Modelled from the manufacturer's published data — not verified by EVAPCO. Source: EVAPCO ATWB Engineering Data & Dimensions — the model's own row (nominal tonnage, airflow in CFM, fan motor and its printed count, height and length) and the sheet's own note: nominal tonnage is 3 gpm per ton at 95 °F entering water, 85 °F leaving and a 78 °F wet bulb. Its second condition is EVAPCO's own CTI 49-point table, which the model reads at 0.22 K RMS over 45 945 points (docs/evapco-cti-source.json). The figures below come from this model run against that data; the manufacturer has not reviewed them. Are you EVAPCO? Claim this page.
CTI STD-201 (validation C13F-09R12) ✓ verified — this model is named in the certification programme's own public register. It certifies the manufacturer's machine against their published ratings; it says nothing about the model of it that runs here, which is validated separately.
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EVAPCO's 24-4N18 — a ATWB closed-circuit cooler, 870 nominal tons (3825 kW): rated to cool 2182 USGPM of process fluid from 102 to 90 °F at a 75 °F entering wet bulb on 123.0 m³/s of air, the maker's own printed airflow, and drawn at those flows with an induced-draft fan on the leaving air, pulling through the fill. The process fluid runs inside a coil under the spray — the evaporative wet-coil model, its two conductances split as the range's own coil volumes say. The model derives the machine's NTU from that one certified point, so it reproduces the rated leaving process fluid exactly and predicts nothing else — one point per model is an input, not a validation. Modelled from the manufacturer's published data — not verified by EVAPCO. Published as an example; the figures below are solved from this model.
Example2869–4781 kW coolingEUExample system. Published by HVAC Builder to show suppliers what their own page looks like. There is no company behind it and it is not a product offer — the specification is generic and the performance is solved from the model on this page.
Solved from this example's own model each time the page loads — the same numbers a supplier's page shows for their machine.
| Component | Kind | Duty |
|---|---|---|
| 24-4N18 fill | wetPack | -3784.7 kW |
| 24-4N18 fan | fan | -59.7 kW |
| 24-4N18 tower-loop circulator | pump | — |
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