In greenhouse cultivation, maintaining warmth during winter, ensuring constant temperature during seedling propagation, and precise temperature control during critical crop growth stages are essential to securing yield and quality. High-frequency welded galvanized finned tubes, valued for their "high-efficiency heat transfer, corrosion resistance in humid environments, and cost-effective durability," have become the ideal choice for greenhouse climate control systems.

These finned tubes combine a hot-dip galvanized protective layer with an optimized fin structure to deliver reliable performance in the high-humidity, fog-prone conditions typical of greenhouses. They provide a stable thermal environment for vegetables, flowers, fruit trees, and other crops, while meeting the economic demands of agricultural production—driving the shift toward more efficient and large-scale greenhouse farming.

Greenhouses require rapid temperature response. In winter, indoor temperatures must rise quickly from below 5°C to an optimal 15–25°C. During seedling stages, diurnal temperature fluctuations must be kept within ±5°C to prevent chilling injury or excessive stretching. The fin-enhanced heat dissipation design of hot-dip galvanized finned tubes effectively meets these needs.

The spiral-wound fins are tightly bonded to the galvanized base tube, increasing the effective heat exchange surface area by 5–7 times compared to bare pipes—significantly improving contact efficiency with greenhouse air. Meanwhile, the consistent thermal conductivity of the carbon steel base tube (~45 W/(m·K)) ensures rapid heat transfer from the internal medium (typically hot water or low-pressure steam) to the fins, which then release heat into the greenhouse via convection.

For example, in a vegetable greenhouse in northern China, spiral finned tubes with a 12 mm fin height and 5 mm pitch, heated by 85°C hot water, are evenly installed along both side walls and the central aisle in three rows. Within 30 minutes of startup, the internal temperature rises from an initial 4°C (with outdoor temperatures at -8°C) to a stable 18°C. Temperature distribution is highly uniform, with a variation of no more than ±1.5°C across the greenhouse—far superior to the ±3°C variation commonly seen with traditional coal-fired warm air furnaces.

In a strawberry nursery greenhouse, galvanized finned tubes equipped with thermostatic control valves precisely regulate heat output, maintaining the seedling zone at a steady 22±1°C. As a result, germination rates improve from 85% under conventional heating to 98%, seedlings grow more uniformly, and the incidence of pests and diseases drops by 12%. This high-efficiency thermal performance enables greenhouses to respond swiftly to external temperature fluctuations, creating a stable "microclimate" for optimal crop development.

Greenhouses typically maintain high relative humidity (70%–95%), with frequent irrigation and misting further exacerbating moisture levels. Ordinary carbon steel finned tubes are prone to rust, reducing heat transfer efficiency and risking contamination of soil and crops from flaking rust particles.

Hot-dip galvanized finned tubes solve this issue at the source. Both the base tube and fins are coated with a 80–120μm thick zinc layer, which reacts with oxygen and moisture in the air to form a dense, protective zinc oxide film that prevents direct contact between the steel and corrosive agents. Additionally, zinc acts as a sacrificial anode—providing cathodic protection even if the coating is locally damaged—greatly extending service life.

In a flower greenhouse in southern China’s rainy region, flat finned tubes with hot-dip galvanized coating have operated continuously for six years. The fins and base tubes show no significant corrosion, only minor oxidation at connection points. Heat dissipation efficiency has declined by less than 5%, dramatically outperforming non-galvanized carbon steel tubes, which degrade at a rate of approximately 15% per year. Comparative tests show that non-galvanized tubes develop perforations due to rust after just three years and require full replacement, whereas galvanized tubes need only annual dust cleaning to maintain peak performance.

Moreover, the non-toxic, environmentally friendly zinc coating poses no risk of heavy metal contamination, making it suitable for organic vegetable and green-certified flower production, ensuring food safety and product quality.

Greenhouses vary widely in design—single-span arches, multi-span glasshouses, solar greenhouses—and spatial constraints from crop rows, irrigation lines, and ventilation systems demand flexible, robust heating solutions. Hot-dip galvanized finned tubes meet these challenges through a modular and lightweight design.

Tubes can be custom-cut to length (typically 2–8 meters), and weigh 30% less than equivalent stainless-steel units, enabling easy manual handling and installation without heavy lifting equipment. Connection methods such as flanges or quick couplings eliminate the need for on-site welding, improving installation efficiency by up to 50% compared to welded systems. If crop layouts change, the system can be quickly disassembled and reconfigured.

In a multi-span tomato greenhouse, finned tubes are suspended from roof trusses, positioned 50–80 cm above the crop canopy. This layout saves valuable growing space while ensuring even downward heat distribution, avoiding root damage from ground-level overheating. In solar greenhouses cultivating cucumbers, tubes are mounted vertically along the north-facing earthen wall, leveraging its thermal mass to minimize heat loss and improve energy efficiency.

In practice, galvanized finned tubes demonstrate far greater structural integrity than plastic alternatives, resisting airflow disturbances from ventilation fans and minor vibrations. Long-term operation shows no issues with fin detachment or pipe deformation, resulting in extremely low maintenance requirements.

With narrow profit margins in agriculture, both upfront investment and long-term operating costs are critical factors in equipment selection. Hot-dip galvanized finned tubes offer clear economic advantages.

Initial costs are only 1/2 to 2/3 that of stainless-steel equivalents. Installation is simple and fast. For a 1,000 m² multi-span greenhouse, using galvanized finned tubes reduces total system investment by 45,000 RMB compared to a stainless-steel alternative.

In terms of lifespan, galvanized finned tubes last 8–12 years under greenhouse conditions—over twice as long as untreated carbon steel tubes—reducing replacement frequency.

Operationally, they require no anti-corrosion treatments. Only 1–2 annual cleanings are needed, with maintenance costs amounting to less than 1% of the equipment’s total value per year—far below the ~3% annual cost for unpainted carbon steel tubes requiring regular repainting.

Data from a vegetable farming cooperative shows that switching to galvanized finned tubes reduced winter heating energy consumption (for hot water generation) by 20% compared to traditional coal-fired furnaces, saving approximately 18,000 RMB annually in fuel costs. The payback period for the entire system is just 1.2 years.

This combination of low cost and high return makes galvanized finned tubes the preferred choice for small farms and cooperatives, accelerating the adoption of advanced climate control technologies across the agricultural sector.

As facility agriculture moves toward larger scale and greater intelligence, demands for heating systems will grow—requiring higher efficiency, reliability, and environmental compatibility. Hot-dip galvanized finned tubes already meet core greenhouse needs and are fully compatible with smart control systems (e.g., integration with temperature sensors and solenoid valves for automated regulation).

Looking ahead, further enhancements—such as optimized fin geometries (e.g., serrated fins for improved turbulence and heat transfer) and advanced coatings (e.g., zinc-aluminum alloys for superior corrosion resistance)—will expand their application scope. These innovations will continue to support the transformation and high-quality development of modern agriculture.