What Are the Advantages and Disadvantages of Greenhouse Galvanized Spiral Fin Tubes?

What Are the Advantages and Disadvantages of Greenhouse Galvanized Spiral Fin Tubes?

As a commonly used heat dissipation device in greenhouses, greenhouse galvanized spiral fin tubes have significant performance advantages, but they also have certain limitations in specific scenarios. The following is a detailed analysis from the advantages, disadvantages, and comparison:

I. Core advantages of greenhouse galvanized spiral fin tubes

1. Efficient heat dissipation, dual functions of heating and cooling

Large heat dissipation area: The circular wing-shaped fins are evenly distributed around the base tube in a ring shape, which is 3-5 times higher than the heat dissipation area of ​​ordinary light tubes. The heat conduction efficiency is high, which can quickly increase the temperature in the greenhouse (heating in winter) or assist in the discharge of waste heat (ventilation and cooling in summer).

Fast thermal response: The fins and the base tube are tightly connected by high-frequency welding, with low thermal resistance. When the temperature of the heat medium (hot water/steam) changes, the surface temperature of the fins can be quickly synchronized, which is suitable for scenes that require frequent temperature control (such as day and night temperature difference control in the seedling shed).

2. Strong corrosion resistance and adaptability to complex environments

Hot-dip galvanizing process: The inside and outside of the tube are hot-dip galvanized, and a dense zinc layer (thickness ≥ 85μm) is formed on the surface, which can resist corrosive factors such as high humidity, fertilizer volatilization (such as ammonia), and irrigation water vapor in the greenhouse. The service life can reach 15-20 Anos, far exceeding ordinary steel pipes (5-8 years easy to rust).

Acid and alkali resistance: The galvanized layer has good tolerance to weak acidic/alkaline environments (such as soil volatiles in vegetable greenhouses) and is suitable for long-term high-humidity working environments (such as aquarium breeding sheds and edible fungus greenhouses).

3. Flexible installation and low maintenance cost

Modular design: Single-tube or multi-tube parallel combination can be customized according to the size of the greenhouse, supporting vertical and horizontal installation, and adapting to different shed types (such as arch sheds and multi-span greenhouses).

Low maintenance requirements: The fin surface is smooth and not easy to accumulate dust. It only needs to check the sealing of the pipeline interface daily, and no frequent cleaning is required; the welding structure is firm, the fins are not easy to fall off, and the frequency of manual maintenance is reduced.

4. Accurate temperature control and outstanding energy saving

Flexible temperature control: The heat medium flow can be adjusted through the valve, or an automatic temperature control system (such as electric regulating valve + temperature sensor) can be installed to achieve accurate temperature control of ±1℃ and avoid energy waste (such as automatically increasing heating during low temperature periods at night and reducing flow during sufficient light during the day).

Significant energy saving effect: Under the same heating area, it saves 10%-20% energy consumption compared with traditional light tubes; when combined with clean energy such as heat pumps and solar energy, the comprehensive energy saving rate can reach more than 30%.

5. Stable structure, adaptable to complex loads

High strength of base pipe: Seamless steel pipe or thick-walled welded pipe is used, with strong pressure bearing capacity (working pressure can reach 1.0-1.6MPa), suitable for steam heating or high-pressure hot water circulation system.

Good anti-vibration performance: The fins are firmly welded to the base pipe, and are not easily damaged in vibration environments such as fan ventilation and livestock and poultry activities. It is suitable for livestock and poultry breeding sheds (such as pig houses and chicken houses).

II. Main Disadvantages of Galvanized Spiral Finned Tubes for Greenhouses

1. High initial investment cost

Material and process cost: Circular wing-shaped finned tubes require special molds to roll fins, and the welding process is complicated. The unit cost is 30%-50% higher than that of ordinary light tubes; galvanizing also increases the surface treatment cost.

Installation cost: The multi-tube parallel system needs to be equipped with accessories such as manifolds and temperature control valves, and the overall cost is higher than that of simple light tube heat dissipation systems (such as single-tube hot water circulation).

2. There are certain requirements for installation space

Tube diameter and fin size: The outer diameter of the circular wing-shaped finned tube is larger (common specifications DN50-DN100, the outer diameter of the fin can reach 100-150mm), and sufficient installation space needs to be reserved. It is not suitable for low greenhouses or small space greenhouses with a height of less than 2 meters.

Pipeline layout restrictions: When multiple tubes are connected in parallel, they need to be arranged horizontally or vertically, which may occupy part of the planting/breeding area (such as the pipelines in the livestock and poultry house need to be installed overhead to avoid animal collisions).

3. The cooling efficiency in summer is limited and needs to be coordinated with other equipment

Passive heat dissipation depends on ventilation: When the temperature is high in summer, the fin tube can only dissipate heat through natural convection of air or forced ventilation by fans. If the outside temperature is close to the temperature in the shed, the heat dissipation efficiency will drop significantly, and it needs to be coordinated with cooling systems such as wet curtains and sprays.

Unable to actively cool: The fin tube itself has no cooling function and needs to be connected to external cooling equipment such as chillers (the cost is further increased). Compared with dedicated evaporative cooling equipment (such as air coolers), the cost performance is relatively low.

4. Dust accumulation on the fins affects long-term performance

Maintenance requirements in high dust environments: In livestock and poultry breeding sheds (such as broiler houses, rabbit houses) or areas with strong winds and sand, dust is easily accumulated in the gaps between the fins. If it is not cleaned for a long time, a “thermal resistance layer” will be formed, resulting in a decrease in heat dissipation efficiency (when the annual dust accumulation exceeds 2mm, the heat dissipation efficiency may decrease by 15%-20%).

Difficulty of cleaning: The fins are densely arranged in a ring shape, which is difficult to wipe manually. A special high-pressure air gun or vacuum cleaner is required to clean it, which increases maintenance costs.

5. Heavy weight, and requirements for greenhouse load-bearing capacity

Influence of steel weight: A single DN80 round wing fin tube (length 6 meters) weighs about 25-30kg. When multiple tubes are combined, the total weight is large. It is necessary to ensure that the greenhouse frame (such as steel tube trusses, bamboo and wood supports) has sufficient load-bearing capacity to avoid the risk of collapse (especially bamboo and wood greenhouses need to be reinforced in advance).