A simple, water-based technology is helping Pakistani farmers protect their flocks from deadly heatwaves, ensuring both animal welfare and food security.
Imagine being trapped in a thick winter coat during a relentless 45°C heatwave with no way to cool down. This is the everyday reality for millions of broiler chickens in Pakistan during the scorching summer months. Unlike humans, poultry birds lack sweat glands, making them extraordinarily vulnerable to heat stress. Conventional air-conditioning is prohibitively expensive, while traditional swamp coolers often fail when needed most. Now, innovative evaporative cooling technologies are emerging as a lifeline for Pakistan's vital poultry industry, offering a sustainable and economical solution to an age-old problem.
The vulnerability of poultry birds to high temperatures stems from their fundamental biology. As explained by researchers studying thermal comfort in poultry, "broilers lack sweat glands as compared to humans and undergo panting process to mitigate their latent heat (moisture produced in the body) in the air"2 .
This panting process is the bird's primary defense against overheating, but it becomes ineffective when humidity rises too high, creating a suffocating situation where heat dissipation fails1 2 .
Once environmental temperatures approach 47°C, the consequences can be fatal for the birds1 .
47°C
Environmental temperatures approaching this level can be fatal for poultry birds1 .
Pakistani researchers have focused on three main evaporative cooling systems, each with distinct advantages:
A more advanced system that cools air without adding moisture through heat exchange. "The working air is cooled isenthalpically like DEC, and the cooling effect is transferred to product air by heat transfer between wet and dry channels"4 .
Researchers conducted detailed experiments to evaluate these three cooling systems specifically for the climatic conditions of Multan, Pakistan—a region known for its extreme summer heat1 2 .
The research team developed lab-scale experimental versions of all three EC systems with similar housing assemblies for comparable results. Each system contained:
The systems were tested under various conditions, with data collected specifically for Multan's climate, which features hot, dry conditions for most of the year followed by a humid monsoon season1 .
The experimental results revealed significant differences in performance among the three systems, with the MEC system consistently outperforming the others, particularly during the pre-monsoon extreme heat period1 2 .
| Cooling System | April-June Temperature Drop (°C) | July-September Temperature Drop (°C) |
|---|---|---|
| DEC | 7-10 | 5.5-7 |
| IEC | 5-6.5 | 3.5-4.5 |
| MEC | 9.5-12 | 7-7.5 |
The MEC system's superior performance is attributed to its innovative design that enables "dew-point cooling"—the ability to cool air beyond the limitations of conventional evaporative systems2 . This breakthrough allows it to achieve greater temperature reductions without adding excessive moisture to the air.
| Cooling System | THI Reduction (°C) |
|---|---|
| DEC | 3.5-9 |
| IEC | 3-7 |
| MEC | 5.5-10 |
The THI reduction is perhaps even more important than temperature reduction alone, as it accounts for the combined effect of heat and humidity that determines poultry thermal comfort2 .
| Component | Function | Specifics Used in Experiments |
|---|---|---|
| Heat/Mass Exchanger | Core cooling component | Separate dry and wet channels for IEC/MEC; cellulose pads for DEC |
| Temperature & Humidity Sensors | Environmental monitoring | Precision sensors for ambient and supply air conditions |
| Air Velocity Sensors | Airflow measurement | Monitoring ventilation rates critical for poultry comfort |
| Water Circulation System | Provides evaporation source | Storage tanks and distribution systems |
| Fan Assembly | Creates air movement | Ensures proper airflow through cooling media and into poultry space |
| Data Acquisition System | Records performance metrics | Collects and analyzes temperature, humidity, and velocity data |
The implications of this research extend far beyond immediate poultry welfare. With the poultry sector contributing approximately 1.4% to Pakistan's GDP and producing nearly 1.47 million tons of poultry meat annually, heat stress represents a significant economic threat1 .
EC systems consume significantly less electricity compared to conventional compressor-based AC systems, making them more affordable to operate and reducing strain on Pakistan's energy grid4 .
For a developing economy like Pakistan, the low-cost and environmentally friendly nature of these improved systems makes them accessible to more farmers, helping to secure livelihoods and maintain food production2 .
While evaporative cooling systems have limitations during humid conditions, ongoing research continues to enhance their effectiveness. The integration of solar-powered systems and smart monitoring technologies represents the next frontier in sustainable poultry cooling5 8 .
Advanced evaporative cooling (DEC, IEC, MEC) providing effective temperature reduction in dry conditions.
Integration with solar power to reduce energy costs and increase accessibility in remote areas.
Hybrid systems combining evaporative cooling with other technologies to maintain effectiveness during humid periods.