Naturally Ventilated Polyhouse: High-Yield GI Pipe Greenhouse Structure

A Naturally Ventilated Polyhouse (NVPH) is a protected cultivation structure covered with UV-stabilized polyethylene film and designed with top and side ventilation openings. It works on the principle of natural airflow — hot air rises and exits through roof vents, while fresh air enters through side vents. This creates a balanced microclimate inside the structure without relying heavily on mechanical cooling systems. NVPH structures are widely used in India for high-value vegetable and flower cultivation due to their cost-effectiveness and energy efficiency.

The cost of an NVPH Polyhouse in India generally ranges between ₹700 to ₹1,200 per square meter depending on factors such as structural design, height, film thickness, wind load capacity, and location. The final price also varies based on optional systems like drip irrigation, fogging, insect netting, and foundation type. Farmers can significantly reduce their investment cost by availing government subsidies under horticulture schemes.

Yes, NVPH Polyhouses constructed as per the technical standards of the National Horticulture Board(NHB) and Mission for Integrated Development of Horticulture (MIDH) are eligible for government subsidy, subject to state approval and compliance verification. The structure must meet prescribed specifications such as HDG steel pipe thickness, micron zinc coating, approved design dimensions, and UV film standards. Subsidy percentage varies by state and farmer category.

An NVPH Polyhouse is ideal for cultivating high-value and off-season crops such as Capsicum, Tomato, Cucumber, Strawberry, Gerbera, Rose, and leafy vegetables. It is particularly beneficial for crops that require controlled temperature and humidity conditions. The structure enhances yield, improves quality, and allows farmers to supply produce during off-season periods when market prices are higher.

An NVPH Polyhouse is ideal for cultivating high-value and off-season crops such as Capsicum, Tomato, Cucumber, Strawberry, Gerbera, Rose, and leafy vegetables. It is particularly beneficial for crops that require controlled temperature and humidity conditions. The structure enhances yield, improves quality, and allows farmers to supply produce during off-season periods when market prices are higher.

A well-constructed NVPH Polyhouse made with Hot-Dip Galvanized (HDG) steel typically lasts 15–20 years due to its corrosion-resistant properties. The polyethylene film covering generally has a lifespan of 3–5 years depending on UV quality and maintenance. Proper installation and periodic inspection significantly extend the overall life of the structure.

The main difference lies in environmental control. An NVPH Polyhouse uses UV-stabilized plastic film to create a semi-controlled microclimate, making it suitable for high-value vegetable and flower cultivation. A Shade Net House uses HDPE shade net fabric primarily to reduce sunlight intensity and is commonly used for nurseries and low-cost cultivation. NVPH provides better protection against rain, pests, and extreme weather conditions compared to a Shade Net House.

An NVPH Polyhouse designed as per government-approved structural calculations can withstand region-specific wind loads. The structure includes proper foundation anchoring, arch spacing, and HDG steel framework to ensure stability. Wind resistance depends on design specifications and agro-climatic zone classification.

Basic NVPH structures rely on natural ventilation and do not require continuous electricity for cooling. However, optional systems such as drip irrigation pumps, fogging systems, and automated controls may require power depending on the farmer’s setup.

NVPH Polyhouses generally use 200 micron UV-stabilized polyethylene film as per government guidelines. This thickness ensures durability, high light transmission, and resistance against harsh sunlight and weather conditions. The film also helps maintain internal temperature and humidity levels suitable for high-value crop production.

NVPH Polyhouses generally use 200 micron UV-stabilized polyethylene film as per government guidelines. This thickness ensures durability, high light transmission, and resistance against harsh sunlight and weather conditions. The film also helps maintain internal temperature and humidity levels suitable for high-value crop production.

Income from an NVPH Polyhouse depends on crop selection, market demand, and management practices. High-value crops like capsicum, cucumber, and gerbera flowers can generate significantly higher returns compared to open-field farming. With proper crop planning and market linkage, farmers can achieve better yield per square meter and improved profitability through off-season cultivation.

Installation time for an NVPH Polyhouse generally ranges from 20 to 45 days depending on the project size, foundation type, and site conditions. Proper land leveling, foundation work, and structural assembly are crucial to ensure long-term durability and compliance with subsidy inspection norms.