Dealing with invisible forces is the norm when it comes to airflow and ventilation challenges in today’s hog barns.

A four-state collaborative effort, including South Dakota State Univer­sity (SDSU), Iowa State University, the University of Minnesota and the University of Nebraska, has been holding ventilation workshops to meet those challenges.

Steve Pohl and his agricultural engineering staff at SDSU in Brookings developed the original mobile ventilation laboratory six years ago, a small, wooden, somewhat cumbersome trailer. The lab had to be hoisted up and onto a trailer for transport around the Midwest. Now it is being replaced with a more versatile version.

“This mobile lab is bigger and has a lot more capabilities,” Pohl explains. It features an aluminum skin and sprayed-on foam insulation made from soybeans, and is based on a design used for fish houses. Like a fish house, it can be raised and lowered using a crank.

“We wanted to be able to simply raise it up using a crank on the side, and hook it up to a trailer for transport,” he says. “The Lodge, a specialty company in Brookings, modified the trailer so we could do that.”

In addition, the new lab has more capability to test and teach how to manage soffits. “That is a challenging problem with swine barns. Soffits represent the first point of entry of air into the attic space, which can create a pressure point that blocks proper airflow coming into a barn, and reduces fan performance as static pressure increases,” he continues. Hot-weather ventilation, such as during the summer of 2010, has made this a critical challenge.

Further, rising static pressure places more pressure on the fans, which limits the cubic feet of air that moves into a barn and then is exhausted, Pohl points out.

“So one of our main goals is to train producers to understand what the airspeed of the inlets should be. We shoot for 800 to 1,000 ft./minute,” he comments.

The basics of air movement inside hog barns and troubleshooting systems are covered in the Midwest ventilation workshops. Basics include a look at fans, inlets and controls. Troubleshooting addresses problems with automatic ventilation controllers, which may have been installed incorrectly by the manufacturer or an equipment installer, Pohl says.

“Overall, the pork industry is getting better when it comes to knowledge and understanding of ventilation, but we still need to work on fine-tuning ventilation systems,” Pohl says. “Every barn is different, every controller is somewhat different. It’s just a matter of matching everything and making sure everything works.”

Adding to the challenge is the frequent turnover of staff in large production systems, he notes.

Ventilation Workshops

Pohl estimates about 75 workshops have been conducted in the past six years, attended by more than 1,000 producers.

This fall, the four-state group will announce another round of producer workshops using the new ventilation lab. Sessions run all day, starting in the morning with the basics of the environment and ventilation systems and the needs of the pigs. In the afternoon, producers split up into hands-on groups and discuss troubleshooting issues.

Producers in the four-state area will also be able to see the new mobile lab at state pork shows this winter, where the basics of hog barn ventilation will be demonstrated.

The Iowa Pork Producers Association and the Minnesota Pork Board were major contributors in funding for the trailer. Automated Production Systems was a major donor of equipment for the trailer.