Ice Cold and Dynamic

The commercial fishing trawler Arctic Fjord at a pier preparing for her first trip. Photo courtesy of Teknotherm.

Cold storage systems have come a long way since the copper coils of yore that shivering deckhands needed to constantly scrub to keep frost-free. While the layperson may shrug at the sight of a hold of properly chilled fish, the commercial fishing professional sees engineering glory and big-money dollar signs.

From the 50-foot salmon seiner to the 300-foot factory trawler, what are fishing vessels if not giant floating freezers?

If only our ancestors of hundreds of years ago who kept cod fresh in barrels of salt could see us now. Fortunately, cold-storage technology is a dynamic sector that seems to keep getting better.

State of the Refrigeration Business

There are many players in the commercial fishing cold-storage game, including Washington state-based companies like Highland Refrigeration, which was founded in 1999. Like many cold storage outlets, Highland services clients across the food industry, with an emphasis on customized solutions.

It notably provided and installed a new refrigeration system with two additional plate freezers to the O’Hara Corp.-owned 229-foot freezer trawler f/v Alaska Spirit.

The refrigeration room aboard the f/v Arctic Fjord. Photo courtesy of Teknotherm.

Another Washington cold storage company is Mukilteo-based Integrated Marine Systems, which services fisheries in Alaska, the West Coast, the Gulf of Mexico and the Northeast. The company’s founders reportedly were Alaska fishermen, and IMS’ first products were developed to benefit small salmon boats. The company has since expanded its scope to service a wide variety of commercial fishing vessels.

Internationally, Teknotherm Refrigeration began in 1929 as a small group of engineers in Norway united by a shared vision of revolutionizing refrigeration technology.

“Initially serving the maritime industry, they quickly gained renown for their innovative systems built to withstand the rigors of the sea,” Teknotherm CEO/President Osman Colak said. “Over the decades, Teknotherm expanded its reach into industrial refrigeration and HVAC systems, earning a reputation for reliability and excellence.”

Teknotherm entered the U.S. market in 1987 with a focus on the needs of commercial fishing vessels: design and engineering, project management, preventative maintenance and troubleshooting, spare parts and remote-system monitoring as part of after-sales support.

“Teknotherm Refrigeration offers several best-selling and notable products tailored for the commercial fishing sector, designed to meet the unique refrigeration needs of vessels operating in harsh marine environments,” Colak said.

Among their bestselling and notable products include RSW (Refrigerated Sea Water) Systems. These systems are designed to rapidly chill harvested fish by circulating refrigerated sea water through onboard tanks, ensuring optimal freshness and quality during transportation.

According to Colak, the systems are so well designed that there are Teknotherm RSW systems that were installed on commercial fishing vessels in the 1990s still working today.

Blast freezers and plate freezers are both key Teknotherm products. Blast freezers are essential for preserving the quality of fish caught at sea. These high-capacity freezers rapidly lower the temperature of freshly caught fish to ensure minimal deterioration in texture and flavor, maintaining market value and quality.

Plate freezers offer efficient freezing solutions for onboard fish storage. These systems utilize flat plates to freeze fish quickly and uniformly, maximizing storage capacity while preserving quality.

Teknotherm also offers a range of ice machines tailored to the needs of commercial fishing operations. These machines produce high-quality ice for chilling fish and storing catch, ensuring freshness and preserving quality during extended fishing trips.

The f/v Northern Eagle, owned by American Seafoods, recently underwent an ammonia conversion upgrade. Photo courtesy of Teknotherm.

Modern Frontiers: Remote Monitoring, Natural Refrigerants and More

These days, companies like Teknotherm provide advanced control and monitoring systems designed in-house for the commercial-fishing industry. These systems offer real-time monitoring of temperature, pressure and other critical parameters, ensuring optimal performance and reliability of refrigeration equipment onboard vessels.

At the time of this writing, Teknotherm is in the process of updating automation systems with remote monitoring and new safety features on fishing boats such as American Seafood’s f/v American Dynasty.

Like many technology sectors these days, “smart” controlling is being utilized. Smart refrigeration control systems are equipped with sensors, IoT (Internet of Things) connectivity, remote monitoring and other optimizing features.

These smart controls can detect inefficiencies, identify potential issues before they occur, and adjust system parameters for maximum efficiency and performance.

Natural refrigerants, as opposed to traditional standards like R-22 freon, also are becoming more mainstream.

“There’s a growing trend towards using natural refrigerants such as ammonia, CO2 (carbon dioxide) and hydrocarbons like propane and isobutane,” Colak said. “These refrigerants have low global-warming potential (GWP) and ozone-depletion potential (ODP), making them more environmentally friendly alternatives to traditional synthetic refrigerants like HFCs (hydrofluorocarbons).”

“Ammonia and CO2 are thought to be the major refrigerants for the foreseeable future of refrigeration related to frozen-at-sea and on-land fish processing products,” he added.

According to Colak, Variable Refrigerant Flow (VRF) systems also are gaining popularity due to their energy efficiency and flexibility. These systems use refrigerant-flow control to precisely match the cooling or heating capacity to the specific requirements of different zones or compartments on a boat, resulting in energy savings and improved product quality.

Thermal energy storage systems are also a newer innovation. These systems utilize phase-change materials or ice to store excess refrigeration capacity during off-peak hours. This stored thermal energy then can be used during peak demand periods, reducing energy consumption and operating costs.

This technology is used mostly on land-based solutions where power availability and consumption amount matter most.

A refrigerated seawater compressor on the f/v Northern Eagle. Photo courtesy of Teknotherm.

“These are just a few examples of the innovative technologies driving advancements in refrigeration and cold storage, with a focus on sustainability, efficiency and improved performance to meet the evolving needs of various industries,” Colak said. 

Notable Installs

American-built, state-of-the-art commercial fishing trawler f/v Arctic Fjord made headlines in 2023 when it began sea trials. Such a vessel has massive cold storage demands and uses a Teknotherm ammonia/CO2 system. The choice correlates with the broader natural refrigerants trend in the industry.

“Teknotherm completed the delivery of a complete Ammonia/CO2 cascade refrigeration system supported by RFW (refrigerated seawater) chillers for the new fishing vessel Arctic Fjord proudly operated by Arctic Storm Management LLC,” Colak said.

The vessel, which was built at the Thoma-Sea shipyard in Louisiana, is the most recent addition to the Alaskan fisheries fleet. The system’s design was initiated by Bowman Refrigeration and cooling technology manufacturer Mayekawa, but was completed by Teknotherm following its acquisition of Bowman Refrigeration in 2021.

“We had the chance to combine the expertise of three trusted companies along with the support of our valuable partners during the completion of the project,” Colak said.

Another example of going “natural” is the f/v Northern Hawk, operated by Coastal Villages. An ammonia-driven freezing system is planned for installation in 2025.

“The new system will not only eliminate the use of high GWP (global-warming potential) and cost R-22 (refrigerant), but also increase efficiency by the use of modernized control technologies,” Colak said.

The f/v Northern Eagle, owned by American Seafoods, also has undergone an ammonia conversion upgrade by Teknotherm.

“Teknotherm has completed the ammonia conversion of all American Seafoods fleet refrigeration systems in the past years and f/v Northern Eagle was the most recent one,” Colak said. “With this upgrade, which was done in 2023, the boat increased freezing capacity and improved the use of space on the vessel.”   

Norris Comer is a Seattle-based writer and author. His debut memoir, Salmon in the Seine: Alaskan Memories of Life, Death, & Everything In-Between is now available wherever books are sold. You can find him on Substack, Instagram and at He can be reached via email at