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Plant Engineering Calculator

Updated Sep 18, 2026

Chiller Heat Rejection Calculator — Cooling Load + Compressor Power

Calculate condenser heat rejection as evaporator cooling load plus compressor input, with kW and refrigeration-ton outputs and rejection ratio.

Live calculationWorking shownPrivate in browser

Inputs

Results

Heat rejection 1200.0 kW
Heat rejection 341.2 TR
Rejection ratio 1.200
COP 5.00
More actions

Shared links reopen these inputs. Recent and saved calculations stay in this browser unless you clear site data.

Formula

Qreject=Qcooling+Pcompressor+Qaux.

Your calculation, step by step

These steps use the values currently entered above so the result can be checked independently.

  1. 1.Condenser heat rejection = cooling load + compressor input + auxiliary heat = 1000.00 + 200.00 + 0.00 = 1200.000 kW.
  2. 2.Thermal refrigeration-ton equivalent = 1200.000 ÷ 3.5168525 = 341.214 TR.
  3. 3.Rejection ratio = 1200.000 ÷ 1000.000 = 1.2000.
  4. 4.Chiller COP from the same cooling/power snapshot = 1000.000 ÷ 200.000 = 5.0000.

How to use this calculator

  1. Enter measured or design values using the units shown beside each field.
  2. Review the live results and the substituted calculation steps before using the estimate.
  3. Check the assumptions below, then continue to a related calculator when the next engineering decision needs another model.

Worked example

A chiller delivering 1,000 kW cooling at 200 kW input rejects about 1,200 kW at the condenser before any separately entered auxiliary heat.

Assumptions and limits

  • Steady-state energy balance excludes auxiliary heat unless explicitly added.
  • Use measured simultaneous load and power for operating diagnostics.

How to interpret the result

Treat the primary result as an engineering screening value, then use the secondary outputs to understand scale, energy or operating impact. Confirm site measurements, equipment limits and applicable standards before making a design or control change.

Questions engineers ask

Why is condenser heat rejection cooling load plus compressor input?

At steady state the condenser rejects heat absorbed at the evaporator plus the electrical work converted to heat in the refrigeration cycle. Optional auxiliary heat can be added when it crosses the same condenser boundary.

Why show a heat-rejection ratio?

Qreject/Qcooling makes the condenser/tower burden relative to delivered cooling visible. The ratio increases as compressor input rises for the same cooling load.

What data should be simultaneous?

Cooling load and compressor kW should represent the same operating interval. Combining peak cooling from one time with average power from another creates a misleading condenser balance.

Continue the calculation

Use the next calculator in the same engineering workflow instead of restarting from search.

chiller kw per tonchiller condenser approachcooling tower heat rejection
Methodology. MAXScanner shows the governing formula, entered values and calculation outputs so the estimate is auditable. The calculator is a screening aid; assumptions and equipment-specific limits remain part of the engineering review.