Plant optimization calculator · Updated 17 September 2026
Chiller Fouling Index Calculator — Approach Rise & Efficiency Penalty
Trend condenser or evaporator approach against a clean baseline and pair the approach rise with measured kW/ton change to quantify a practical fouling-performance signal.
Inputs
Live results
- Approach rise 2 K
- Approach ratio 2
- kW/ton penalty 12.727273%
- Combined trend index 25.454545
Formula
Approach rise=Acurrent−Abaseline; efficiency penalty=(kW/ton current ÷ baseline−1)×100.
Worked example
Approach rising from 2 K to 4 K while kW/ton rises from 0.55 to 0.62 flags deterioration.
Assumptions and limits
- This is a trending index, not a refrigerant-side fouling-factor calculation.
- Compare similar load, flow and entering-water conditions.
FAQs
What does this Chiller Fouling Index Calculator calculate?
Trend condenser or evaporator approach against a clean baseline and pair the approach rise with measured kW/ton change to quantify a practical fouling-performance signal.
Can I use this for a final design?
Use it for screening, diagnostics and opportunity sizing. Validate final design against measured plant data, OEM limits and applicable standards.
Why does the calculator show intermediate results?
Intermediate engineering quantities make bad inputs and unrealistic assumptions easier to spot before a decision is made.