Preventing Clogged Marine Air-Conditioning Intakes

ElectroSea’s Clearline prevents barnacles and scale from clogging intake strainers and damaging systems.

July 7, 2020

Genius is one percent inspiration and ninety-nine percent perspiration.

Thomas Edison

Thomas Edison wasn’t wrong, and Dr. Lou Cosentino was certainly in agreement on the perspiration part as his 72-foot Viking’s AC units experienced high pressure alarms due to marine growth in the seawater cooling lines. His determination was crystallized after cancelling too many fishing trips and shelling out the umpteenth C-note to have his Viking’s AC cooling water intakes descaled to return his AC to operation.

Clearline system and components
The Clearline system is available for plumbing sized at 3/8-inch and flow rates of 7 GPM up to plumbing sized at 2-inches and 75 GPM flow. Systems can be linked to provide greater capacity. Courtesy ElectroSea

Caption: The Clearline system is available for plumbing sized at 3/8-inch and flow rates of 7 GPM up to plumbing sized at 2-inches and 75 GPM flow. Systems can be linked to provide greater capacity.

And then Lou’s inventing mind went into warm up mode. Already the originator of more than 100 U.S. Patents on medical devices and over 350 foreign patents, Cosentino started developing prototypes of an electrochlorinator specifically designed to keep scale and barnacles from damaging marine cooling systems at essentially no operating cost with minimal maintenance.


The challenges were tough but not unsurmountable with some original thinking. First, to survive in a harsh sea water environment the system had to be electrically isolated so it wouldn’t allow electrolysis. The electrodes needed special rare earth coatings to catalyze the conversion of sodium chloride in the seawater to chlorine. The electrode design needed to be optimized for long life and efficient operation. ElectroSea calls this proprietary electrode component ClearCell.

A significant problem which had to be overcome was the deposition of carbonates on the electrodes. This was solved electrically with a tiny computer control system. The computer matches chlorine levels to seawater flow. By the time the product was ready for patenting, these challenges had all been met and proven in personal testing of prototypes over several years. The product was logically called ClearLine, referring its function in keeping cooling lines clean. A second feature that was added was to direct chlorinated seawater back to the input side of the intake strainer to also keep it free of growth.

Some Captains praise this feature because it reduces their need to check and clean the strainer from days to several weeks. “Like clockwork , I would clean my AC strainer every Tuesday for years until we installed the ClearLine system. Based in Jupiter, Florida the water around our dock can get really warm, especially in summer, and the barnacles, sludge and sea critters would thrive in our AC system. After installing ClearLine, I only check on my AC strainer about every five weeks. When I do check it, I hardly clean anything, no barnacles or gunk. I’ve had the system installed for six months now, and can honestly say this will change how the industry thinks about descaling saltwater systems. I haven’t had to call for air-conditioning service since we installed it”, Captain Harry Schaffer, 66 Viking Yachts, “Sea Wolf”. In my opinion ,this is one of the best improvements to boating in recent years”.

Comparison of with and without Clearline
Barnacles, growth and scale can really clog intakes, as this side-by-side image shows. Courtesy ElectroSea

Viking Yachts, the manufacturer of sport fishing boats was one of the first OEM customers and offers the ClearLine system as an option in all their boats. Viking brings in their raw water for cooling systems via manifolds—usually stainless steel housings with a single through-hull fitting feed. On a Viking, various water supply lines are run from the manifold, including the livewells. ElectroSea added a sensor in the controller that shuts down chlorination when live well pumps are energized.

So, what about the chlorine going back into the ocean?

“Ensuring that ClearLine is environmentally-safe was an essential requirement in product development,” said Allison Reis, marketing and communications manager for ElectroSea. “Chlorine has been shown over many years to be a safe and effective solution for preventing marine growth in desalination plants and offshore oil rigs, as well as industrial cooling towers. In fact your drinking water contains chlorine to keep it safe and free of pathogens. Chlorine has a very short life in sea water and by the time the water exits the boat, the chlorinated sea water has decomposed back into salt (sodium chloride) and water.”

Clearline system in place
Clearline system shown installed. Courtesy ElectroSea

ClearLine models range in capacity from 7 GPM to 55 GPM. So far ElectroSea has equipped boats to 112 feet and can increase capacity by connecting multiple systems in parallel. Soon they say, a 75 gpm unit will be available.

ElectroSea markets through dealer networks who are also installers. Pricing is packaged with installation and can range in $3,995 to $8,540 for a single system, plus installation. Some vessels may require two systems, depending on their configuration. In addition to Viking Yachts, ClearLine has been installed on numerous luxury boats and continues to grow in popularity.

Descaling your lines can cost $2000 per episode and in some waters that needs to be done three times per year. Yacht owners in Costa Rica report having to do it every other month.


Brian Peterson, owner and managing partner of Harbor Town Marine in Dania Beach, Florida says its cost is a bargain for a variety of reasons. “One owner we service had to replace 4 AC’s over the course of his ten year ownership due to system overheating from scale,” he said. “And, when the waterflow is just restricted by scale—something that can begin in two weeks or less– cooling is not efficient and the boat can get sweaty.”

Read Next: Installing a Seacock

Considering the cost of descaling in the first year, Tom Carroll, president and CEO of Princess Yachts America says, “The ClearLine system effectively costs nothing,” and installs them on all boats he inventories.

ElectroSea says with their system, you’ll never have to descale again. They’ve been installed on hundreds of vessels from 34′ and up, and customers rave about its performance. “The Electrosea system has been incredible since we installed it. Approaching three months with the ClearLine system and absolutely zero growth. Every boat should have one”, said Captain James Brown, 90′ Jarrett Bay, ‘Jaruco’.


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