Air coolers for sites without cooling water.

When air beats water

Water cooling needs a cooling tower or seawater system, chemical treatment, blowdown and make-up water. Air cooling needs only fans and power. It is usually the better choice when water is scarce, when the process outlet temperature can sit well above the hottest air temperature, or when the site is remote.

How an air cooler works

The hot process fluid flows through finned tubes in a bundle. Fans move air across the fins and carry the heat away. In a forced-draft cooler the fans sit below the bundle and push air up. In an induced-draft cooler they sit above and pull it through, which spreads the air more evenly and reduces hot-air recirculation. Air coolers for refineries and gas plants are built to API 661 (ISO 13706).

Designing for the Gulf summer

• Design air temperature: pick it from site weather data, often 45 to 50 °C, not a generic value. Every degree changes the size of the cooler.
• Approach temperature: the closer the outlet must get to the air temperature, the larger and costlier the unit.
• Fins and tubes: choose fin types that resist sand, salt and high skin temperatures, such as embedded G or extruded fins.
• Fans and control: variable pitch fans or variable speed drives save power in winter and at night.
• Layout: keep coolers away from hot exhausts and leave room for clean air to reach the fans.

What to send for a thermal design

Send the fluid, flow, inlet and outlet temperatures, allowable pressure drop, design pressure and temperature, the site design air temperature and any noise limit. Each design is rated in HTRI before fabrication.

Our partner Spiro-Gills Thermal Products has built air coolers since 1946 for more than 100 countries.

Forced-draft air coolers →   Induced-draft air coolers →