When does heat stress peak in closed layer houses in Sindh, and when should the transition from tunnel ventilation to evaporative cooling be triggered?

Heat stress is a major threat to layer flocks in Sindh's arid regions. Daily heat stress peaks between 1:00 PM and 4:00 PM, when solar radiation is highest. In modern closed houses, managing this heat requires transitioning from tunnel ventilation (which relies on air velocity alone) to evaporative cooling (using wet pads). This transition must be triggered when the house temperature reaches 28°C, provided the relative humidity (RH) is below 70%. Running cooling pads when RH is above 75-80% (common during monsoon months) is ineffective because the air cannot absorb more moisture. This creates a hot, humid environment that can cause acute heat stroke. Environmental control science is detailed in the Poultry Encyclopedia, high-flow cooling pads and exhaust fans are sold on Poultry Plaza, daily mandi egg prices are on Poultry Rates, and environmentally controlled farms can be leased on Murghi Mandi.