Work needs to get done. Engines need to run. Water needs to churn. All day, every day. Fernstrum coolers stand alone for reliability, performance, and durability. And Fernstrum people stand above for expertise, service, and responsiveness.
2025 Performance Metrics
99.8%
96.8%
Marine Cooling Solutions
We build marine heat exchangers that are designed to be the best solution for tugboats, ferries, work boats, fishing boats, and other vessels. In doing so, we consider engine performance, operating environment, and the nature of work being done in order to deliver coolers you can depend on month after month, year after year. This means working harder and going further, using higher grade metals, and employing superior manufacturing processes.
FERNSTRUM® GRIDCOOLER® Keel Cooler
Available in 90/10 Copper-Nickel and 5000 Series Aluminum, these coolers are the clear leader for reliability and longevity.
The GRIDCOOLER Keel Cooler is mounted externally on the hull below the waterline. The engine coolant is circulated through the GRIDCOOLER Keel Cooler, which transfers heat from the coolant before it returns to the engine. The keel cooler is in constant contact with seawater to efficiently transfer heat.
“My boat is my living and every day counts. Bruce worked with me to figure out the cooler I needed, get the cooler built and ship it out almost immediately.”
Testimonial
“RW Fernstrum has always been amazing to work with. I am very appreciative that there is rapid response from the sales team members, offering a standardized list of information that includes installation drawings, data for the calculation and honest pricing. This saves us all time and helps us stay competitive in the local Marine Market.”
Testimonial
“I was in a bind and the team at Fernstrum got me going in a matter of days. The whole process from initial contact to shipping and actually receiving the cooler could not have gone any smoother. Thank You!!!”
Testimonial
“I have Fernstrum coolers that have been on my boat since 1981.”
Testimonial
"I want to thank your team for the excellent assistance in taking the order on short notice and shipping everything the same day as the order was made.”
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