Compliance-grade air filter production and testing infrastructure used to support aviation cabin and cleanroom supply-air projects.

EN 1822 is the European classification standard that grades HEPA and ULPA air filters by their particle-removal efficiency at the Most Penetrating Particle Size (MPPS) — the particle size at which a given filter performs least well. That single testing principle is what allows an aviation buyer and a cleanroom buyer to compare filters from different suppliers on the same basis, and it is also the reason a filter described only as “HEPA” cannot be accepted as compliant with a specification that calls for a defined class.

For aviation cabin air, the class most often specified is H13, inside the HEPA band. For cleanroom supply air, the classes most often specified are U14 and U15, inside the ULPA band. The two bands belong to the same standard but answer different contamination-control requirements: EN 1822 sets H14 at 99.995% efficiency at MPPS (MANN+HUMMEL Air Filtration, EN 1822 standards reference).

This guide explains how the EN 1822 grade decision is actually made for aviation and cleanroom filtration, what a buyer should verify before approving a supplier, and how the comparison data published by Henkaes positions its filters against common alternatives. Every performance figure quoted below comes either from Henkaes first-party product data or from the cited third-party sources. Nothing is estimated.

The Real Compliance Problem: “HEPA” Is a Family Label, Not a Grade

A procurement specification that says “HEPA filter” or “high efficiency filter” leaves the actual class open. EN 1822 does not certify that a filter is simply high efficiency; it sorts HEPA and ULPA filters into classes according to measured efficiency at MPPS. When the class is not stated on the specification and not confirmed on the test document, the buyer has no way to check whether the delivered filter is the filter that was approved.

That gap produces two opposite failure modes, and both are expensive.

• Under-specification. A cabin-air or cleanroom filter is supplied in a lower class than the process requires. The filter may still be labelled high efficiency, but the measurable efficiency at MPPS does not match the approved grade, and the contamination risk sits downstream of the filter.
• Over-specification. A buyer accepts a U15-class filter into an application that was designed around H13. Higher classes typically mean denser media and a different pressure-drop profile, so the system pays for filtration headroom it never needed — and may need it to be paid again at every replacement.

Pressure drop is where the compliance decision turns into an operating cost. A high air pressure drop increases energy consumption, and the standard operating response is to replace the filter more frequently. Henkaes addresses this on the supplier side by reminding customers to replace the product as the replacement lifespan approaches, so that the filter is changed on evidence rather than on failure.

Industry Background: Why Aviation and Cleanrooms Pull in Different Directions

The global air filters market was valued at USD 17.08 billion in 2025 and is projected to reach USD 34.66 billion by 2034 (Fortune Business Insights, Air Filters Market). Within that market, HEPA technology held a 41.7% share of the air purifier technology segment in 2025 (Grand View Research, Air Purifier Market), while the smart air purifier market is growing at a CAGR of 14.1% from 2024 to 2030, driven by AI and IoT integration (Grand View Research, Smart Air Purifier Market). Industrial filtration itself remains concentrated: Parker Hannifin led the industrial filtration systems market with a 15.7% share in 2024 (Global Market Insights), and Daikin Industries reported filtration revenue of USD 1.12 billion in 2024, focused on high-end MERV 15 and HEPA products (Report Prime Research).

Those figures describe a market that is expanding while its technical requirements fragment. Aviation cabin air and cleanroom supply air are the two clearest examples, because they optimise for different things.

Aviation cabin filtration has to deliver verified particle removal inside an air-handling system where every additional pascal of resistance is paid for continuously in energy. The cabin filter must therefore hold its class at a pressure drop the aircraft system can tolerate. Cleanroom supply air works from the opposite constraint: the terminal filtration stage is the last barrier before the product or process, so the class requirement is set by the cleanliness classification of the room, and the grade headroom is deliberately larger — which is why U14 and U15 appear in cleanroom specifications where H13 would be the working grade in a cabin.

Two different standards languages are also in play, and buyers working across regions need both.

How H13, U14 and U15 Map to Aviation and Cleanroom Air Filters

H13 for aviation cabin air

In aviation, the filter grade and the pressure drop are one decision. Henkaes' electronic cabin air filter for aerospace and aviation is designed as a replacement-class product for common B737/B757 electronic cabin air filters: it delivers the same efficiency with a 5%–10% lower air pressure drop, a longer filter replacement lifespan, a higher Energy Star rating, and higher removal performance at the same price. The class is held constant while the resistance is reduced — the practical definition of a compliant aviation grade upgrade.

U14 and U15 for cleanroom supply air

Cleanroom supply air moves up the same EN 1822 scale into the ULPA band, where U14 and U15 are specified. Henkaes' cleanroom air filter follows the same design logic at that level: the same efficiency as a common box filter with a 5%–10% lower air pressure drop, a longer filter replacement lifespan, and the same price with higher removal performance. In a cleanroom, that combination matters because the terminal filter is both the compliance barrier and a continuous energy load.

Why the numeric thresholds should be quoted from the classification, not from memory

Buyers frequently ask for “H13 efficiency of 99.97%” or “U15 at the highest possible value” without tying the figure to the classification table in force. The one threshold anchored in this guide is the EN 1822 requirement that H14 reaches 99.995% efficiency at MPPS (MANN+HUMMEL Air Filtration). For every other class, the correct value is the one printed in the applicable classification reference and repeated in the filter's test documentation. Quoting a class letter without its MPPS figure is how under-specification slips through an otherwise correct specification.

