By ANDREA VARGO
Natural ventilation systems, rather that artificial systems, are the latest thing for livestock barns, said David Raisanen, president of Raydot, Inc. of Cokato.
These systems are better for the livestock, are computer-controlled, and have an advantage of low electrical costs, he said.
Lots of hog finishing barns all over the midwest, including Missouri and Iowa, have Raydot systems. These barns house 500 to 1,000 animals, said Raisanen.
The Fitzsimmons farm north of Cokato has one of Raydot's computerized systems that controls the environment for farrowing sows.
These natural ventilation systems provide an environment that the employees prefer, also.
The system starts with a three-foot concrete sidewall, topped with plastic, insulated curtains that roll up or down, according to the computer commands.
There is a chimney on the top of the barn with a cap.
The interior and exterior of the barn are mapped for the computer, he said.
Monitors are placed at intervals, both inside and outside the building.
The computer system can detect temperature, humidity, cold drafts, stagnant air, airborne bacteria, and particulates.
These systems can also consider animal body weight to measure heat loss or gain.
After taking all these things into consideration, the computer can then adjust ventilation, heating, or misting for animal comfort.
In a power-ventilated barn, fans and heaters might adjust the environment.
In a naturally ventilated barn, the computer would tell the sidewall curtains to go up or down, as well as open and close the ridgevents.
With at least two separate curtain systems on each wall, the computer can make small adjustments in ventilation, allow for external breezes and wind directions, and keep the temperature and humidity stable without drafts.
The air comes in on the sides and exits out the ridgevents, creating a natural chimney effect.
The computer also keeps historical data for printed reports.
A telephone modem can even let the barn operator monitor the facility from off the site.
One of the nice advantages of the natural ventilation system that uses the curtains is the amount of natural light that comes in the barn.
The atmosphere is just better for animals and employees, he said.
Technology has finally caught up with ideas, said Raisanen.
Raydot added a wind tunnel test chamber in 1995, and this state-of-the-art system has allowed the company to test air movement and enhance product efficiency and performance of its products.
"It's also a great place to cool off on a really hot day, but that's supposed to be an engineering department secret," Raisanen said.
Raisanen started Raydot with his father, who was the head engineer at Lester's in Lester Prairie.
"We still don't do a lot of work in Minnesota, because the farm numbers are dwindling," he said.
The majority of the big confinement operations Raydot works with are in Iowa, Oklahoma, Kansas, Missouri, and South Dakota.
"We need to be conscientious about where we place those farms," said Raisanen.
"We need to talk to the neighbors and be political, so to speak," he said.
The company employs 64 people, and does assembly work. It also does some of the raw manufacturing, but outsources fiberglass work.
The building will be expanding to 45,000 square feet with a new office and service technician areas.