Pneumatic Filter Cleanrooms

HEPA/ULPA filter

Cleanrooms are highly controlled environments and the quality of the air must meet very strict standards. These standards are required for a large range of industries for example, healthcare, food, pharmaceutical and electronics.

Within the cleanroom it is paramount that contaminants are not introduced from the external environment; equipment within the cleanroom do not generate contaminants; contaminants do not accumulate within the cleanroom and if contaminants do arise they are eliminated as far as possible and as quickly as possible.

Airborne particles generated within the cleanroom as solids which suspend within the air. They are defined as bodies having physical boundaries in all directions; a diameter ranging from 0.001micron – 100 micron and have liquid or solid phase material characteristics.

Airborne particles are solids suspended in the air. For our purposes, particles are defined as bodies with:

  • Definite physical boundaries in all directions.
  • Diameters ranging from 0.001 μm to 100 μm.
  • Liquid or solid phase material characteristics.

These particles can come from (1) the environment, (2) people, (3) tools, (4) fluids and (5) the product being manufactured. The ambient air outside in a typical city environment contains 35,000,000 particles per cubic meter, 0.5 μm and larger where as in ISO Class 5 cleanroom the limit is 3,520 ≥0.5µm in diameter. So, this shows the dramatic reduction in particles. When designing the cleanroom, it is these particles that we are trying to eliminate through cleanroom design and management.

Modular Cleanroom Benefits

  • Modular Construction
  • Quick Assembly Time
  • Versatility
  • Reconfiguration
  • Airflow Control
  • Inexpensive Modifications

One of the components in enabling the reduction in particles is the use of high efficiency filters

The stringent standards cleanrooms have to meet detailed in BS 14644 are maintained using various components one being the use of filters. These filters can be either “High efficiency particulate air (HEPA”) or “Ultra Low Particulate Air (ULPA)”. These filters must conform and be certified to EN1822:2009 which is the regulation that governs them.

These filters are constructed of filter media which is the area of the filter that filters out the particles, sealants which create a leak-proof seal between the filter media and frame, a frame where the filter sits and a gasket which will prevent any air from leaking out. To qualify as HEPA by industry standards, an air filter must remove (from the air that passes through) 99.97% of particles that have a size greater-than-or-equal-to 0.3 µm and an ULPA filter must remove at least 99.999% of particles that have a size greater-than-or-equal-to 0.1 µm.

The HEPA filter or ULPA filter will then be housed within a Fan Filter Module (FFM) primarily within cleanroom on the ceiling. The number of these FFM are dependant on the size of the cleanroom and the ISO standard required. All air-handling systems within cleanrooms will also have pre-filters to remove gross contamination and protect the cooling coil and final filter from environmental conditions. As HEPA and ULPA filters only remove particles if the removal of odour and hazardous & corrosive gases are required it is necessary to include activated carbon filters into the design of the cleanroom.

Cleanroom Design, Build & Validation

  • Budgeting and planning
  • Engineering, design & layout
  • Airflow and filtration design
  • Construction and Installation
  • Full Certification of our product
  • Industry-specific equipment installation
  • Validation

DOP testing to Ensure Secure Environment in a Cleanroom

It is vital that the HEPA or ULPA filters within the cleanroom, be it part of the cleanroom or within the equipment within the cleanroom are functioning correctly. In order to ascertain this filter integrity testing or Dispersed Oil Particulate (DOP) testing is an assessment executed to determine integrity and performance of an installed Ultra Low Penetration Air (ULPA) filter or a High Efficiency Particulate Air (HEPA) filter.

As these HEPA or ULPA filters are prone to damage it is paramount that this DOP test is not only carried out at regular intervals, but also when equipment is moved. Using a cloud of dispersed oil particulate as an aerosol, DOP testing involves releasing a high concentration of the aerosol into the airstream, upstream of the filter. The filter face is then scanned using a photometer to measure the concentration of particles which have made their way through the filter. DOP filter testing provides assurances for all parts of the filter, including the seals and the housing of the filter.

Involving highly specific and technical guidelines to ensure consistent testing, as well as being a part of your regulatory obligations, the DOP testing for your specialist ventilation system should be carried out by professionally qualified engineers to avoid costly mistakes. We at Total Clean Air carry out all our DOP testing to BS ISO 14644-3: Test Methods B.6.2 Procedures for installed filter system leakage scan test with an aerosol photometer, using qualified, experienced engineers.

Carbon filter testing

It is also vital to have your carbon filters tested according to the current British and European standard BS EN 14175 this should be done annually or more frequently should your risk assessment highlight. We at Total Clean Air carry out all carbon filter testing to BS EN 14175-2:2003 which details all the suitable performance tests.

Contact us for a Customised modular cleanroom, HEPA/ULPA/Carbon installation, maintenance or validation.

At Total Clean Air, your contamination control requirements are our priority. Our proven expertise and CTCB-I certified engineers are available to discuss any requirements you have questions you may need to ask.

Are you ready to start a project with us? Give us a call today.

Phillip Godden

Phillip Godden is the Founder & Chief/Executive Officer at Total Clean Air.

Working Hours

  • Monday 08:00 - 19:30
  • Tuesday 08:00 - 19:30
  • Wednesday 08:00 - 19:30
  • Thursday 08:00 - 19:30
  • Friday 08:00 - 19:30