Dry Cooler
Evaporative Dry Cooler
The dry cooler is intended for projects requiring year-round water conservation. It uses air-cooled, dry-bulb heat dissipation with a typical temperature difference of 7–8°C. At a fresh-air dry-bulb temperature of 28°C, the cooling-water outlet temperature is 35°C. Wet-film evaporative cooling is required during high-temperature periods to meet annual free-cooling requirements.
Discuss this productFeatures & technical specifications4 specification tables
| Climate / cooling requirement | Water availability | Recommended cold source |
|---|---|---|
| Low ambient temperature; year-round free cooling possible | Abundant | Closed or open cooling tower |
| Low ambient temperature; year-round free cooling possible | Scarce | Dry cooler |
| High ambient temperature; mechanical-cooling backup needed | Abundant | Chiller + cooling tower + plate heat exchanger |
| High ambient temperature; mechanical-cooling backup needed | Scarce | Air-cooled chiller |
| Design parameter | Primary side | Secondary side |
|---|---|---|
| Supply temperature | Recommended ≤35°C, considering local weather and required secondary supply; W45 or W+ allowed where cooling requirements permit | Recommended 40–48°C for energy efficiency; temperature and flow must meet liquid-cooled component requirements |
| Supply / return temperature difference | 6–10°C; ideal 8–10°C | 5–10°C; recommended ideal 6–8°C |
| Comparison item | Closed cooling tower | Evaporative dry cooler |
|---|---|---|
| Energy efficiency | Relatively superior | Relatively inferior |
| Footprint | Small | Large |
| Cost | Low | High |
| Annual water consumption | Approximately 1.8–2.0 L/(kW·h) | <0.5 L/(kW·h); varies by city |
| Peak 12-hour water usage | Relatively high | Relatively low |
| Suitable regions | Abundant water resources | Water-scarce regions; strict WUE limits |
| Year-round waterless operation | Not possible | Not possible; water needed during high outdoor temperatures, waterless operation possible at other times |
| Parameter | Source value |
|---|---|
| Heat-rejection basis | Air-cooled / dry bulb |
| Typical approach Δt | 7–8°C |
| Fresh-air dry-bulb example | 28°C |
| Cooling-water outlet example | 35°C |
| Year-round free-cooling design consideration | Outlet water no higher than 35°C |
| High-temperature operation | Fresh-air-side wet-film evaporative cooling required in source example |
Reference conditions & selection notes
- This source describes an evaporatively assisted dry cooler. It conserves water but is not waterless throughout the year; evaporative assistance requires water during hot weather.
- Outlet temperature, annual water use and need for mechanical backup depend on local meteorology and operating conditions.
- W45 and W+ are source designations; the source does not define them further.
Liquid Cooling Manual, pp. 21–23