Identity

A passive atmospheric structure designed to maintain basic microclimatic conditions using natural environmental forces. Driven strictly by thermodynamic principles, its performance is governed by wind-induced pressure differences and buoyancy-induced thermal forces, commonly known as the chimney effect.

Overview

The Naturally Ventilated Shed is an open-sided housing design that is widely dominant in traditional Indian poultry farms. It is a low-cost structure that utilizes natural wind currents for cross-ventilation. While highly economical and suitable for moderate climates, it carries a severe risk of heat stress during the summer months due to its reliance on unpredictable external ambient conditions.

Structured Facts

Classification

Passive Atmospheric System / Naturally Ventilated Housing.

Purpose

To maintain basic microclimatic conditions using natural environmental forces and wind currents without the use of high-capacity mechanical exhaust fans.

Design & Construction

Designed strictly under the Bureau of Indian Standards (BIS) code of practice, IS 2732:1985. The structure is constructed with a standard width of 7.5 to 9.0 meters and a longitudinal length of 18.0 meters (excluding wall thickness) or 18.4 meters (including wall thickness). Vertical elevations require a minimum eave height of 2.0 meters and a central ridge height of 3.0 meters. Longitudinal sidewalls consist of a solid concrete or brick masonry foundation half-wall extending 60 to 66 centimeters above the floor level. The remaining 1.33-meter vertical opening is fitted with galvanized mild steel wire netting (1 mm diameter, 12 x 12 mm or 2.5 x 2.5 cm aperture, 16-gauge). The floor consists of cement-concrete or brick-cement elevated at least 25 centimeters above the surrounding ground level. The roof features a gabled design with a layer of natural thatch over galvanized steel sheets in hot regions, requiring a lateral roof overhang of not less than 1.07 meters (3.5 feet).

Environmental Controls

• Ventilation: Natural cross-ventilation driven by wind-induced pressure differences and buoyancy-induced thermal forces (chimney effect).
• Air Speed: Dependent on ambient wind.

Capacity & Layout

The interior is partitioned into 10 separate compartments (each measuring 3.6 meters in length by 3.125 meters in width). These compartments are separated by a central longitudinal passage measuring 18.4 meters in length by 1.25 meters in width. Access is managed via main exterior doors (1.2 meters wide by 2.0 meters high) and pen-partition doors (0.6 meters wide by 1.8 meters high) raised 30 centimeters above the floor level.

Equipment Integration

Shed Roof Insulation.

Advantages

Highly economical and a low-cost structural design.

Limitations

Carries a high risk of heat stress during the summer months. Highly vulnerable to weather fluctuations, resulting in poor FCR and higher mortality during seasonal extremes. Farms utilizing this structure are often disqualified from minimum support price (MSP) guarantees in modern contract integration frameworks.

Biosecurity Features

The 16-gauge galvanized mild steel wire netting prevents predator entry while maximizing open surface area.

Quantitative Data

• Stocking Density: 2.4 sq ft (0.225 square meters) per heavy bird.
• Air Speed: Dependent on ambient wind.
• Floor Space: 2.4 sq ft (0.225 square meters) per heavy bird.
• Dimensions: Width: 7.5 m to 9.0 m. Length: 18.0 m to 18.4 m. Eave Height: 2.0 m. Ridge Height: 3.0 m. Lateral Overhang: 1.07 m.

Relationships

• Equipment: Shed Roof Insulation.
• Environmental Parameters: Wind-induced pressure, Buoyancy-induced thermal forces (chimney effect).
• Diseases: Heat Stress.
• Production Systems: Contract Integration Frameworks.