How the estimate works.
The estimator answers one question: how much energy do the fans on a cooling tower or an evaporative air cooler use in a typical year, in your city? Here is how we get the number.
Weather
We use the hourly weather NOAA recorded at each city’s airport station from 2011 to 2024. For 2030 and 2050 we shift that weather by the change eight climate models project for the area. The estimator shows the middle case; the full report adds the high case.
Cooling towers
We size a standard tower for your tons at a common design point: cold water 7 °F above the muggiest hour of a normal year, 10 °F of cooling. The fill is a standard film fill, from a published correlation. For every hour of the year we work out how hard the fans have to run to keep the cold water on target, and add it up.
Evaporative air coolers
Same idea, for a standard 12 inch cellulose pad, using a manufacturer’s published curves for pressure drop and cooling. The fans move the air the building needs; we add up the fan energy over the year.
What it leaves out
It models standard equipment, not our fill and not your exact site. It assumes a steady load all year and typical fan efficiency, and it does not count pumps or the chiller. Treat the result as a starting point for a conversation, not a quote.
Data credits
Weather: NOAA National Centers for Environmental Information, Integrated Surface Database (ISD-Lite), 2011 to 2024, public domain.
Future climate (2030 and 2050) uses CMIP6 model output from eight models: ACCESS-CM2 (CSIRO-ARCCSS), CanESM5 (CCCma), EC-Earth3-Veg-LR (EC-Earth-Consortium), GFDL-ESM4 (NOAA-GFDL), INM-CM5-0 (INM), MIROC6 (MIROC), MPI-ESM1-2-HR (MPI-M, DWD, DKRZ) and MRI-ESM2-0 (MRI), licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Intrnls reduced the output to monthly change factors and applied them to station weather. The data were modified. We acknowledge the World Climate Research Programme, which, through its Working Group on Coupled Modelling, coordinated and promoted CMIP6. We thank the climate modeling groups for producing and making available their model output, the Earth System Grid Federation (ESGF) for archiving the data and providing access, and the multiple funding agencies who support CMIP6 and ESGF.
Fill: Kloppers, J.C. (2003), A critical evaluation and refinement of the performance prediction of wet-cooling towers, PhD dissertation, University of Stellenbosch. Psychrometrics: psychrolib, Meyer and Thevenard (2019).
Every result is a modeled estimate. Preliminary, for discussion purposes and illustrative only. Not engineering data. No warranty provided.