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EngineeringRefrigeration Capacity Calculator
Free online refrigeration capacity calculator for cold storage, freezers, and cooling systems. Calculate required cooling capacity in BTU/hr, tons, and kW based on heat load and temperature.
The Refrigeration Capacity Calculator helps you determine the required cooling capacity for refrigeration systems, cold storage, and freezers based on heat loads and temperature requirements.
What is Refrigeration Capacity?
Refrigeration capacity is the amount of heat a refrigeration system can remove from a space or product per unit time. It's measured in BTU/hr, tons of refrigeration, or kilowatts. One ton of refrigeration equals 12,000 BTU/hr or 3.517 kW - the amount of heat required to melt one ton of ice in 24 hours. Proper capacity calculation ensures the refrigeration system can maintain desired temperatures while handling all heat loads including transmission through walls, product cooling, infiltration, people, lighting, and equipment.
Heat Load Calculation Formulas
- Transmission Load: Q = U × A × ΔT (where U = thermal conductivity, A = area, ΔT = temperature difference)
- Product Load: Q = m × cp × ΔT (where m = mass, cp = specific heat, ΔT = temperature change)
- Infiltration Load: Q = V × ρ × cp × ΔT × air changes
- Total Capacity: Sum of all heat loads × safety factor (typically 1.1-1.25)
Heat Load Components
- Transmission: Heat gain through walls, floor, and ceiling
- Product load: Heat removal from products being cooled or frozen
- Infiltration: Warm air entering through door openings
- People: Heat generated by occupants (250-400 BTU/hr per person)
- Lighting: Heat from lights (3.41 BTU/hr per watt)
- Equipment: Heat from motors, forklifts, and other equipment
- Defrost: Heat required for periodic defrosting (in freezers)
Design Recommendations
- Add 10-25% safety factor to calculated capacity
- Use thicker insulation for lower temperatures (4-6 inches for freezers)
- Minimize door openings with strip curtains or air locks
- Consider pull-down time requirements for initial cooling
- Account for peak loads (maximum product input per day)
- Use evaporator coil temperature 10-15°F below room temperature
- Plan for defrost cycles in freezer applications
- Consider ambient temperature variations throughout the year
Common Applications
- Cold storage warehouses and distribution centers
- Walk-in coolers and freezers for restaurants
- Supermarket refrigeration systems
- Food processing and packaging facilities
- Pharmaceutical cold storage
- Floral storage rooms
- Meat aging rooms
- Ice rinks and skating facilities
- Industrial process cooling
