Tower cleaning and disinfection
- Scope
- An agreed cleaning and disinfection scope for the cooling tower.
- Before you enquire
- Tower access, condition and an agreed shutdown window.
- Quotation and scheduling
- The quotation identifies agreed work, tests and records. Price and scheduling depend on the system, access and any required downtime.
- Next step
- We reply within one working day, then confirm the scope and whether a site assessment is needed.
Cleaning removes what the biocide cannot reach. Sludge in the basin and biofilm on wetted surfaces shelter Legionella from chemistry that is otherwise working, which is why a tower can have a healthy chlorine residual and still fail a test. Gotech drains, desludges, cleans and disinfects the system, confirms it with a water test, and gives you a dated report for your file.
Dirt blows into an open cooling tower continuously. It settles in the basin as sludge, and micro-organisms colonise the wetted surfaces as biofilm. Both are nutrient and both are shelter — biofilm in particular protects bacteria from biocide, and amoebae living within it act as hosts in which Legionella replicates.
This is why dosing alone does not solve a biological problem. If the biocide cannot physically reach the organism, the dose is irrelevant. The EMSD Code of Practice requires cleaning, desludging and disinfection as part of operation and maintenance for exactly this reason.
What the clean includes
- Drain and desludge the basin — the single biggest reservoir of nutrient and bacteria
- Clean the fill, drift eliminators and wetted surfaces
- Disinfect the whole system, not just the visible parts
- Check the drift eliminators — they are the aerosol control, and a damaged one puts your problem into the air
- Confirm with a water test that the clean achieved what it was supposed to
- A dated report and photographs for your compliance file
What happens on site
- Plan the shutdown around your operation. In a mall or hotel that usually means outside trading or peak hours.
- Isolate and drain the system safely.
- Physical clean — remove sludge and deposit from the basin, clean fill and wetted surfaces.
- Disinfect to the Code of Practice, at the concentration and contact time the job requires.
- Flush, refill and re-establish the treatment programme.
- Test and report — a laboratory sample confirming the result, and a dated record of the work.
Scale on the fill? That is a different job
Routine cleaning removes sludge and disinfects; it does not dissolve hardness scale. If the fill is hard, pale and crusted, it needs acid cleaning: the descaler is recirculated through the tower for 4 to 6 hours, then neutralised and rinsed.
Why it matters
A clean without a diagnosis buys you a few months. If the tower fouled because the dosing failed, or because pH drifted, or because the drift eliminators are damaged, the count comes back — because the cause never left. We look for the reason, not just the symptom.
What it costs to get this wrong
A tower that is not cleaned on schedule costs you in three directions at once: fouled surfaces waste energy continuously, sludge accelerates under-deposit corrosion beneath the deposit where you cannot see it (see metal corrosion in water systems), and the biological risk builds until a sample catches it. At 1,000 cfu/mL or above that becomes a statutory notice and emergency decontamination — which costs more than the cleaning you deferred, and lands on your desk with a deadline attached.
Common questions
How often should a cooling tower be cleaned?
It depends on the tower's use, condition and environment. The EMSD Code of Practice requires cleaning, desludging and disinfection as part of routine operation and maintenance — commonly at least twice a year, plus whenever a test result or inspection calls for it (see how often should a cooling tower be cleaned?). We set the schedule from the tower's actual condition.
Do you have to shut the system down?
Yes — a proper clean means draining the basin, so the tower is offline for the work. We plan it around your operation. For a mall or hotel that usually means working outside peak hours.
My test came back high. How fast can you clean it?
Act promptly under your site incident procedure and any EMSD notice. Contact the responsible duty person and a qualified contractor to arrange the required sampling, emergency decontamination and follow-up tests. Preserve reports and records without delaying required action. See urgent help and availability.
Is disinfection the same as cleaning?
No, and the distinction matters. Disinfection kills organisms; cleaning physically removes the sludge and biofilm that shelter them. Disinfecting a dirty tower gives a poor result, because the chemistry never reaches what it is aimed at.
How much does cooling tower cleaning cost in Hong Kong?
It depends on the tower's condition and the work it needs, so every job is quoted individually in writing after a free site visit and assessment. Tell us about the tower by phone or WhatsApp and we will reply within one working day. We then agree the assessment and quotation timing — no obligation.
Scope and records
The agreed quotation defines the work, analysis, deliverables and schedule.
View a blank service-record templateNeed a tower cleaned?
Scheduled or urgent — tell us the tower and we will quote it.