STORM LAKE, Iowa – Iowa State University agricultural engineers are studying the use of a drainage water system as a sustainable and cost-effective solution to cool livestock facilities in the summer.

“The idea came to me last year during a heat wave,” Kris Kohl, ISU field agricultural engineer, based in northwest Iowa, told Farm World. “One of our poultry producers talked about losing about 25,000 turkeys in a three-week period. The high temperatures were about 100 degrees, but the low temperature at night was around 90 degrees, which means that’s what the dew point is.”

In Iowa, he said, “We are in the center of a continent where we get very cold winters and very hot summers. On average, it is about right. So how can we store the cold in January so that we could use it in July? Livestock buildings often require efficient cooling systems to ensure the well-being and productivity of the animals.

“However, traditional cooling methods like air-conditioning can be costly, and may have a significant cost for just a few weeks when the nighttime lows are still too high,” he added.

He said poultry and hogs can’t sweat, which makes them more susceptible to heat stress.

“We can mist them, but this only works if the dew point temperature is low,” he said. “All of the ventilation work we do for livestock, we try to give them a wind chill effect by blowing more air across them. But that only works when the temperature of the air is colder than body temperature. Almost all livestock have temperatures close to humans of 100 degrees.

“Heat waves are short-lived,” he added. “Once it gets beyond extreme weather, there is nothing they (livestock) can do to cool down.”  

He said this drainage water system, which is only in the beginning stages, will involve the collection and circulation of drainage water through a network of pipes installed within the livestock buildings.

“The collected water from the field drainage tile will be pumped through the livestock building, absorbing the heat from the building and then be discharged into a warm tile 60 feet away from the cold tile,” he said. “The water will flow through the soil to cool before being recirculated.”

He added the drainage water system would require about a 150-gallon flow per minute to bring the livestock building’s temperature down to 80 degrees.

“We are measuring the temperature of the water going in and coming out,” he said. “We are taking heat from the building and putting it back into the soil.” He added he and the research team are looking for the water to come out of the soil at 60 to 70 degrees.

He said utilizing drainage water as a cooling agent significantly reduces the operational costs associated with traditional cooling systems, while remaining sustainable: “By reusing drainage water, the system reduces water waste and minimizes the environmental impact of livestock farming.

“The system requires minimal energy input, compared to conventional cooling systems, resulting in reduced energy consumption and lower carbon emissions,” he said.

He added, “Maintaining optimal temperatures within the livestock buildings creates a comfortable environment for the animals, leading to improved welfare and increased productivity.”

Moreover, he said, “By using drainage water, the system contributes to efficient water management on the farm, reducing the need for additional water sources.”

He said some of the components of the project include developing a detailed design plan for the system, including the layout of pipes, heat exchange units and circulation mechanisms, as well as installing the necessary infrastructure, such as pipes, pumps and heat exchange units, according to the design plan.

Kohl said the research project will help to determine the feasibility of this system to prevent heat-related livestock losses that typically occur in late July.

He added he and the research team are looking at funding a building for the project: “That would be the next step: funding a full-blown building. Once we have funding, it (the project) would be on a private farm.”

Kohl said the system would have to be tested to ensure optimal performance and make any necessary adjustments for maximum efficiency, which include implementing a monitoring system to track the performance of the cooling system, and scheduling regular maintenance to ensure its continued efficiency.

“Using drainage water to cool livestock buildings offers a sustainable and cost-effective solution to the challenges of maintaining optimal temperatures for livestock,” he said. “By implementing this system, farms can reduce their environmental impact, lower operational costs, and improve the well-being and productivity of their animals.

“Iowa State University looks forward to reporting on how this new concept can provide comfort to livestock during the dog days of summer,” he added.