R-Pro › Field cases › Cooling towers
Legionella Positive Detection — Hygiene Management Failure
Likely causes
No biocide dosing or residual chlorine below 0.2 ppm
Check: Measure residual chlorine — below 0.2 ppm = immediate treatment needed; ATP luminescence test for microbial load
What to do: Immediately shut down and notify authorities → shock chlorination (5–10 ppm residual 24 h) → high-pressure clean all fill, pipes, water pans and physically remove biofilm
Water temperature lingering in 25–45°C range — optimal Legionella growth zone
Check: Review water temperature log — identify time spent in 25–45°C range; monitor during low-load periods
What to do: Install continuous ClO₂ dosing system — maintain 0.3–0.5 ppm residual → restart only after 2–4 consecutive weeks of negative tests
Legionella multiplies 10x within 24 hours at 35–37°C — weekly residual chlorine checks are mandatory.
All 565 cases work offline in R-Pro, with error codes for 62 brands and P-T data for 108 refrigerants.
Open R-Pro →Related cases
- Insufficient Cooling Capacity During Peak Summer Heat
- Fill Deterioration/Blockage — Reduced Heat Exchange Efficiency
- Spray Nozzle Blockage/Misalignment — Uneven Water Distribution
- Insufficient Fan Airflow — Belt Slip / Blade Pitch Misadjustment
- Condenser/Fill Scale Buildup — Reduced Heat Transfer
- Steel Structure/Pipe Corrosion — pH Management Failure