Coolers & Aftercoolers

All reference
Component

Heat exchangers that remove compression heat — intercoolers between stages, aftercoolers after discharge — to cut power, condense moisture, and protect downstream equipment.

Operating principle

Intercoolers cool air between compression stages (improving efficiency and lowering discharge temp); aftercoolers cool the final discharge to condense moisture (removed by drains/dryers) and protect piping and downstream equipment.

Components
  • Air-cooled fin/tube bundle or water-cooled shell/tube
  • Fan (air-cooled)
  • Cooling-water circuit (water-cooled)
  • Thermostatic valve (oil temp)
  • Condensate drain
Common issues
  • Fouled fins/tubes → high discharge temp, reduced capacity
  • Fan/motor failure → overheat trip
  • Cooling-water scaling/fouling → lost heat transfer
  • Thermostatic valve stuck → oil too hot or too cold
Maintenance
  • Clean fin/tube bundles on a schedule and on temp rise
  • Inspect fans, motors, belts
  • Water side: treat and descale per water quality
  • Drain condensate traps
Field tips
  • Each 10°F cooler discharge ≈ 1% energy saving (air-cooled)
  • An aftercooler removes ~70% of moisture mechanically — drains are mandatory
  • Water-cooled: monitor approach temperature to catch scaling early