Avoid locating the air-cooled exchanger too close to buildings or structures in the downwind direction. Hot air venting from the air cooler is carried by the wind, and after striking the obstruction, some of the hot air recycles to the inlet. An induced draft fan with sufficient stack height alleviates this problem, but locating the air cooler away from such obstructions is the best solution.
An air cooler with forced draft fans is always susceptible to air recirculation. If the air cooler is located too close to the ground, causing high inlet velocities relative to the exhaust air velocity leaving the cooler, the hot air recirculation can become very significant. Forced draft coolers are preferably located above pipe lanes relatively high above the ground. Induced draft coolers are less likely to experience recirculation because the exhaust velocities are normally considerably