What EN 1822 Means for Cleanroom Entry Air and Critical Rooms

EN 1822 comes up whenever a project moves beyond standard HVAC filtration and into spaces where particle control really matters. For cleanrooms, laboratories, hospital support areas, pharmaceutical rooms and other controlled environments, the question is not just whether a filter fits the frame, but whether it is suitable for the required level of air cleanliness.

If you are specifying entry air or final filtration for a critical room, EN 1822 is one of the key standards used to define HEPA and ULPA performance. It helps buyers, contractors and facilities teams distinguish between everyday pre-filters and the high-efficiency filters used where particle capture needs to be tightly controlled.

What EN 1822 is used for

EN 1822 is a European standard that classifies and tests high-efficiency particulate air filters. It is most relevant where the filtration stage must perform at HEPA or ULPA level, rather than at the coarser ratings used for general HVAC systems.

In practical terms, EN 1822 is used to assess filters intended for:

• •Cleanroom supply or recirculation systems
• •Laboratory HVAC systems with tight particulate control needs
• •Critical rooms and controlled environments
• •Pharmaceutical and electronics manufacturing spaces
• •Air handling systems where final-stage filtration is required

The standard is important because it focuses on actual filter performance, not just frame size or media type. That makes it useful when you need to compare like with like.

Why standard HVAC filters are not always enough

Standard HVAC filters play an important role in protecting equipment, improving system cleanliness and managing everyday dust loading. In many commercial buildings, a staged filtration approach is enough: a pre-filter first, followed by a finer secondary filter where needed.

But cleanrooms and other critical rooms usually need a higher level of control than a typical building system. That is where HEPA or ULPA filters come in. These filters are designed for much finer particle capture than standard panel, bag or pleated filters.

Common classifications used in Australia still include G3/G4 and F5-F9 terminology from EN 779, although that standard has been superseded by ISO 16890. Those ratings are useful in general HVAC work, but they do not directly convert to EN 1822 HEPA or ULPA classes, and they should not be treated as interchangeable.

For project planning, that means the filter specification must match the room purpose, the air handling design and the cleanliness target. If you are unsure which stage does what, it is worth reviewing the system design with the mechanical services engineer or building owner, especially where AS 1668.2:2024 applies to the broader ventilation requirements.

Understanding HEPA and ULPA classes under EN 1822

EN 1822 is often discussed in terms of filter classes. For buyers and contractors, the key point is that the class tells you how the filter performed in the test method used by the standard.

For HEPA filters under EN 1822:

• •H13 is at least 99.95% efficient at the most penetrating particle size (MPPS)
• •H14 is at least 99.995% efficient at the MPPS

ULPA filters are used where even finer particulate control is needed. These are generally selected for more demanding environments, but the exact class should always be chosen to suit the room design and process requirements.

A few practical points matter when reading an EN 1822 specification:

• •The MPPS is important because it reflects the particle size the filter is least efficient at capturing
• •The rating applies to the tested filter, not to the entire system by default
• •Good filter installation, sealing and housing design are essential for the filter to perform as intended

That last point matters because even a correctly rated filter can underperform if there is bypass leakage around the frame or in the housing.

What to look at when specifying filters for critical rooms

When you are selecting filters for a cleanroom entry system or another controlled space, the filter class is only one part of the decision. You also need to consider the physical and operational details of the installation.

Useful questions to ask include:

• •What is the room or process trying to control?
• •Is the filter part of a final stage, a pre-stage, or both?
• •What size, depth and frame type does the housing accept?
• •Is the system designed for side access, front access or a terminal housing?
• •What pressure drop can the fan or air handling system handle?
• •Is the room using terminal HEPA units, bag-in/bag-out housings or another arrangement?

For replacement work, accurate measurement matters as much as the filter class. If you are matching an existing unit, use the old filter dimensions, housing measurements and product details carefully. Our guide on how to measure an air filter is a useful starting point for replacement planning.

If the project is new or the existing housing is no longer suitable, it may be better to use custom air filters rather than compromise on fit.

Maintenance, pressure drop and replacement planning

Critical room filters are not selected once and forgotten. Their condition should be checked as part of the site’s maintenance plan, with inspection frequency depending on the system, site conditions and dust load.

Where gauges or monitoring points are fitted, pressure drop should be observed so the filter can be changed or checked at the right time for the application. The filter and equipment manufacturer instructions should always be followed.

A few maintenance points are worth keeping in mind:

• •Keep housings, seals and access points in good condition
• •Check that the filter seats correctly after installation
• •Watch for loading changes if nearby works or process dust increases
• •Confirm whether the filter is intended for single-use replacement or whether some filters are designed to be washable - check the product instructions

For ongoing support, filter servicing and commercial filter servicing can help keep the system in good order without guessing at changeout timing.

Choosing the right supplier for cleanroom and laboratory work

Cleanroom and critical-room projects often involve more than just ordering a part number. You may need assistance with sizing, compatibility, sealing method, access arrangement or the practical difference between a general HVAC filter and a true HEPA or ULPA unit.

That is where it helps to work with a supplier who understands both product selection and replacement realities on site. Total Air Filtration is a family-owned air filter manufacturer and supplier in Hillcrest, Brisbane QLD, established 2009.

We supply filters for controlled environments, general commercial systems and specialised applications, and we can help identify whether a standard product from our products is suitable or whether a made-to-order solution is needed.

If your project has a specific room classification, mechanical design or access limitation, it is often best to discuss it before ordering. You can also review the types of work we support across industries we supply.

Need help selecting EN 1822 filters?

If you need the right filter for a cleanroom entry system, laboratory, or other critical room, Total Air Filtration can supply or make the right filters for the job. Call 07 3800 3448 or request a quote to discuss your requirements.