I. Material and Process: Surface Treatment Determines Basic Performance Differences

The production process for steel finned tubes is relatively simple. After the fins are combined with the tube body through winding, welding, or stamping, only basic rust removal treatment (such as acid washing and phosphating) is performed, and some products are coated with ordinary rust-proof paint. Although this process can meet short-term usage needs, the lack of a long-term protective layer on the surface makes it prone to direct contact with air and moisture.

Galvanized finned tubes add a hot-dip galvanizing process to the steel finned tubes: the formed carbon steel finned tubes are immersed in molten zinc (at a temperature of about 450°C), forming a galvanized layer with a thickness of 85-120μm on the surface of the tube body and fins. The zinc layer forms a metallurgical bond with the base material, providing much stronger adhesion than ordinary coatings. This process difference directly sets the core distinction in corrosion resistance between the two products — the galvanized layer provides active protection through the "sacrificial anode protection method," while the rust-proof paint on steel finned tubes only offers passive isolation and is prone to chipping and failure.

II. Core Performance: Significant Differences in Corrosion Resistance and Durability

Corrosion resistance is the biggest gap between the two types of finned tubes. In humid environments with a humidity of over 60%, if steel finned tubes are not maintained in a timely manner, they typically show obvious rust within 3-5 years: red rust spots appear on the surface of the tube body, and the fins become loose due to corrosion, leading to a 15%-20% decrease in heat dissipation efficiency. If used in coastal areas with high salt fog or industrial dust environments, the rusting rate will further accelerate, and the service life may be reduced to 2 years.

Galvanized finned tubes, on the other hand, exhibit strong corrosion resistance. In the same humid environment, the galvanized layer can extend the rust incubation period to over 10 years. Even if the surface is scratched, the zinc layer will oxidize first, protecting the carbon steel base material from corrosion. Application data from a vegetable greenhouse in a coastal area shows that a heating system using galvanized finned tubes had no obvious rust within 5 years, with only a 3% decline in heat dissipation efficiency. In contrast, steel finned tubes installed during the same period had extensive rust and required the replacement of 30% of the pipes to maintain normal operation.

In terms of durability and heat dissipation stability, steel finned tubes suffer from rust problems, leading to scale buildup inside the tubes and fin detachment outside over long-term use, resulting in an annual heat dissipation efficiency decline of 5%-8%. The galvanized layer on galvanized finned tubes not only prevents corrosion but also reduces scale adhesion inside the tubes (the smooth zinc layer surface makes it difficult for scale to deposit), with an annual heat dissipation efficiency decline of only 1%-2%. The combination of fins and tube body is more stable and less prone to loosening due to corrosion.

III. Application Scenarios: Environmental Needs Determine Suitability

The suitability of the two types of finned tubes is entirely based on corrosion resistance requirements:

• Steel finned tubes are more suitable for dry, non-corrosive indoor scenarios, such as ordinary residential heating in winter (indoor humidity 40%-50%) and dry machine processing workshops (no dust, no moisture). In these scenarios, steel finned tubes can meet the usage needs for 5-8 years with annual painting maintenance, and the initial cost is lower, making them suitable for projects with limited budgets and stable environments.
• Galvanized finned tubes are the preferred choice for humid and corrosive environments, such as agricultural greenhouses (humidity 70%-85%), food processing workshops (high humidity due to frequent cleaning), coastal buildings (high salt fog), and chemical warehouses (small amounts of corrosive gases). Additionally, for scenarios where frequent maintenance is inconvenient (such as heating pipes installed at high altitudes in industrial plants), the low-maintenance characteristics of galvanized finned tubes can significantly reduce maintenance costs.

IV. Economic Cost: Balancing Short-term Investment and Long-term Benefits

In terms of initial investment, galvanized finned tubes are 15%-25% more expensive than steel finned tubes, leading some budget-sensitive projects to prefer steel finned tubes.

However, from a full lifecycle cost perspective (initial investment + maintenance costs + replacement costs), galvanized finned tubes are more economical. Over a 10-year usage cycle: steel finned tubes require painting maintenance every 2-3 years, with each maintenance costing about 20% of the initial investment, and 50% of the pipes need to be replaced within 10 years, resulting in a total cost of about 2.5 times the initial investment. Galvanized finned tubes only require 2-3 simple cleanings within 10 years, with no need to replace pipes, resulting in a total cost of about 1.2 times the initial investment.