Refrigeration 2023

Last year saw some significant additions for Integrated Marine Systems (IMS), based in Mukilteo, Wash. The big change? New hires in the engineering department, with the father-and-son duo of Tom and Vince Giacalone coming on board.

“They’re working on RSW (refrigerated sea water) system design, sales engineering, quality control and updating BOMs (bills of material), manuals, and schematics,” Operations Director Kurt Ness told Fishermen’s News. “Vince is also spearheading a new product that will come to market in later (in) 2023; a revamped and modernized touchscreen RSW controller which will be fully customizable for specific applications and industries. The new controllers will also be able to replace old controllers and integrate with existing shipboard HMIs (human-machine interfaces) and PLCs (programmable logic controllers).”

IMS is also establishing itself in the service field, by hiring Tim McRae as lead refrigeration technician. He will spend the summer in Bristol Bay, Alaska servicing the gillnet and tender fleet. With this move, the company has said that it’s optimistic that the division will continue to grow and provide even more boots-on-the-ground service to various fleets in the future.

“We supply refrigeration systems to many different fisheries and fleets. Along with our core market of Alaska, we also do significant business along the West Coast, Gulf, the East Coast and Atlantic Canada,” Ness added. “Whether it’s salmon, crab, pollock or any other species, refrigeration is paramount.”

Another component IMS is re-introducing is educational refrigeration classes, which the company conducted throughout the 2000s in partnership with Washington SeaGrant. With the number of RSW systems IMS has on the market, the company has decided once again to provide one-day RSW courses with a focus on operation, maintenance and safety.

Course dates are yet to be determined, but they’ll be held at IMS’ Mukilteo facility throughout the year.

Highland Refrigeration

Seattle-based Highland Refrigeration’s equipment line includes, in addition to plate- and blast-freezers, RSW chillers and ice machines. Ice machines are more efficient on smaller fish boats in regions such as Hawaii and Alaska, as RSW tanks can cause surface water to slosh around and potentially damage fish. Even coastal Indian tribes are now implementing the practice, Highland President Lars Matthiesen said.

“The different tribes are putting in their own ice plants so that they can sell the fish to any buyer, not only to the buyer providing ice. Now no boats leave the dock without ice onboard,” he explained. “And according to one fish buyer, the product is worth a dollar more a pound, and it’s easily measurable in monies back in the pocket in final price of the product.”

One of the most popular ways for long liners to keep catch chilled is to use slurry ice.

“That means ice that is melting at about 30 degrees Fahrenheit, depending on the salinity,” Matthiesen said. “Sea water is about 28-and-a-half degrees. Typically, we have a little bit of fresh water in it, so we don’t partly freeze the fish—a process called slow freezing—which will also ruin the fish if it has to be frozen later on.”

“The idea,” he explained, “is that you keep it iced or slurry-iced and the slurry ice has the benefit that the fish is buoyant, which means you can have it in a tank without the risk of squeezing it on the bottom as you would do if you just dry-iced it.”

There are also other ways to chill sea water with titanium chillers that go down to 32 degrees, circulating the water around the fish.

“The key depends on the boats,” he continued. “If it’s on a boat that has a net with a lot of fish in at one time, it will take more time to get the temperature down. It also doesn’t matter about the size of the vessel. It’s the same laws of physics that count.”

Matthiesen notes that processing plants are now using recirculated chilled 33° Fahrenheit fresh water for water used in processing lines to keep the bacterial count down and not heat the fish by using regular city water, which might be 60-70° Fahrenheit.

Highland has adapted their refrigeration equipment to move with the times, so it is more compact, power-efficient and environmentally friendly. For example, ammonia or propane can be used as the primary refrigerant.

“As a secondary refrigerant, we can cool CO2 as a liquid and recirculate that to freezers and cargo holds, which means the system with compressors will be traditional,” he explained. “Ammonia water has the benefits of low viscosity and good heat transfer at atmospheric pressure, allowing for the use of PVC piping. The downside is that it still smells like ammonia.”

For power efficiency, the company’s screw compressors can run more than 50,000 hours before needing new bearings. However, screw compressors running at 10% still use 55% full-load power. “It’s terribly inefficient if it’s not used to the max. That’s why we design systems to utilize the best possible energy profile, utilizing the right size compressors.”

For larger systems, Highland may install a 100HP and 200HP compressor instead of a 300HP to gear the system towards the capacity required.

“Technology changes. Efficiency gets higher. Typically, a system that is more than 10 or 15 years old will save power by going to a more efficient system. The lifecycle of Highland units is impressive,” he said. “I have systems that I put in 40 some years ago that are still running today.”

The Arctic Fjord II at Thoma-Sea Shipyard in Louisiana. Photo courtesy of Teknotherm.


