What Fernstrum does

R.W. Fernstrum & Company, operating as Fernstrum, is a fourth-generation, family-owned manufacturer of marine heat exchangers and closed-circuit cooling systems headquartered in Menominee, Michigan. Founded in 1945 and in continuous operation since 1949, the company designs and produces three core product lines: the GRIDCOOLER keel cooler (its flagship, patented since 1945 with a proprietary rectangular tube architecture and an exclusive enhanced interior tube surface delivering up to 30% higher heat transfer), the WEKA Boxcooler (copper-nickel closed-circuit cooling manufactured under exclusive Americas license from Dutch partner WEKA Marine B.V. since 1997), and Omega Laser Plates (laser-welded plate heat exchangers offered via partnership with Omega Thermo Products). Each unit is custom-engineered to vessel, engine, and operating-condition specifications.

The business model is direct-engineered B2B with quote-based pricing. Sales are executed through a combination of an in-house sales and engineering team and a network of 24 authorized representatives across six continents, targeting shipyards, vessel operators, and government marine fleets. Customer concentration spans dredging (Weeks Marine), towing (McAllister Towing, Foss Maritime), ferry operations (Washington State Ferries), offshore support (Bordelon Marine, Harvey Gulf), and emerging industrial/stationary applications including offshore wind, hydroelectric, and underwater data center cooling. The firm is ISO 9001:2015 certified (through September 2026), the only marine heat exchanger firm accepted as a Green Award Incentive Provider, and Green Marine certified.

Revenue is not publicly disclosed; with approximately 41 employees and no external funding or M&A activity on record, Fernstrum operates as a privately held, conservatively financed niche industrial manufacturer whose principal growth levers are product-line extension via partnerships and incremental vertical penetration into non-marine stationary heat-exchange applications.

Name

Fernstrum

Legal name

R.W. Fernstrum & Company

Website

https://fernstrum.com

Company type

Private

Founded year

1945

Operating status

Operating

Headcount range

11–50 employees

Short description

R.W. Fernstrum & Company is a fourth-generation, family-owned Menominee, Michigan manufacturer of custom marine heat exchangers — including GRIDCOOLER keel coolers, WEKA Boxcoolers, and Omega Laser Plates — serving commercial, government, and offshore vessel operators across six continents.

Ownership category

akta.pro rank

Product category

Marine Heat Exchangers

NAICS

Power Boiler and Heat Exchanger Manufacturing (33241)

SIC

Air-Cond & Warm Air Heatg Equip & Comm & Indl Refrig Equip (3585)

akta.pro primary industry

Propulsion Cooling, Lubrication & Auxiliaries (Pumps, heat exchangers, filters) (IMAJAHAL)

akta.pro secondary industry

Heat Exchangers & Thermal Transfer Equipment (IMAHAKAC)

Keywords

• Marine heat exchangers
• Keel cooling systems
• Marine cooling technology
• Closed-circuit cooling
• Shipboard heat exchangers

Headquarters

HQ city

Menominee

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Personnel, Technology or R&D, Supply Chain, Operations, Marketing or Sales

Revenue model

1. Custom GRIDCOOLER Keel Coolers: Custom-designed keel coolers engineered to meet requirements of engine, vessel, and operating conditions. Primary product line since 1949.
2. WEKA Boxcoolers: Copper-nickel boxcoolers manufactured under partnership with WEKA Marine B.V. for North and South American markets.
3. Omega Laser Plates: Laser plate heat exchangers for closed-circuit heating and cooling applications through partnership with Omega Thermo Products.

Pricing tiers

Go-to-market motion2 records

Distribution channels2 records

Marketing channels5 records

Core offering

R.W. Fernstrum & Company engineers and manufactures custom marine heat exchangers and cooling systems, including the GRIDCOOLER Keel Cooler, WEKA Boxcooler, and Omega Laser Plate products. These solutions cool propulsion engines, generator sets, reduction gears, and auxiliary systems onboard commercial, government, and recreational vessels, providing closed-circuit cooling that eliminates seawater intrusion, raw water pumps, and environmental discharge.

Product overview

R.W. Fernstrum & Company is a manufacturer of marine heat exchangers and cooling systems. The product portfolio centers on three main offerings: the GRIDCOOLER Keel Cooler (the flagship product and world's #1 keel cooler), the WEKA Boxcooler (a compact closed-circuit system offered through a partnership with WEKA Marine B.V.), and the Omega Laser Plate (laser-welded heat exchanger plates offered through a partnership with Omega Thermo Products). These products work together to provide complete cooling and heating solutions for marine propulsion engines, generator sets, reduction gears, and auxiliary systems on vessels of all sizes worldwide. Each solution is custom-engineered to meet specific engine, vessel, and operating condition requirements.

