True HEPA vs HEPA vs H13 vs H14 (and ULPA): What the Labels Mean

"True HEPA" and "HEPA" should mean the same thing: a filter that captures at least 99.97% of particles at 0.3 micron, the U.S. Department of Energy benchmark. The trouble is labels like "HEPA-type," "HEPA-like" and "99% HEPA." These aren't held to that standard, which is why manufacturers started saying "True HEPA." H13 and H14 come from the European EN 1822 standard, which grades filters at their weakest point (the most penetrating particle size). H14 lets through about ten times fewer particles than H13. ULPA filters go further still and are mostly used in cleanrooms.

HEPA Filter Grades at a Glance

The most penetrating particle size is the size a filter is worst at catching, typically somewhere around 0.1 to 0.3 micron. Particles bigger and smaller than that are caught more easily. That's why a HEPA rating "at 0.3 micron" is a conservative number, not a cutoff.

True HEPA vs HEPA

A filter that really meets the HEPA standard can be called either one. "True HEPA" is the industry's way of separating real HEPA from "HEPA-type" filters. When you shop, look for the actual efficiency number (99.97% at 0.3 micron), not just the word HEPA. The EPA notes that consumer air cleaners have no single, widely accepted HEPA definition, so a stated efficiency matters more than the label.

Airpura's standard R, UV, V, F, G and P models (600 and 700 series, not DLX) use a True HEPA filter rated 99.97% at 0.3 micron. For example, the Airpura R600 pairs it with an 18 lb carbon bed.

H13 vs H14

Both are true HEPA grades. The difference is how many particles get through at the most penetrating size: an H13 filter can pass up to 0.05%, while an H14 passes no more than 0.005%. In practice, H14 is chosen for people who want the most particle capture possible, such as those with severe allergies, asthma or immune concerns, or anyone filtering fine smoke.

Airpura's 614 and 714 models use a Super HEPA H14 filter that Airpura rates at 99.99% at 0.3 micron. Options include the R614 for everyday use, the UV614 for germs and mold, and the V614 for VOCs and wildfire smoke. For a larger room, there's the R714.

HEPA vs ULPA

ULPA (ultra-low penetration air) filters are denser than HEPA, which makes them harder for air to pass through. A fan pushing air through ULPA media moves less air or works harder. That's why ULPA is common in semiconductor and lab cleanrooms but rare in home purifiers. For a home, a high-airflow purifier with True HEPA or H14 usually cleans a room faster than a low-airflow unit with a denser filter.

What Is a HEPA Barrier Filter?

Airpura's C and T series, and the F and G DLX models, use a HEPA Barrier filter instead of True HEPA. Airpura rates it 95% at 1 micron, so it catches fewer fine particles than True HEPA. These models carry a 26 lb carbon bed instead of 18 lb, because they're built for chemical and tobacco smoke problems where gases are the main target. If fine particles matter most to you, choose a True HEPA or H14 model. If chemicals and odors matter most, see the C600 or T600.

The Filter Isn't the Whole Story

• Airflow: A great filter in a weak fan cleans a room slowly. Check CFM and the rated room size. Airpura's 600 series moves 560 CFM and the 700 series 635 CFM.
• Seal: Air that leaks around the filter isn't filtered. Look for a solid housing and a well-seated filter.
• Gases: HEPA catches particles only. For odors, smoke gases and VOCs, you need carbon too. See HEPA vs carbon filter.

True HEPA vs HEPA FAQs

Is True HEPA better than HEPA?

If both meet 99.97% at 0.3 micron, they're the same. "True HEPA" is used to set real HEPA apart from "HEPA-type" filters, which aren't held to a standard.

Is H13 or H14 better?

H14 is stricter. It allows no more than 0.005% of particles through at the most penetrating size, versus 0.05% for H13.

Is H13 true HEPA?

Yes. H13 and H14 are both HEPA classes under EN 1822 and ISO 29463.

Is ULPA better than HEPA for a home?

Not usually. ULPA filters catch more, but they restrict airflow, so a home purifier using one can move less air. High-airflow HEPA or H14 is the practical choice for most homes.

How long do HEPA filters last?

In Airpura units, True HEPA and Super HEPA filters last 3 to 5 years under normal use. The carbon is replaced about every 24 months.

Related Comparisons

• MERV vs HEPA
• Ionizer vs HEPA air purifier
• Airpura vs Austin Air vs IQAir

Shop air purifiers for asthma and allergies or all Airpura air purifiers.

Sources: U.S. EPA, Residential Air Cleaners: A Technical Summary (3rd ed.); EN 1822 / ISO 29463 filter classes; Airpura product specifications.