空氣清新機 邊隻好

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Tkt 2024-04-15 19:12:00

Philips Coway made in korea 都好啲. 宜家個啲唔得.

球神美斯 2024-04-15 19:16:24

會唔會係佢出題示要你清潔，先至可以reset

WAI? 2024-04-15 19:35:11

而家有時間寫多D

上面位巴打係咁問我知唔知HEPA係咩，我唔知佢想反駁我D咩，不過佢對MPPS呢樣野完全冇反駁過，不如佢直接講出佢嘅理解

Q1. 咩係HEPA 濾網？

https://en.wikipedia.org/wiki/HEPA
HEPA (/ˈhɛpə/, high-efficiency particulate air) filter,[1] also known as high-efficiency particulate absorbing filter[citation needed] and high-efficiency particulate arrestance filter,[2] is an efficiency standard of air filters.[3]
Filters meeting the HEPA standard must satisfy certain levels of efficiency. Common standards require that a HEPA air filter must remove—from the air that passes through—at least 99.95% (ISO, European Standard)[4][5] or 99.97% (ASME, U.S. DOE)[6][7] of particles whose diameter is equal to 0.3 μm, with the filtration efficiency increasing for particle diameters both less than and greater than 0.3 μm.

https://www.philips-da.com.tw/blogs/product-tips/136499
HEPA濾網全名為High-Efficiency Particulate Air ，即高效率空氣微粒過濾，是一種標準，而不是濾網種類。HEPA標準由美國能源部訂定，不論材質，能有效過濾大於等於0.3微米（µm）的空氣微粒，過濾效果達到99.7%以上，才能稱為「HEPA濾網」

https://tw.sharp/faq/view/348
HEPA為一種標準而不是名稱，依據美國能源部的定義：能夠把超過 99.7%，大小為0.3微米（μm）的懸浮微粒擋下來的濾網，不論濾網是紙、不織布或玻璃纖維製成的，只要過濾效率符合這個數值，都可以稱作 HEPA濾網

我完全唔明HEPA有咩難理解，不如請佢直接解釋

Q2. 點解HEPA係睇0.3微米？

https://www.epa.gov/indoor-air-quality-iaq/what-hepa-filter
The diameter specification of 0.3 microns corresponds to the worst case; the most penetrating particle size (MPPS). Particles that are larger or smaller are trapped with even higher efficiency. Using the worst case particle size results in the worst case efficiency rating (i.e. 99.97% or better for all particle sizes).

https://www.sanalifewellness.com/blog/true-hepa-vs-hepa-filter-whats-the-difference
A HEPA-type filter is genuinely an inferior version of the True HEPA. Unfortunately, due to trademarking, a HEPA-type filter can be sold under pretenses to trick consumers into believing that the HEPA-type is close to or as effective as the True HEPA.
A HEPA-type filter only has an efficiency rating of 99%, and they are effective at capturing 0.2 microns sized particles. While this may look more impressive (compared to the 0.3 effectiveness of the True HEPA), it is not.
The 0.3-micron particle is the MPPS (most challenging particle to capture), and through the technology of the True HEPA, the 0.3 micron-sized particles bounce into particles of 0.1 microns in size. They can capture these smaller particles (usually viruses and bacteria such as the common flu virus).

因為0.3係MPPS，最難濾嘅大細，係代表worst case

WAI? 2024-04-15 19:36:11

Q3. HEPA濾唔濾到0.3微米以下？

https://en.wikipedia.org/wiki/HEPA
with the filtration efficiency increasing for particle diameters both less than and greater than 0.3 μm.

https://www.sanalifewellness.com/blog/what-is-the-most-penetrating-particle-size-mpps
An MPPS of 0.3 microns is the worst case; ironically, many filters are more effective at capturing particles smaller or larger than this, but a 0.3 micron particles regularly gets by basic filtration. Using 0.3 microns as the MPPS measures the worst-case efficacy of the filter.

https://www.epa.gov/indoor-air-quality-iaq/what-hepa-filter
The diameter specification of 0.3 microns corresponds to the worst case; the most penetrating particle size (MPPS). Particles that are larger or smaller are trapped with even higher efficiency.

https://smartairfilters.com/en/blog/can-hepa-filters-capture-nanoparticles/
Researchers at the University of Minnesota tested this question with weaker fiberglass furnace filters and higher-grade HEPA filters. In their test, they shot particles of silver from 3 to 20 nanometers at the filters.
The results showed that filters captured 99.99% of particles smaller than 5 nanometers.
Their results demonstrate that the miracle of Brownian motion isn’t just a HEPA thing. This principle works for any fiber filter, including furnace filters (also called “MERV filters”). In the graph above, the MERV filters captured about 99% of particles at 10 nanometers and 99.9% at 4 nanometers. That’s impressive for a cheap fiber filter.