Engineering calculator · Updated 17 September 2026
Chiller Evaporator Approach Calculator — Leaving Water vs Saturation
Calculate evaporator approach from leaving chilled-water temperature and refrigerant evaporating saturation temperature, with water-side range.
Inputs
Live results
- Evaporator approach 3 K
- Water-side range 5 K
- Entering-water to saturation span 8 K
Formula
Approach=LCHWT−Tevap,sat.
Worked example
7°C leaving chilled water and 4°C evaporating saturation gives 3 K approach.
Assumptions and limits
- Use saturation temperature from measured evaporator pressure.
- Compare trends at similar load and flow before diagnosing fouling or refrigerant issues.
FAQs
What does this Chiller Evaporator Approach Calculator calculate?
Calculate evaporator approach from leaving chilled-water temperature and refrigerant evaporating saturation temperature, with water-side range.
Is this suitable for final equipment selection?
Use the result for engineering screening and operating diagnostics. Confirm final selections against measured data, OEM curves and applicable codes.
Why are the assumptions explicit?
Plant results depend on reference conditions, pressure basis, efficiencies and measurement locations. Showing assumptions keeps the calculation auditable.