Published 14 October 2026 · Source-linked research prepared with AI assistance. Proposed services require an agreed scope and qualified delivery team.
The simplified calculation
At steady state and with negligible drift and other losses: evaporation = makeup × (cycles − 1) ÷ cycles. Target blowdown = evaporation ÷ (target cycles − 1). Target makeup = evaporation + target blowdown. Gross savings use the change in makeup multiplied by the entered marginal water/sewer rate.
What the model leaves out
The screen holds evaporation demand constant and excludes changes in energy, treatment chemicals, maintenance, testing, financing and residual losses. Real towers may not satisfy these assumptions. Water quality and equipment requirements limit cycles. This is a comparison tool, not an operating instruction or a guaranteed payback.
Sources & further reading
- Best Management Practice #10: Cooling Tower Management ↗Current guidance checked 2026-10-14. The cycles example assumes suitable water chemistry and operation. Never recommend a higher setpoint solely from a calculator; water-treatment specialists must establish safe operating conditions.
- GSA Guidance—Alternative Water Treatment Systems for Cooling Towers ↗January 2020. Historical study costs, not current vendor quotes or generic market prices. Test-site metering differed; some baseline measures and most chiller-energy savings were not measured. Chemistry, maintenance, energy consumption, rates and location affect economics.