Marine Refrigeration Sizing

Calculate refrigerator/freezer compressor requirements for boats

Refrigerator Box

x x
Length x Width x Height

Operating Conditions

Cooling Requirements

Cooling Load --
Compressor Size --
Box Volume --
Surface Area --
R-Value (total) --
Heat Leak --

Power Requirements

Run Time (daily est.) --
Power Draw (running) --
Daily Energy Use --
Solar to Offset (4h sun) --

Insulation R-Values

Material R-Value/inch 3" Total
Vacuum PanelR-25R-75
Closed-Cell FoamR-6.5R-19.5
Polyurethane FoamR-6R-18
Styrofoam/EPSR-4R-12
FiberglassR-3R-9

Marine Refrigeration Guidelines

Insulation: Minimum 3" of polyurethane foam for refrigeration, 4"+ for freezers. Top-opening boxes are significantly more efficient than front-opening.

Compressor Sizing: Select compressor capacity 20-30% above calculated heat load to ensure adequate cooling in hot conditions.

Holding Plates: For engine-driven systems, holding plates should have capacity for 8-12 hours of cooling between engine runs.

Efficiency Tips: Pre-cool food before loading, minimize door openings, add cold packs when possible, and ensure proper ventilation around condenser.