Fruits of their labour: Cooling with Geoexchange

Fruits of their labour: Cooling with Geoexchange
Case Story: Gebbers Farms

Gebbers Farm harnesses the ground’s energy to produce fresher fruit and a greener planet

Keeping apples fresh and cool is a challenge for many farms, but it is one that Gebbers Farms solved in a unique way.

At its 9,290 square-meter facility on the Eastern slopes of the Cascade Mountain Range in Washington, USA, Gebbers sorts, processes and pre-sizes thousands of apples daily. The company revolutionised its field-to-table process in 2008 when 35-year HVAC veteran Doug Lockhart of Lockhart Industries installed a Geoexchange system.

A greener way forward

The system takes advantage of the earth’s naturally stable temperatures to cool the water and rooms used at the Gebbers facility. Geoexchange heat pumps are hooked up to a series of pipes in loops, which run through a large holding pond built at the site. Excess heat is transferred into the pond in summer and pulled from the pond in winter. In essence, it is the same heat-exchanging process used by a household heat pump.

“Gebbers Farms believes in taking a proactive approach to the responsible use of scarce natural resources,” says Bob Grandy, Gebbers’ spokesman and food safety engineer. “In our business, we use large quantities of water and electricity to process fruit. Fortunately, by being located where we are in North-Central Washington, we are blessed with both. Truthfully, it would have been easier and less expensive to go with a ‘conventional refrigeration system’ in the pre-size facility that we built in 2009, Instead, Gebbers chose Geoexchange.”

Bob Grandy explains that Gebbers actively seeks out new technologies for its production line, an example of which is its use of geothermal technology.

PHOTO: A Geoexchange system cools the water that keeps fruit fresh as it travels through the production line at Gebbers Farms in Washington state, USA.

“We don’t have the luxury to have downtime. We need things to work.”



Bob Grandy, Gebbers Farms

A three-story streamlined mass of pumps, valves, HDPE pipes and gleaming metal refrigerant condensing units form the “brains” of the facility. Together, these elements run a Geoexchange energy process that may be the first of its kind in the fruit-processing industry.

Inside the apple pre-size processing plant, forklifts deliver wooden bins of unsorted apples to a dunk tank, where the apples are cleaned and sanitized, and then the fruit is inspected for defects first electronically and then by human hands.

The water used throughout the facility is cooled by the Geoexchange system brine. The cooled water then flows into a cool-shower and flumes at minus 1.7 degrees Celsius. The water recirculates for a week through a closed system.

Chilled water preserves the fruits’ crisp, bright state, as if just plucked from the tree. In contrast, using room-temperature water hastens the ripening process, says Doug Lockhart.

Gebbers production
PHOTO: Gebbers Production

The Geoexchange cooling system at Gebbers may be the first of its kind in the fruit processing industry, according to Doug Lockhart of Lockhart Industries, the system’s supplier.

Wal-Mart sent representatives to view the new green initiative that produced better apples, economic savings and a sustainable processing approach.





High-quality results
“With little more than some innovative refrigeration equipment, pumping and controls, we were able to increase the quality,” he says. Less water is used as well, says Bob Grandy, and it is used more efficiently.

After being sorted, the apples are packed into bins and transferred into the cold-storage room, which the Geoexchange system also cools to minus 1.7 degrees Celsius.

“A real benefit of the system is that it cools rooms and water quickly,” he says. “And Grundfos pumps are instrumental in that process, by powering the heat exchange required for cooling the water.”

Eventually, the Geoexchange system could potentially be used in the underfloor heating or become part of the water treatment bio-system. Gebbers plans to integrate the Geoexchange in phases.

Grundfos CR pumps were extensively used due to their wide application to both available pressure and flow dynamics.

“They’re quite efficient and flexible with speed control,” Doug Lockhart says. “When CR pumps were coupled with the matched CUE frequency converter (Variable Frequency Drive), the Direct Digital Control system could control the flow tailored to the need.”


PHOTO: The Geoexchange system transfers excess heat into the ground in summer and pulls it from the ground in winter. Instead of creating chill, a heat pump moves existing chill.

Exceeding expectations

“Gebbers technicians have indicated that the Grundfos pumps work well, are efficient, and do the job,” says Bob Grandy. He emphasizes that the maintenance crew is happy with pump performance. “We don’t have the luxury to have downtime. We need things to work.”

Customers are happier too. Several of Gebbers’ top clients have sent representatives to view the new green initiative that produces higher-quality apples, economic savings and a sustainable processing approach.

“Although the new system was more expensive than a conventional system, we have found its accuracy, serviceability and overall performance to meet or exceed our expectations,” says Bob Grandy. “Once all of the features are fully implemented, we believe the system will provide further economical and environmentally sustainable results for our company.”

- Story and photos by Lora Shinn

Grundfos supplied
PHOTO: Grundfos UPS pumps withstand the Geoexchange and back-up boiler water temperatures.

Grundfos CR pumps and CUE frequency converters are installed for the main heat exchange in the large cooler, the condenser and pond.

• The flume chiller pumps are Grundfos LM body; with relatively short pumping requirements.

• Grundfos TP volute pumps are used in the flume condenser.

• Grundfos UPS pumps are employed in both the boiler and also the in-floor circulation to minimize equipment overhead; they could withstand the Geoexchange water temperatures and the back-up boiler temperatures.


Gebbers by numbers
PHOTO: Gebbers Farms manages nearly 8,000 acres of fruit trees in the Cascade Mountain Range in Washington, USA.

Created in 1909.
Located in Brewster, Washington.
Over 2,000 employees during peak season (July/October).
Operates mulitple work shifts/7days during peak season.
Manages more than 5,500 apple acres and 2,000 cherry acres.
Produces more than 225,000 bins of apples and more than 20,000 tons of cherries a year.

Cooling from the ground
PHOTO: A three-story mass of pumps, valves, HDPE pipes and metal refrigerant condensing units form the “brains” of Gebber’s facility.

About Geoexchange

The Geoexchange system in use at Gebbers relies on heat pumps and a network of durable plastic pipes that circulate into a holding pond. The pipes, filled with an antifreeze-water solution, act as a heat exchanger, extracting or releasing heat in the water, depending upon the season or building’s needs.

Much like a household refrigerator, the Geoexchange heat pump moves energy (the first law of thermodynamics), thus the heat pump create zones of high energy where you need heat and consequently, zones of low energy where you need cooling. Inside Gebbers, the interior water pipes distribute cooled water through the apple flumes.

According to the US Environmental Protection Agency, Geoexchange systems are the most energy efficient, environmentally clean, and cost effective space conditioning systems available.

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