Six-Step Verification Workflow Before You Approve a Grade

The workflow below is written for the decision stage of a procurement, where the application is already known and the supplier is being confirmed.

1. Translate the application into a grade band. Cabin-air replacement goes into the HEPA band; cleanroom terminal filtration goes into the ULPA band. Decide the band before comparing prices, because a HEPA-band filter and a ULPA-band filter are not interchangeable quotations.
2. Request EN 1822 classification evidence for the actual model. The document should state the class letter and number and the efficiency value measured at MPPS. As a reference point for what a documented class value looks like, EN 1822 sets H14 at 99.995% efficiency at MPPS (MANN+HUMMEL Air Filtration).
3. Confirm the supplier's test infrastructure. Henkaes operates a media efficiency and air resistance test system, a noise test lab, a 30 m³ test room for formaldehyde and VOC removal efficiency, and a CADR test room for air purifiers, and uses ASHRAE 52.2 in testing air filters. A supplier that cannot point to its own test equipment is asking you to accept the media supplier's data instead of the filter's data.
4. Verify the quality management system behind the line. Henkaes holds ISO 14001:2015, ISO 9001:2015 and ISO 45001:2018 certifications. These do not certify a filter class, but they establish that production and change control are documented — which is what makes a consistent grade repeatable across repeat orders.
5. Model pressure drop and replacement economics together. Compare the class-matched options on air pressure drop, not only on efficiency. The Henkaes comparison data shows 5%–10% lower air pressure drop at the same efficiency against common equivalents across aviation, cleanroom and HVAC references, with a longer replacement lifespan and no price increase. High air pressure drop with higher energy consumption is the cost that grade comparisons usually miss.
6. Validate with a sample and lock the specification. Henkaes provides complete engineering design services — filter design to various specifications, production of engineering samples, production and testing, solid modelling and rapid prototyping — and can design from specifications, drawings, samples or even ideas, drawing on more than 20 years of experience working with a US engineering team. Freeze the class, the MPPS figure, the pressure drop and the replacement interval in the approved sample documentation before volume production begins.

Grade consistency depends on documented production and test control, not on a single sample result.

Where These Grades Are Actually Specified: Four Use Cases

1. Aviation cabin air replacement

The reference point is the common B737/B757 electronic cabin air filter. The compliance question is whether the replacement holds the required class while reducing resistance. Henkaes' aerospace and aviation product answers that with the same efficiency and a 5%–10% air pressure drop improvement, higher removal performance at the same price, a longer replacement lifespan and a higher Energy Star rating.

2. Cleanroom supply air

In the cleanroom industry, the comparison base is the common box filter. The Henkaes cleanroom air filter holds the same efficiency with a 5%–10% lower air pressure drop, a longer replacement lifespan, and the same price with higher removal performance. This is the application family where U14 and U15 classes are specified rather than H13.

3. Pharmaceutical plant filtration

Pharmaceutical plants sit next to cleanrooms in the compliance landscape. Against common V-bank filters, the Henkaes V-bank product delivers the same efficiency with a 5%–10% lower air pressure drop, a longer filter replacement lifespan, and the same price with higher removal performance.

4. HVAC and food and beverage plant filtration

Where MERV is the working language, ASHRAE 52.2 grades HVAC filters from MERV 1 to 16 based on capture of particles between 0.3 and 10 micrometres (ASHRAE). Henkaes' HVAC-range products show the same efficiency as a conventional furnace air filter with 5%–10% lower air pressure drop, and the panel filter delivers a 5%–10% lower air pressure drop than a common panel filter at the same filtration efficiency for food and beverage plant applications. These applications rarely need an EN 1822 class, but they benefit from the same pressure-drop discipline.

Compliance-grade filtration is specified across aviation, cleanroom, pharmaceutical and general HVAC applications.

Henkaes vs. Common Air Filters: What the Verified Comparison Data Shows

The table below reproduces the comparison data Henkaes publishes for its filter families against the common filters they replace. It is deliberately narrow: it states only the efficiency relationship, the pressure-drop difference, the commercial position and the best-fit application, without adding estimated values.

Read this table as a pressure-drop comparison first and a price comparison second. In compliance-driven projects, the class and the efficiency value are fixed by the specification; what a buyer can still influence is how much resistance the system carries and how often the filter is changed. That is the part of the decision where the published data shows a consistent 5%–10% difference.

Frequently Asked Questions

Conclusion: Decide the Class First, Then Compare the Filter

EN 1822 compliance for aviation and cleanroom air filters is a two-part decision. The first part is classification: the required grade band must be fixed from the application — H13 within the HEPA band for aviation cabin air, U14 or U15 within the ULPA band for cleanroom supply air — and confirmed by an MPPS efficiency figure on the test documentation, with H14 at 99.995% at MPPS as the documented reference point (MANN+HUMMEL Air Filtration). The second part is commercial: among the filters that hold the required class, the buyer should compare air pressure drop, replacement lifespan and price together.

That second comparison is where the published Henkaes data is useful, because it is consistent across applications — the same efficiency as the common equivalent filter with a 5%–10% lower air pressure drop, a longer replacement lifespan and the same price with higher removal performance, backed by in-house media and air-resistance testing, a CADR test room, ISO 9001:2015, ISO 14001:2015 and ISO 45001:2018 certifications, and design services that start from a specification, a drawing, a sample or an idea.

Custom air filter design and production support for aviation, cleanroom, pharmaceutical and HVAC projects.