Air Cooled Heat Exchangers

Choosing the Core and the Drive

The core type comes out of where the cooler sits. Bolted to structure in a deckhouse or a compartment, at moderate oil pressure, a tube and fin core does the job for less and is cleaned with a hose and mended with a comb and a tube plug. Bolted to the machine, on a crane pedestal, a winch base or a skid pack at 250 PSI, the brazed bar-and-plate block is the only one that stays tight. The comparison is set out on Bar and Plate.

The drive comes out of what is available at the mount. A switchboard feed and continuous running points to an AC motor and the A Series, with sizes to A275. Hydraulic hose and no electrical supply, which describes most crane and winch positions, points to the H Series taking pilot flow from the machine's own circuit, so the fan turns whenever the machine works. Where the only supply is the vessel's 12 or 24 volt system, the DCS Series covers small loads.

An air cooled selection lives or dies on the air-side temperature difference, which is much smaller than anything available with seawater. The design ambient has to be the air actually entering the core, which on a sunlit steel deck beside a hot exhaust can be well above the shade temperature anyone would quote from a weather table.

That makes siting part of the selection. Allow clear space on both faces so discharge air cannot recirculate into the inlet, keep the core away from engine exhaust and hot plating, and point the discharge somewhere nobody stands. A core with a good rating in a bad position performs like a much smaller core.