Air Handling Units

Impeccable Hygiene and Outstanding Room Conditions

Hygiene in the pharmaceutical sector is a self-evident prerequisite to the quality of pharmaceutical products. Avoiding pathogens transmitted through the air is top priority. A hygienically impeccable and comfortable room climate is essential during development or production processes in the pharmaceutical sector. Air handling systems are, therefore, indispensable for reducing or avoiding airborne pathogens.

AHUs in cleanrooms performs the following basic functions:

  • Control airborne particles, dust and micro-organismen - Thru air filtration using high efficiency particulate air (HEPA) filters
  • Maintain room pressure (delta p) – Areas that must remain cleaner than surrounding areas must be kept under a positive pressurization. Therefore the AHU must provide more air into the cleaner space than is mechanically removed from that same space.
  • Maintain space moisture (relative humidity) – Humidity is controlled by cooling air to dew point temperatures or by using desiccant dehumidifiers. Humidity can affect the efficacy and stability of drugs and is sometimes important to effectively mould the tablets.
  • Maintain space temperature – Temperature can affect production directly or indirectly by fostering the growth of microbial contaminants on workers.

Air handling units by robatherm are especially designed to minimize the introduction, generation and retention of particulate and microbial contaminations in pharmaceutical cleanrooms.

Classification of clean rooms

Cleanroom classifications are established by measurement of the number of particles 0.5 micron and larger that are contained in 1 m³ or 1 ft³ of sampled air.

Cleanrooms can be classified in accordance to the US and European Guideline, where Class 100 is equivalent to Grade A and B, Class 10,000 to Grade C and Class 100,000 to Grade D.

At Rest: State of cleanrooms is the condition where the production equipment is installed and operating but without any operating personnel.

|2 In Operation: State of cleanrooms is the condition where the installation is functioning in the defined operating mode with the specified number of personnel working.

All pharmaceutical facilities belong to one or other class of cleanroom. The following table gives the requirements according to the application.


  • Rigid frame work
  • Anodized aluinium profiles
  • High density CFC free puf filled panels.
  • Galvanized steel channel base
  • Corrosion free insulated condensate drain pan
  • Vibration-free noiseless performance
  • Weather proof light, limit switch, view glass
  • Thermal break profiles.
  • Different stage filter sections
  • Imported centrifugal fans
  • Inbuilt covings


  • Floor mounted, double skin vertical, ceiling suspended ductable and special purpose AHU's are available.
  • 500 to 100,000 CFM capacity
  • Inner panels made out of stainless steel/ Aluminium/ pre coated/ powder coated sheets.
  • Single skin and ventilation units are available