Cascade Refrigeration Cycle Calculator
Below about −35°C evaporation, single-stage compressors struggle: pressure ratios climb, discharge temperatures become dangerous, and COP collapses. Cascade systems couple two separate cycles through a cascade heat exchanger, letting each stage run in its efficient zone.
The full cascade tool computes both stages with real properties — evaporating temperature, condensing temperature, stage overlap, and intermediate temperature — and returns system COP plus both stages' state points.
Below about −35°C evaporation, single-stage compressors struggle: pressure ratios climb, discharge temperatures become dangerous, and COP collapses. Cascade systems couple two separate cycles through a cascade heat exchanger, letting each stage run in its efficient zone.
Unlock the full cascade calculator — free account →Frequently asked questions
When is a cascade system better than a two-stage system?
Cascade excels below roughly −35°C evaporation or when the low-stage refrigerant must stay above atmospheric pressure (e.g. R23 with R134a/R410A high stage). Two-stage economized compressors are usually preferred for moderate low-temp work.
Which refrigerant pairs are common in cascade?
R134a or R410A high stage with R23, R508B, or CO2 low stage. CO2 low-stage cascades (R744/R134a) are widely used in supermarket refrigeration.
How is cascade COP computed?
Each stage is solved as its own vapor-compression cycle; the heat rejected by the low-stage condenser equals the high-stage evaporator load through the cascade exchanger. System COP = total cooling ÷ total compressor power across both stages.
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