Thermogym: The Uncompromising Choice for R717 Ammonia Coils

In the critical world of ammonia (R717) refrigeration and heat pump systems – encompassing both traditional compressor-based and advanced adsorption technologies – material selection for coils is paramount. Ammonia, classified as a B2L refrigerant (low flammability, high toxicity), demands absolute system integrity to prevent leaks. While copper is strictly incompatible, the choice between aluminum, carbon steel, and stainless steel is pivotal.

With Thermogym’s cutting-edge manufacturing, stainless steel coils are now competitively priced with carbon steel, fundamentally shifting the value proposition. This allows our customers to elevate their system’s reliability and safety without incurring a cost penalty.

Eliminating the Inherent Risk of Aluminum

Moisture: The Achilles’ Heel of Aluminum. While aluminum may seem compatible with dry ammonia, the reality of real-world refrigeration systems often includes trace moisture. Even minute amounts of water can react with ammonia and aluminum, leading to rapid, unpredictable, and catastrophic corrosion. This is a well-documented failure mechanism in the industry and a leading cause of premature system failure where aluminum has been used.

Safety Compromise. For a B2L refrigerant like R717, where toxicity is a primary concern, any material that presents a risk of sudden failure is unacceptable. Thermogym does not compromise on safety or longevity, which is why we emphasize materials that are unequivocally compatible with ammonia—even with trace moisture present over decades of operation.

Outperforming Carbon Steel: Beyond Initial Price Parity

The recent price alignment between stainless steel and carbon steel makes the choice clear. Thermogym’s stainless steel coils now offer all the premium advantages without the premium cost, making carbon steel an inferior option for long-term reliability.

Unrivaled Corrosion Resistance (Internal & External)

Internal Purity Protection. While ammonia systems strive for dryness, even minimal moisture ingress over a system’s lifespan can lead to corrosion with carbon steel. Stainless steel provides inherent corrosion resistance internally, acting as a safeguard against system contamination and degradation, ensuring the purity of your R717 charge over decades.

External Environmental Resilience. Carbon steel is highly susceptible to external rust and corrosion, especially in environments where ammonia systems are deployed. Stainless steel, by contrast, provides exceptional resistance to high humidity, sanitation chemicals, and airborne contaminants.

• Food Processing & Cold Storage: Frequent washdowns and organic acids from produce and meat attack carbon steel. Stainless maintains both structure and hygiene.
• Industrial & Chemical Exposure: Carbon steel needs painting and coating. Stainless steel resists rust and reduces maintenance downtime.
• Adsorption Systems: From absorption to desorption, stainless performs across a wide chemical and temperature range.

Superior Durability and Longevity

While carbon steel is known for strength, its vulnerability to corrosion limits its effective lifespan. In contrast, Thermogym’s stainless steel coils are engineered to last decades, delivering a far better return on investment. This durability also reduces maintenance intervals and improves system uptime.

Stainless steel also exhibits superior performance against stress corrosion cracking and thermal fatigue, offering mechanical robustness even under cycling pressures and temperatures.

Enhanced Hygiene and Ease of Maintenance

The smooth, non-porous surface of stainless steel is inherently more hygienic. It resists bacterial accumulation and is easy to clean. This is essential in food and beverage environments where hygiene is both a regulatory and operational priority.

Unlike carbon steel, which can degrade under strong chemicals, stainless steel can withstand aggressive cleaning agents and high-pressure washing without compromising performance or structure.

Safety for B2L Refrigerants

R717’s toxicity requires the highest level of material integrity. Thermogym’s stainless steel coils offer a stable, corrosion-free system envelope that drastically reduces the risk of leaks. This ensures safety for personnel and minimizes environmental hazards while extending the life of the system.

Applications

Thermogym’s stainless steel coils are ideal for both compressor-based industrial refrigeration and cutting-edge adsorption chillers using ammonia. Their robust construction ensures performance across the full range of pressures and temperatures associated with R717-based technologies.

Available Sizes

We manufacture stainless steel tubes in a wide range of diameters, from compact 7 mm outer diameter options to heavy-duty 5/8 inch OD formats. These cover the needs of compact chillers, large evaporators, and every application in between.

Why Settle? Upgrade with Stainless Steel Fins

Looking for even more durability? Combine your Thermogym stainless steel coils with our stainless steel fin option. By eliminating the galvanic corrosion risk of aluminum fins, the all-stainless assembly achieves unmatched resistance in harsh environments. This not only extends service life but ensures thermal performance remains consistent, year after year. Learn more about stainless steel fins here.