Kelvion – Box Cooler

Kelvion – Box Cooler


A Box Cooler is a vessel water cooling system. It comprises a U-tube bundle that is fitted in the sea chest on the side of a vessel, saving space in the engine room. The sea chest is equipped with inlet and outlet grids. Cooling sea water enters through the inlet grid and flows along the U-tube bundle to the outlet grid, thus cooling the water inside the tubes. The cooling effect is achieved by the forced circulation of sea water when the vessel is moving or by natural convection when it is stationary.

Box coolers can be used for a wide variety of temperature-reducing duties on a vessel, from cooling the main engines, auxiliary engines and bow thrusters to air conditioning and hydraulic systems. Kelvion Box Coolers are ideal for small and medium sized vessels, including for example: tugboats, barges, fishing boats, carriers, dredgers, supply vessels, ferries, ice breakers, cargo freighters, tankers and reefers.

Versatile technology to suit your needs

The cooling power of the Kelvion Box Cooler is matched by its versatility. Its simple design can be configured in different versions and shapes to suit the available space and cooling requirements. To cover a wide range of cooling duties and constructive boundary conditions, Kelvion Box Coolers are available in many variations in round and rectangular design. The round shape is mainly for purposes with smaller cooling capacities. This type covers cooling surfaces between 2 – 21 m². The maximum possible diameter of the bundles is about 400 mm.

The rectangular form is used for larger cooling capacities and covers cooling surfaces between 9 to 120 m². The width of the box cooler bundle goes up to about 400 mm, while the maximum length is about 2000 mm. As the space available for the box cooler is often limited in the sea chest, the bundle must follow the contours of the hull as closely as possible to generate the largest possible cooling surface. This is achieved by executing the box cooler with a stepped bundle in several sections, each with a different depth. Independent of the design Kelvion Box Coolers are available with bundle depths between 400 and 1800 mm. Even bigger types are available on request.


For sailing areas where biological fouling could be an issue, we can provide special anti-fouling systems. Kelvion focuses mainly on the so called ICAF-Systems. The Impressed Current Anti-Fouling system (ICAF) is a very effective way of preventing biological fouling. Anodes of pure copper are mounted under the box cooler in the sea chest. A constant current is applied between the anodes and the hull (mass), which causes copper to dissolve in the seawater. These Cu+ ions create a continuous toxic environment preventing the settling of deposits.

We offer two different methods for installing the ICAF system:

– Separate ICAF-System

– Integrated ICAF-System

– Beside the ICAF system also Ultrasonoic Anti-Fouling systems (USAF) are available, but here a case by case evaluation must be done.


Our PowerBox is a passive cooling system for run-of-river hydro power plants – another application using the advantages of the box cooler. It is installed in the plant’s main water flow channel, totally submerged in the river water, which means that a heat exchanger shell and pumps are obsolete. The water simply surrounds the U-tube bundle and a forced flow on the outside is automatic, due to the water velocity in the channel.