Air Coolers



Air Cooled Heat Exchanger’s also known as Fin Fan heat exchangers are typically used in applications where water is not available or the desired process outlet temperature can be achieved given the maximum ambient temperatures.  Also, air cooled equipment can be a more simple solution against water cooled because in water cooled systems typically there is also a need for more pumps, piping, central chiller or cooling towers increasing the operating cost and maintenance of the system.

 Air Cooled Heat Exchangers are used in a wide variety of applications. They can be used as lube oil coolers, water and glycol coolers, inter/after coolers on compressors, jacket water cooler, engine radiators, belt guard after-coolers, hydraulic oil coolers (both stationary and mobile), closed loop cooling systems, and condensers.

 With our vast knowledge and expertise in a wide range of industries and markets we can help put you in the most cost effective and efficient option available.

 Fan Driven units are shipped with electric motors suitable for outdoor applications.  Alternate motors are available upon request, i.e. hydraulic motors and air motors. 

KASRAVAND can provide equipment with copper, carbon steel, or stainless construction including the headers, tubes and fins.

The air-cooled heat exchangers are mostly used when the plant location and the ambient conditions do not allow an easy and economic use of other cooling systems.

The most evident advantages of air-cooled heat exchangers are:

  • Prevention of thermal and chemical pollution of cooling fluids (closed circuits)
  • Flexibility for any plant location and plot plan arrangement (installation over other units)
  • Reduction of maintenance costs
  • Easy installation by bolted assembly
  • Lower environmental impact than shell and tube heat exchangers thanks to the elimination of an auxiliary water supply 

 KASRAVAND provides complete aircooler units including tube bundle assembly, motor-fan groups, structure, access ladders and walkways. Typical arrangement can be 

  • forced draft
  • induced draft
  • air-recirculation unit 

KASRAVAND supplies also Pre-assembled modules. 

Typical components include headers, finned tubes, and fan assembly.  

Forced draft 

Allows easier maintenance of the fans.
Fans deliver air at ambient temperature with consequent higher efficiency. 

Induced draft 

 The plenum chambers are mounted on top of the bundle and protect the finned surface against wind, rain, snow and partially hail. The location of the fans also ensures an optimum air distribution, limits air recirculation and allows maintenance at a lower level.  

Recirculated / Winterization 

This feature is recommended for special process (hydrate prevention..) and cold climates where it is advisable to provide warm air recirculation to prevent freezing or pouring. The recirculation may be achieved by mean of louvers, steam coils and variable fans.

Pre-Assembled modules 

The long construction time needed for the installation of the plants as well as the lack of manpower and its increased cost, have prompted the introduction on the market of pre-assembled units. These units are expressly designed for safe transport and easy installation on the plant. On demand they can be shop tested before delivery.

The air cooled tube bundle cover the complete range of: 

  • Metallurgies from low alloy and carbon steel, stainless steel, duplex and super-duplex stainless steel, nickel alloys and titanium.
  • Plugs, cover or high pressure manifold header boxes design.
  • Extruded, L-footed or Embedded aluminum tubes fins. 

As well as common configurations we can also supply additional features like: 

  • Finite element analysis header box verification under severe load cases including nozzle to header join.
  • High pressure design up to 700 Bar(g) made by forgings including tube ends to manifold box IBW (Internal bore welding) joint.
  • Plug type header box local tube-ends to tube sheets welded joint PWHT through plug hole.
  • Low noise emission design (76 db(A) power level) with low noise fan and noise damping panels.
  • Resonance vibration free design by spectral analysis check
  • Completely pre-assembled modularized units.
  • Winterization arrangement made of intake louvers, by-pass louvers, exhaust louvers and enclosure.
  • Design and manufacturing of frequency converter cabinets and container units comprehensive of MV/LV transformers, MCC, PLC, frequency converters and cooling. 

Technical data:

  • Max size and weight: Up to 18m fin tube length, up to 4.4m bundle width, 30 ton
  • Design pressure and design temperature:
  • Up to 613 bar, up to 400°C
  • Motor range:  5kW to 45kW with frequency converter and complete cabinets
  • Fan size:  1.8 - 5.5m  

Materials of Construction

  • Carbon Steel with or without NACE requirement and / or HIC testing.
  • Chromium Molybdenum Alloy Steel.
  • Stainless Steel Alloys.
  • Duplex Stainless Steel Alloys.
  • Incoloy.
  • Welding procedures are already established for Inconel and Titanium materials and hence capability exists for this metallurgy too.



Fine control of process outlet temperature is achieved by the individual
or combination of the following methods of control.

  • Auto control of fan blade angle.
  • Auto control of louver blade angle.
  • Auto control variable speed drive system for fan speed control.
  • Combination of the one or all of the above options wherever complete winterization is required with internal or external air recirculation arrangement along with steam coil with options as per system A to D of API 661.