Differentiator

Problem solved

Functional benefit

Brands

• GRIDCOOLER: The world's leading keel cooler product line, featuring rectangular tube heat exchangers for marine propulsion engines, generator sets, reduction gears, and auxiliary systems.
• WEKA Boxcooler
• Omega Laser Plate

Products and services

• GRIDCOOLER Keel Cooler Custom-designed rectangular tube keel cooler serving as the world's #1 keel cooler for marine propulsion engines, generator sets, reduction gears, and auxiliary systems onboard vessels. Features a one-piece header design, fatigue-resistant high-silver content joints, ultrasonically inspected brazed joints, and an exclusive enhanced interior tube surface that increases heat transfer by up to 30 percent.
• WEKA Boxcooler Compact closed-circuit cooling system mounted within a sea chest inside the vessel's hull, manufactured from 90/10 copper-nickel with natural anti-fouling capabilities and WEKA Protector Type T systems for corrosion protection. Cools engines up to 10,000 kW and offers protection from submerged obstacles in icy, sandy, or debris-laden waters.
• Omega Laser Plate Laser-welded heat exchanger plates available in immersion plate and pillow plate configurations for closed-circuit heating and cooling applications. CNC-programmed laser welding enables custom shapes, recesses, fastening points, and connections, with cost-effective low welding costs and thinner materials.

Quantifiable outcome

• Enhanced tube increases heat transfer capability by up to 30 percent
• +2 more outcomes

Named customers6 records

Segments3 records

Ideal customer profiles2 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature6 records

Partnerships

Four partnerships are on record, tiered core and minor.

• WEKA Marine B.V.coreStrategic or Co-development Partner · 1 January 1997Partnership with Dutch company WEKA Marine B.V. to manufacture and sell copper-nickel boxcoolers for North and South American markets. WEKA Boxcoolers are compact closed circuit cooling systems mounted in sea chests within the vessel's hull. Fernstrum has exclusive manufacturing and sales rights for the Americas.
• Omega Thermo ProductscoreStrategic or Co-development PartnerPartnership to bring laser plate technology to marine and industrial markets. Omega Thermo Products is the inventor of the laser welding machine for Laser Plates. Fernstrum offers Omega Laser Plates for closed-circuit heating and cooling applications.
• Green Award NetworkminorOthersGreen Award Network is based in Rotterdam, Netherlands and vets the global marine industry for companies meeting stringent environmental requirements. Fernstrum is the only marine heat exchanger company and one of only 185 incentive providers worldwide.
• Green MarineminorOthersGreen Marine is a voluntary environmental certification program for the North American marine industry. Fernstrum is committed to improving environmental performance beyond required regulations.

Scale indicators7 records

Recent moves6 records

Expansion highlights6 records

Broad incumbents

• Wärtsilä: Major marine engine OEM and systems integrator with its own auxiliary cooling and heat exchange offerings. Comparable to Fernstrum as a marine cooling supplier but operating as a much larger engine-and-systems incumbent that often specifies or supplies its own cooling systems.
• Alfa Laval: Global marine and industrial heat transfer giant offering plate heat exchangers, freshwater coolers, and complete engine cooling packages. Comparable to Fernstrum in marine cooling end-use, but operates at much larger scale, with broader product breadth and global engineering resources that compete with Fernstrum's specialty focus.
• SPX Cooling Technologies: SPX's heat transfer division manufactures a wide range of heat exchangers and cooling equipment for industrial, HVAC, and process applications. Comparable as a heat exchange manufacturer serving industrial and process customers, though its marine exposure is more limited than Fernstrum's.
• Kelvion: Manufacturer of heat exchangers for marine, power, and industrial applications, including plate, shell-and-tube, and freshwater cooling systems. Closest comparable to Fernstrum at the heat-exchanger manufacturing level, but with a much broader product portfolio and global service network.

Direct peers

• API Heat Transfer: Specialist heat exchanger manufacturer serving marine, oil & gas, and industrial markets with shell-and-tube, plate, and air-cooled products. Comparable to Fernstrum as a specialist heat exchanger supplier competing in marine and industrial cooling.
• Tranter: Manufacturer of plate heat exchangers used in marine, refrigeration, and process industries. Comparable to Fernstrum as a specialist heat exchanger supplier in marine and industrial cooling, though its plate-frame focus differs from Fernstrum's keel and box cooler core.
• Bowman (EJ Bowman): UK-based manufacturer of heat exchangers including marine engine cooling solutions (keel coolers, box coolers, freshwater coolers). Direct competitor to Fernstrum in marine engine cooling, particularly in the European commercial and workboat segments.

Others

• WEKA Marine B.V. Dutch designer of WEKA Boxcoolers and Fernstrum's exclusive Americas partner. Comparable to Fernstrum in boxcooler product technology, but as a partner rather than competitor in the Americas; in Europe and other regions WEKA sells through its own channels, making it a partial regional competitor.
• Omega Thermo Products: Inventor of laser-welded plate heat exchangers and Fernstrum's laser plate technology partner. Comparable as a heat exchanger technology provider, but as a supplier/partner rather than direct competitor in the marine cooling applications where Fernstrum is the channel.

Emerging players

• Haskris Company: Smaller US manufacturer of liquid-to-air and liquid-to-liquid heat exchangers for industrial, medical, and process cooling. Comparable to Fernstrum at the heat exchanger manufacturing level, but with a focus on air-cooled and process cooling rather than marine keel cooling.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

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Compliance1 record

Revenue estimate

Valuation estimate

Number of profiles

Profiles13 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Fernstrum