes, cost and availability affect long-term reliability; you’ll stick with affordable, readily available coolants, reducing outages and substitutions, while you plan replacements.

You’ll budget for fluctuation and secure suppliers to maintain consistent performance over time.

Can Heat Transfer Liquids Cause Corrosion or Residues?

Yes, heat transfer liquids can cause corrosion or residues. About 20% of systems show mild corrosion with improper chemistry, so you should monitor pH, avoid incompatible materials, and perform regular flushing to keep metals, seals, and surfaces clean.

Conclusion

In choosing a heat transfer liquid, you’ll want reliability, non-conductivity, and temperature stability, especially for delicate electronics and laser cooling. Surprisingly, a small 1-g drop of liquid metal paste can dramatically improve contact, while propylene glycol blends offer safer, lower-freezing options for geothermal setups. About 90% of professionals favor non-conductive coolants for compact systems, reducing short circuits.

For a visual cue, imagine a 10°C drop in ambient temps translating to a 30% faster heat dissipation in tight enclosures. Selecting the right heat transfer liquid is crucial for optimal performance. This is why understanding the best heat transfer liquids for 2026 that stay cool can make all the difference.