Floating Gardens in Mindoro, Wis., uses aquaponics

Down on the farm: Aquaponics operation thrives with heating system

July 13, 2017
Aquaponics combines aquaculture, or fish farming, and hydroponics in a closed-loop system. Hydronic heating provided the control needed to regulate the heat in the greenhouse.

MINDORO, WIS. — First off, what the heck is aquaponics, you ask? It’s a cycle of life, really. Waste from farmed fish provides nutrients for plants grown hydroponically — raising plants in water without soil — which, in turn, purifies the water. In essence, aquaponics combines aquaculture, or fish farming, and hydroponics in a closed-loop system. The nutrient-rich water that results from raising fish provides a source of natural fertilizer for the growing plants.

That’s the case for the Goodenough’s, a third-generation farm family from the small town in western Wisconsin. The move to aquaponics was precipitated several years ago, when according to Tim Goodenough, “input prices were high, grain prices were fluctuating constantly and Mother Nature was throwing us curve balls.”

From Ag to Aq

In 2014, Tim, his wife Bonny and four children, disassembled a 13,600-sq.ft. greenhouse and spent the next three months dismantling and transporting it piece by piece. The following year, the Goodenough family finalized construction plans for the greenhouse and the attached lean-to building that was to house the mechanical system.

The reconstruction of the greenhouse began in 2016. The Goodenough’s worked with construction crews for six months, at which time they hired Ron Hammes Refrigeration, a residential and commercial HVAC company based in La Crosse, Wisconsin, to handle installation of the heating equipment and piping. Moving from hogs and cows — and later to a corn and soybean operation — to aquaponics, the Goodenough’s needed to protect their investment with an advanced building control featuring Weil-McLain boilers.

Mimicking longest day of the year

The aquaponics project, said Bonny Goodenough, needed a more controlled environment for farming. “We required air temperatures of about 70 degrees in the greenhouse year-round and water temperatures between 70 to 75 degrees for the fish and plants to thrive,” said Bonny Goodenough.

With the 13,000-sq.ft. greenhouse and attached lean-to ready for operation in November, and the wintry Wisconsin weather setting in, according to Tim Goodenough, it was imperative to get the heating system online as soon as possible. The greenhouse structure, which consists of lightweight polycarbonate, could collapse under the weight of a heavy snowfall.

“There is no structural strength to the building so snow is a concern, and it needs to be melted as soon as possible,” said James Hammes, co-owner, Ron Hammes Refigeration.

Alleviating that concern, the boilers also allowed the greenhouse to stay snow free all winter.

“We had some major snowfalls this last season, but it always melted and never accumulated on the roof of the greenhouse,” said Tim Goodenough.

To meet project parameters, Hammes recommended the installation of four 399 MBH Weil-McLain Evergreen boilers with primary-secondary pumping in a multiple boiler system. In this configuration, a master boiler controls the modulation and sequencing of boilers on the network to achieve the desired system supply temperature. The entire greenhouse is then heated through Modine fan coil units.

Instead of installing a possible six to seven boilers for the project, said Hammes, four 400,000 Btu Evergreen boilers are staged and tied together through Weil-McLain controls, which facilitate up-and-down modulation.

“With the automatic sequencing feature, the boilers communicate directly with one another, so they sequence themselves and rotate as needed,” said Hammes. “They operate to optimize energy use and efficiencies. When heat is required, the boilers will stage on one-by-one as needed.”

The Evergreen units were tied to existing heat exchangers on site and installed as part of a Wadsworth system, a building control solution that monitors external temperature, wind speed and direction, precipitation and humidity, and also internal factors such as temperature and humidity.

To maintain conditions, the advanced Wadsworth system cycles the boilers, heat exchangers and grow lights on and off, and opens and closes vents and shade cloth based on the amount of sunlight from the sun. It is designed to keep humidity and temperature levels inside the grow operation at targeted parameters.

“We are essentially trying to create the longest summer day of the season year round in the greenhouse,” said Tim Goodenough. “The vents, lights and shade cloth are all computerized and move automatically to maintain conditions.”

Heating success story

According to Tim Goodenough, the installation of the Weil-McLain boilers went smoothly, and the family’s Floating Gardens LLC aquaponics farm operation is already a success. The four Evergreen boilers maintain proper temperatures in the building, while providing supplemental heat for the fish tanks and nurseries.

“The boilers are very energy efficient and will cycle on and off as needed,” said Tim Goodenough. “They typically shut off when the temperature outside is 65 degrees and higher.”

With the heating system in place, the nursery was filled in early December with 130 tilapia and several varieties of vegetables. When all tanks are filled, they will hold approximately 2,300 fish, and the Goodenoughs are producing approximately 250 heads of lettuce a day with varieties of romaine, butterhead and summer crisp. The family also is growing other produce such as swiss chard, peapods, string beans, kale, tomatoes and radishes.

The Goodenough’s sell their products at their on-site market, and to farmers markets, local restaurants, schools and grocery stores.  

“We believe aquaponics is the new face of farming as it is sustainable, healthier and can supply more food per acre than traditional methods,” said Tim Goodenough. “We are very happy with the system we have in place, and the Weil-McLain boilers are a key component in making this efficient growing method a success.”

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