A biodispersant is described as low-foaming: why does the cooling tower still foam?

First confirm the test conditions behind a low-foam claim

When requesting data, clarify test water, temperature, agitation and assessment time, and distinguish raw-material descriptions, formulated-product trials and site operating records. Guardian’s specific biodispersant formulations include surfactant and foam-control functions, but these examples do not establish that every similarly named product is low-foaming. If information contains only a marketing term without test limits, treat it as a property awaiting validation, not an unconditional purchasing guarantee.

Use water samples representative of the site

Compare fresh makeup water, actual recirculating water and samples from abnormal periods, retaining information on other treatment chemicals and contaminants. Good clear-water results but abnormal recirculating-water behavior indicate a need to investigate water quality and compatibility rather than immediately blaming insufficient active content. Identify sources in systems affected by oil, cleaning-product ingress or returning additives. A biodispersant cannot indefinitely compensate for unidentified ongoing contamination.

Focus on how the condition subsides over time rather than a single photograph

Under a professionally approved test method, record foam formation, changes after agitation stops and repeated-cycle behavior. Photographs need timestamps and scales because similar apparent heights can come from different containers. Site observations should also establish whether foam reaches makeup-water controls, level instruments or exhaust areas. Without equivalent agitation and temperature conditions, do not rank two products for low foaming or directly extrapolate operating costs.

Do not conceal compatibility problems with additional defoamer

If operation can be maintained only after adding another chemical, treat it as a new combined program and review filtration, heat transfer and biological-control objectives again. Additional antifoam may affect trial interpretation; results can no longer be attributed solely to the original dispersant. Distinguish contributions from incoming contamination, formulation, dosing equipment and site conditions before deciding whether to change purchasing requirements, improve management or select another formulation.

Create a meaningful purchasing comparison table

For each candidate, record water source, temperature, dynamic test method, foam formation and decay, dispersing performance and material restrictions, retaining untreated and current-product controls. Attach photographs alongside original records so suppliers can review evidence rather than receiving only ‘severe foaming.’ Selection should meet both dispersion objectives and actual equipment requirements; ‘low foam’ is only a starting point for assessment.

The site can also record whether foam affects level signals, spraying or return flow rather than retaining only its visible height. A sample with a lower foam layer may still fail to meet equipment needs if the foam dissipates more slowly or enters critical areas more readily. Define these impacts as screening questions in advance so low-foam evaluation becomes evidence directly relevant to operation rather than a marketing phrase.

Explore further