Views: 0 Author: Site Editor Publish Time: 2026-05-21 Origin: Site
Also called Sea Chest Box Cooler, a tubular heat exchanger installed inside the vessel’s sea chest. Tube bundle material mostly CuNi 90/10, submerged directly in static/flowing seawater. Internal circuit: fresh water / lube oil / hydraulic oil for engine cooling.
Mounted externally on the keel / hull bottom, exposed fully to ambient seawater flow while underway. Also CuNi 90/10 tube bundle, uses natural seawater flow for cooling, no sea chest needed.
Item | Box Cooler | Keel Cooler |
|---|---|---|
Installation Position | Inside sea chest (inboard) | External hull / keel bottom (outboard) |
Cooling Principle | Static + natural convection in sea chest | Forced flow by vessel moving through water |
Material | CuNi 90/10 standard | CuNi 90/10 standard |
Space Occupation | Takes sea chest space; compact in engine room | No inside space needed; occupies hull external area |
Cooling Efficiency | Medium; drops with sea chest debris | Higher; better flow & heat exchange underway |
Maintenance Access | Easy onboard; pull out bundle for cleaning | Harder; requires dry dock / slipway |
Risk of Damage | Low; protected inside hull | High; collision, grounding, floating debris impact |
Biofouling & Sediment | Easy silt/shell buildup in sea chest | Less fouling due to constant water flow |
Vibration Resistance | Good for tugboats, workboats | Moderate; exposed to wave impact |
Cost | Lower purchase & installation cost | Higher fabrication + hull fitting cost |
Dependence on Speed | Low cooling drop at low speed/idle | Poor cooling when vessel stationary / low speed |
✅ Pros
Fully protected inside hull, no grounding/collision risk
Works well at idle, low speed, anchored
Easy inspection, cleaning, replacement onboard
Lower investment cost
Perfect for vessels with frequent stop-start operation
❌ Cons
Prone to silt, mud, marine growth inside sea chest
Cooling efficiency limited by static seawater
Occupies sea chest volume
✅ Pros
Higher cooling efficiency when cruising
Less fouling due to continuous water flushing
Saves internal sea chest / engine room space
Ideal for vessels running long hours at constant speed
❌ Cons
Vulnerable to grounding, floating trash, collision
Cannot maintain good cooling when stationary
Maintenance needs dry dock; cannot repair onboard easily
Higher manufacturing and hull installation cost
Tugboats, Workboats, Harbour Boats
Fishing vessels with frequent anchoring
Vessels operating in shallow, muddy, silty water
Boats with frequent idle / low-speed operation
Vessels wanting easy onboard maintenance without dry dock
Yachts, Patrol Boats, Fast Crew Boats
Coastal / offshore vessels running long steady cruising hours
Deep-water operation, rare grounding risk
Limited sea chest space inside the hull
Priority on high cooling performance at sailing speed
