Poultry Shed Ventilation Guide: Exhaust Fans, Cooling Pads and Air Movement for Indian Farms

Indian summers are hard on livestock. When shed temperatures climb, broilers and layers pant, eat less and grow slower; egg production drops; and in extreme heat, mortality rises. Dairy cattle suffer too, with lower milk yield during heat stress. Good ventilation is the most cost-effective way to protect birds, animals and farm income. This guide explains the main ventilation methods and the equipment that makes them work.

Why ventilation matters in a poultry shed

A poultry shed has to get rid of three things continuously:

• Heat — from the sun on the roof and walls, and from the birds themselves.
• Moisture — from breathing, droppings and drinkers, which makes litter wet and raises humidity.
• Gases and dust — mainly ammonia from litter, which harms bird health and worker comfort.

Natural ventilation through curtains and side openings works in mild weather, but on hot, still days it simply cannot move enough air. That is when mechanical ventilation becomes essential.

1. Tunnel ventilation: the standard for hot weather

In tunnel ventilation, large exhaust fans are installed on one end wall of the shed and air inlets (often with cooling pads) on the opposite end. The fans pull air through the whole length of the house, creating a steady airflow over the birds. Moving air carries heat away from the birds' bodies, so they feel cooler than the thermometer reading suggests.

For tunnel ventilation to work well:

• Keep side curtains and gaps closed so that air enters only through the planned inlets.
• Size the total fan capacity to the volume of the shed and the number of birds.
• Make sure inlet area is large enough so fans are not "starved" of air.

2. Choosing exhaust fans for poultry and dairy sheds

Box-type exhaust fans with a self-closing shutter are the most common choice for farms. When selecting them, look at:

• Air volume at working pressure — larger fans move more air per unit of power.
• Construction — galvanized steel housings resist the corrosive, humid and ammonia-laden air inside sheds.
• Shutters — gravity or drop-hammer aluminium louvres close automatically when the fan stops, preventing back-draught.
• Safety guards — mesh on both faces protects birds and workers.
• Motor duty — continuous-duty motors are needed because fans may run day and night in summer.

For example, the Ayzair-1380 heavy-duty hammer exhaust fan (50 in / 1380 mm) moves 44,500 m³/h on a 1.1 kW three-phase motor, with a hot-dip galvanized cabinet, stainless steel impeller and drop-hammer shutter. The full Heavy Hammer exhaust fan range runs from 200 mm to 1750 mm, so smaller sheds and side walls can be covered as well.

3. Adding evaporative cooling

Air movement alone cannot lower the actual air temperature. In hot, dry weather, evaporative cooling pads at the tunnel inlet can bring the incoming air temperature down significantly as water evaporates from the pads. In very humid weather the benefit is smaller, so pads are usually switched off or run intermittently during the monsoon.

Where a full pad wall is not practical — for example in small sheds, hatcheries, feed rooms or dairy parlours — ductable evaporative air coolers can deliver cooled fresh air directly to the zone that needs it.

4. Air circulation for dairy sheds and open houses

Open-sided dairy sheds cannot be tunnel ventilated, but cattle still benefit greatly from moving air over the resting and feeding areas. Options include:

• HVLS (High Volume Low Speed) ceiling fans for large, high-roofed sheds — a single large fan covers a wide area quietly and with low power.
• Mobile industrial fans on wheels that can be moved to where animals gather.
• Combining fans with sprinklers or misters over feeding lanes in hot, dry periods.

5. Maintenance tips

• Clean fan blades, guards and shutters regularly — dust and feathers reduce airflow noticeably.
• Check belt tension on belt-driven fans and replace worn belts.
• Clean cooling pads and check water distribution before each summer.
• Keep a few spare fans or motors ready for peak season breakdowns.

Get the sizing right

The right number and size of fans depends on shed dimensions, roof height, bird count and local climate. Ayzair, a Pune-based manufacturer of exhaust fans, HVLS fans and evaporative coolers for poultry, dairy and industrial use, offers free ventilation sizing and quotations. Share your shed details at ayzair.com/contact.