What does a blast freezer cost for your tonnage?

Calculation method

1. batch heat = product mass × product enthalpy removal × target-temperature factor
2. freezing duty = batch heat ÷ cycle seconds
3. plant duty = freezing duty × 1.20 fan, defrost and design allowance
4. annual electrical energy = plant duty ÷ COP × cycle hours × operating days
5. CAPEX band = plant duty × selected system USD/kW factor × low/high range

Batch input switches between tonnes and pounds; refrigeration output is shown in kW, TR and BTU/h. Calculations remain in canonical SI units.

Worked example

Freeze a 20 t (44,092 lb) fish batch to a −18 °C core in an air-blast tunnel.

Inputs

• • 20 t batch
• • 290 kJ/kg product enthalpy removal
• • 8 h cycle
• • 20% plant allowance

Calculation

• • Heat removed = 20,000 × 290 = 5,800,000 kJ
• • Freezing duty = 5,800,000 ÷ (8 × 3,600) ≈ 201 kW
• • Plant duty = 201 × 1.20 ≈ 242 kW
• • Equivalent plant duty ≈ 68.8 TR or 826,000 BTU/h

The live model then applies the selected freezer-type cost factor and electricity tariff to this same 242 kW planning duty.

Limitations

• • Product enthalpy and cycle time are category-level assumptions; formulation, packaging, geometry and airflow materially affect freezing time.
• • The CAPEX factor excludes civil works and cannot represent every country, refrigerant or automation scope.
• • Supplier selection requires a product freezing curve, design ambient, evaporating condition, fan power and guaranteed throughput test.

Illustrative planning result only. Confirm the final design, duty, equipment selection and performance with a qualified refrigeration engineer and supplier quotation.