Another forward-thinking Seattle-based firm is also on the forefront of developing new, efficient, eco-friendly refrigeration systems. Teknotherm Inc. has successfully implemented an Ammonia-CO2 cascade freezing system for Arctic Fjord II, which will be delivered at Thoma-Sea shipyard in Louisiana, the first newly built vessel in the area to incorporate this system.

By adopting this system, the Arctic Fjord II sets a new standard for vessels operating in environmentally sensitive regions. The use of CO2 reduces freezing times under very low temperatures and reduces downtime.

With the phasing out of the R-22 refrigerant, due to its adverse environmental impact, Teknotherm also has proactively taken steps to facilitate R-22 to ammonia conversions.

Factory plate freezers on Arctic Fjord II, which has freezing systems designed by Seattle-based Teknotherm Inc. Photo courtesy of Teknotherm.

“By converting from R-22 to ammonia, fisheries not only comply with regulatory requirements, but also benefit from enhanced energy efficiency and reduced greenhouse gas emissions as well as reducing operational costs,” CEO Osman Colak said.

Pacific West Refrigeration

Pacific West Refrigeration, based in Saskatchewan, Canada, has been manufacturing RSW units for the commercial fishing industry since 1995. One of their bespoke designs is Titanium Turbo Chillers that have replaceable titanium coils and removable housings.

“Our PWR Titanium Turbo Chillers have their own technology,” company head of Sales and Support Shelly Boutilier explained. “We have a coil design and swirling technology which has it all—long-lasting titanium coils, amazing heat transfer ability, lightweight and an easily removable enclosure. The PWR Titanium Turbo Chillers are incorporated into our complete Refrigerated Seawater Systems.”

The company provides RSW units to vessels of all sizes, from a three-ton unit that would typically be installed on a small prawn or crab vessel, to a six-ton RSW unit for small vessels to 8.5-ton, 10-ton and up to 63-ton for large packers and tenders.

The company has also focused much of its RSW units on the Bristol Bay Fishing Fleet, particularly with their purpose-built hydraulic transom-cooled system.

“Why it works in Bristol Bay is because of the high-low tides,” Boutilier explained. “The hot refrigerant in the system is piped to the outside of the boat. It goes through the transom cooler, and then comes back into the RSW cool. So, we use the outside sea water to cool that refrigerant.”

(Top) A Pacific West Refrigeration RSW (refrigerated sea water) unit. Photo: PWR.
(Above) A Pacific West Refrigeration 10 ton electric drive. Photo: PWR.

This year, Pac West is focusing on new markets and ramping up production.

“I know within the next five years, there might be some changes as to what refrigerants you run for new systems,” Boutilier commented. “Then you have to change your components to match because you have to make sure you have the right oil and right refrigeration components that will run off of that type of refrigerant.”

Earlier this year, Alaska Wildlife Troopers stated that Bristol Bay drift gillnet fishboats can measure no more than 32 feet in length.

“They were cracking down on what people were putting on the backs of boats,” Boutilier told Fishermen’s News. “We hope they’re going to allow them this year, and then they’re going to rewrite the rules for the transom coolers in the next year or two to allow for them because it’s just a better system for the type of fishing in the Bay.”

“People can fish upriver without getting silt and sand in their condenser pump,” Boutilier said. “They’re addressing the rules to account for new technology, which is great to see.”

Weighing In

Wally McDonald, now semi-retired, but formerly with Alaska-based Fleet Refrigeration, weighs in on changes with refrigerants to address environmental concerns.  

Current trends he sees as continuing is the changeover of refrigerants (the halocarbons known generally as Freon) to address environmental concerns.

A few decades ago, the Montreal Protocol began the phase-out of refrigerants containing chlorine in their formulation because of evidence of atmospheric ozone. The industry was able to respond by developing refrigerant blends that reduced the amount of chlorine required.

Subsequently, new formulations known as HFC (hydrofluorocarbon) refrigerants were developed and marketed and have come into wide use. However, subsequent research has shown these formulations, while they don’t deplete atmospheric ozone, they do contribute to global warming. In the last few years, formulations have been assigned a global-warming potential (GWP) value.

More formulations with a lower GWP have been, and he said he assumes are continuing, to be developed.

The cost of all these formulations has increased refrigerant prices dramatically and is subject to a great deal of fluctuation. One significant result has been to develop efficient system designs that utilize the smallest practical charge of refrigerant. Control-system designs also have evolved and become reliable so that components such as manually set expansion valves that feed refrigerant into the chiller component can be replaced with electronic step-motor valves that automatically adjust to feed the refrigerant very precisely based on the system heat load.

Variable frequency driven motors on pumps and compressors, which can alter speed based on load, are also being used increasingly to achieve more efficient operation. 

Kathy A. Smith writes for global maritime trade journals and provides marketing copy to maritime businesses worldwide. She can be reached at