Quid est HEPA? Terminus generalis saepe male usurpatus

In mercatu, filtri plicati communiter sub nomine HEPA coniunguntur. Hoc simpliciter est terminus generalis, quem homines pro commoditate adhibuerunt, cum de hac classe productorum loquuntur — stricto sensu, non est accuratus.

Quid vere HEPA est

HEPA significat High Efficiency Particulate Air.

Hoc generaliter ad media filtrantia refertur, quae extremam efficaciam filtrationis in specifica magnitudine particulae habent, saepe exigens efficaciam 99,95% aut 99,97% et supra. Tamen definitio specifica et conditiones experimentales ab uno normativo ad aliud variant.

Quomodo diversae normae id definunt

IEST-RP-CC001.7 (norma Americana)

· Typus A: cum PAO ut aerosolo provocante examinatur, exigens efficaciam filtrationis 99,97% et supra in particulis 0,3 micron et maioribus.

· Typus H: aerosolum provocans esse potest PAO, DOP, aut alia media, exigens efficaciam filtrationis 99,97% et supra in particulis 0,1–0,2 aut 0,2–0,3 micron.

EN 1822 (norma Europaea)

The challenge aerosol for EN 1822 testing may be DEHS, PAO, PSL, and is not limited to these substances. It requires testing the filtration efficiency at MPPS (the Most Penetrating Particle Size) at ≥99.95%, and the test may be run with or without discharging the electrostatic charge.

Why the EN 1822 Does Not Apply to Air Purifier Filters

Filter pads used in air purifiers are typically made from electret meltblown filter paper. Once the electrostatic charge is discharged, this class of media has an extremely low filtration efficiency, and its MPPS efficiency falls below the paper's nominal grade. EN 1822 therefore does not apply to HEPA filters used in air purifiers, and its grades cannot be used to endorse this type of filter.

Diagram comparing particle capture in electret filter media with the electrostatic charge present versus discharged

De nobis

Dongguan Walson Environmental Purifying Technology Co., Ltd. (Walson) is an air purifier filter factory located in Dongguan, Guangdong.

Diagramma de capacitate et magnitudo probationis in fabrica: laboratorium venti, camera probationis 81 m³, laboratorium analysium chemicarum, plus magnitudo fabricae, numerus operariorum, capacitas mensualis et certificata

Nostri clientes hodie sunt praecipue domini et fabricantes purgatorum aeris, necnon mercatores posteriores et post venditionem.