Operating Theatre

Laminar flow operating theatre systems provide maximum protection from contaminations and other filtration systems.

Recirculation Modules


An operating theatre is provided with preconditioned air by a central air handling unit (AHU). Nowadays, most hospital ventilation systems operate with a mixture of fresh and recirculation air. For operating theatres or minor surgery rooms to be upgraded or renovated, recirculation modules are an excellent alternative. Because many older facilities have insufficient space for bigger AHU’s and ducts etc, the recirculation module can be installed in either the ceiling (Optivent) or the wall (Optiwall). Here, the recirculation module will supply the recirculation air and the existing or new AHU will supply the fresh air portion.

Recirculation modules consist of three parts:

  • Plinth – where the height of the unit will be adjusted and fixed
  • Suction Chamber with installed Fluff Separator, Fine Dust Filter (F7), Control box as well as cooling battery
  • Ventilation Chamber with built-in silencers, fan and damper

MANN+HUMMEL offers Optivent-CG and CG³-US for installation in the intermediate ceiling and Optiwall-CG and CG³-WUK for wall fitting.


  • No need for additional bigger ducts and AHU
    Upgrade existing systems without major works and space requirement
  • Exhaust air (recirculation air) positioned in close proximity to the floor
    Defined unidirectional air flow
  • Easy to use control system 
    Simplifies achieving exact air volumes
  • Recirculation modules can be positioned outside of the operating theatre
    Reduces noise level
  • Service of the wall recirculation modules outside of the OT
    No additional cleaning necessary 
  • Minimal fresh air part
    Reduced Energy consumption
  • All acceptance tests fulfilled
    Including requirements of all international standards