At the Trenntech filtration laboratory in Frankfurt, Germany, engineers face various misunderstandings from customers and the market every day.Here are the top ten common misconceptions they have summarized, along with the scientific truths:
Misconception 1: HEPA is the highest filtration standard
Many people believe that HEPA represents the pinnacle of filtration technology. In reality, in the ISO 29463 standard system, HEPA is only an intermediate level of high-efficiency filtration. The true top of the pyramid is ULPA, with filtration efficiency starting at 99.995% and reaching up to 99.9999995%. Below HEPA is the EPA level, covering an efficiency range of 85%-99.5%.
Misconception 2: Higher numbers mean better performance
The belief that H13 is always superior to H12 is a common misconception. In fact, higher-level filters mean a denser fiber structure, which leads to problems such as a 30%-50% increase in initial resistance, increased energy consumption, and potentially reduced dust holding capacity. In laboratory tests, Trenntech found that over-specifying H14 filters for ordinary environments actually leads to energy waste and increased noise. The scientific approach is to precisely match the filter to the specific needs.
Misconception 3:ULPA is not suitable for home use
ULPA is often considered too high-end for ordinary households. This misconception ignores the special needs for protection against ultrafine particles in modern life. Research from the Mainz Medical Center shows that viral aerosols and ultrafine particles produced by combustion are mostly below 0.1 micrometers, which is precisely the advantage range of ULPA. Home ULPA systems developed for vulnerable populations have proven to reduce the risk of respiratory infections by more than 40%.
Misconception 4: EPA is just a basic filter
Simply understanding EPA filters as “basic filtration” is a serious underestimation of their function. In a complete three-stage filtration system, EPA undertakes the task of capturing 85%-99.5% of particulate matter, acting as a crucial barrier to protect the subsequent HEPA/ULPA filters. Corresponding comparative experiments show that systems lacking effective EPA protection will see the lifespan of subsequent HEPA filters shortened by more than 60%.
Misconception 5: HEPA filters can completely filter out viruses
While HEPA filters are over 99.99% efficient at filtering out virus-laden droplets (1-5 micrometers), individual virus particles (0.02-0.3 micrometers) can indeed penetrate some HEPA filters. In real-world hospital tests, wards equipped with H14 filtration systems had a 73% lower rate of airborne infections than regular wards, but this requires a comprehensive air management strategy.
Misconception 6: Washable HEPA filters are economical
Washable HEPA filters advertised on the market often experience a 15%-30% decrease in efficiency after the first wash, and after three washes, most have dropped to EPA levels. From an economic perspective, considering performance degradation and replacement frequency, the annual cost of traditional disposable H13 filters is actually more than 20% lower than the so-called “washable” options.
Misconception 7: Replacement only depends on usage time
Replacing filters solely based on time is a huge waste or risk. According to actual intelligent monitoring systems, the filter load in different environments can vary by up to 300% within the same usage time. The scientific approach is to replace filters based on differential pressure sensor data; when the resistance increases to twice the initial value, replacement is necessary. This ensures both efficiency and optimizes service life.
Misconception 8: All HEPA standards are the same
The claim of “meeting HEPA standards” masks significant differences in standards. The US HEPA standard (99.97%@0.3μm) and the European H13 standard (99.95%@MPPS) have completely different testing methods and requirements. Trenntech conducted simultaneous testing of multiple standards in its laboratory and found that the same product may have a two-grade difference in rating under different standards.
Misconception 9: Price determines filtration performance
High price doesn’t always mean high performance. Market research shows that the actual efficiency of some high-end brand filters is comparable to mid-range products, with the price difference mainly coming from brand premium and added features. Trenntech advises consumers to focus on independent third-party test reports, rather than relying solely on price.
Misconception 10: Installation is a one-time solution
Even the best HEPA/ULPA filters, if improperly installed, can lead to edge leakage, reducing overall efficiency by more than 90%. Engineers recommend using professional installation methods: scanning around the filter with a particle counter to ensure that the leakage rate at all seams is below 0.01%.
From precise laboratory measurements to complex real-world applications, Trenntech’s expert team is dedicated to dispelling uncertainty with scientific data. In this age of information overload, understanding the truth about efficient filtration technology is not only about technical choices but also about everyone’s respiratory health. True professionalism lies not in blindly pursuing the highest specifications, but in precise matching based on scientific understanding—this is the essence of German precision engineering.