Air purifier? - Part 2

[~WindzStriker~]

Everything is about CADR, clean air delivery rate.

Roughly in theory CADR = air flow x filtration efficiency

Doesn't matter if the filter can remove 100% of the dust if the air flow sux.

Just look at Dyson purifier fan, they keep harping on their best filter but their airflow is poor since there is a huge bypass. That's why they don't publish CADR.

not everything

CADR is good, but if your filter cannot filter all, whats the point ? lol, its like getting a machine to suck air from your room and pump it out of your window (without any filter).

 

[mindgamey]

not everything

CADR is good, but if your filter cannot filter all, whats the point ? lol, its like getting a machine to suck air from your room and pump it out of your window (without any filter).

Please read proper what CADR stands for.

 

[~WindzStriker~]

Please read proper what CADR stands for.

of cause i know what CADR means

 

[Lucky177]

If main concern is just PM2.5, H11 still works well. And I’m just using normal blue filter for below, not green or purple one - for those having doubt. All 3 types works for reducing PM2.5

If got other health concern, other preferences, and filter cost not an issue, then go for other brands with true hepa.

Mi Home app can be buggy at times. So is not without cons.

Xiaomi pro

Edit: And this is what it shows after closing the windows and after continue operate for awhile until now. Running at lower band of favorite fan mode speed.

 

[WussRedXLi]

not everything

CADR is good, but if your filter cannot filter all, whats the point ? lol, its like getting a machine to suck air from your room and pump it out of your window (without any filter).

of cause i know what CADR means

Hi, I know exactly what are you trying to imply, but may I ask where did you read/researched and came to the conclusion that China or any country's H10-H11 cannot filter our haze particles due to its PM size?
Or is your conclusion formed based on your personal understanding of things?



edit - of coz, realistically speaking, CADR is not "everything", the choice must also be based on other things like recurrent cost of filter, unit price, and also one important thing that people miss, the dBSPL sound pressure level at the medium or medium low speeds (and associated CADR at those fan speeds) other than at MAX fan speed.



Actually I have already posted within the past ten pages ago on page 195, and another time to another bro just on Sep 14th Saturday.

So, can all the folks reading the thread currently do yourself a favour, please try read and to understand the past few pages for a moment? Just the past 10-20 pages would do.
This info is actually not new to the thread, actually it has been mentioned for probably > 10 times in this Air Purifier thread (probably much more).




So i say again, these Taobao H10-H11 generic filters and Xiaomi H11 can filter both our haze and even cigarette smoke.





Xiaomi and most/many other chinese branded APs are tested in China scientific labs or test agencies (mostly they use those in Beijing, Shanghai or Guangzhou), they use cigarette smoke as the smoke source.


Test as below to give you a general idea. Note - i have com across another test video documented that is even more pro with cigarette smoke intake is automated and done with interationally recognised lab equipment from TSi, but i can't find that one, coz there are too many of such videos.

So, the particle distribution size for the said cigarette smoke is as follows. (actually just posted again 2-3 pages ago to another bro on 14th Sep 2019 Saturday)

Additionally, this is another diagram, very similar results in the particle distribution size

And some info on our own Singapore haze particle distribution size is as follows, based on actual measurements over here in Singapore.

Note the PM1
https://iopscience.iop.org/article/10.1088/1748-9326/aa75d5/pdf

So it slows that < 1.0 micron forms a very decent percentage of the particle distribution, so how much is that?
Below shows Oct 2015 measured here in Singapore

The diameter growth factor (GF) of 100 nm haze particles at 85 % relative humidity (RH) and their chemical characteristics were simultaneously monitored at Singapore in October 2015 during a pervasive wildfire haze episode that was caused by peatland burning in Indonesia.



For addtional info, below shows the particle size distribution for PM1 for N Thailand forest wildfilre biomass haze. One diagram has its peak centred at 0.45 microns and another 1.5 microns.

So as mentioned above, how are all the Chinese Air Purifiers (and also foreign brands and I have seen Sharp, IQAir, BlueAir even) with their so-called Particulate Matter CADR measured and tested? It is by cigarette smoke in a 30 m3 chamber as standard. Actually, recent attempts have been also made to measure the actual performance in far bigger spaces, eg 100-200 cubic metres ranges if i remember correctly.
These APs are also measured and figures verified by many Air Purifier reviews who sent retail samples to various laboratories and agencies in Beijing / Shanghai / Guangzhou.



How do they do the PM and Formaldehyde CADR tests?
Below youtube vid shows the process

Below done at Guangzhou is just 1 of the many independent tests.

 

[WussRedXLi]

Repost my earlier posting, this is for the generic Taobao HEPA filters that are cheap, those rmb 25 ones.

Of coz, my sensor is just sensitive to around 0.3 to 0.5 microns and not UFP (Ultrafine particles) capable. But this is also based on actual haze measurements here in Singapore.

You can see the detailed particle count numbers as well in the room.

Main thing is must be a workhorse. My Sharp KC-840 11 years old liao. And i'm just using those $4 a piece China HEPA.

All China H11 HEPA (measured to be 92%), except for the Mfresh M8088A which is true H12 HEPA (it's 99% thereabouts).

3 APs in the room. Mfresh M8088A actually is in lowest fan speed, coz i don't wanna load it too much. Most of the cleaning is done by the Samsung AX40 and Sharp KC-840 with China DIY HEPA, cut in size + sides stuffed with bubble wrap for sealing.

GPGT, proof that it works.
Few days ago Singapore haze.

Sudden transient peak @ 40k+ counts @ 0.5 microns

MBR (420 counts @ 0.5)

Mfresh M8088A H12, only 10 counts @ 0.5 microns lowest reading

Sharp KC-840 China DIY H11. Samsung AX40 is similar. 20 counts @ 0.5 microns lowest reading

 

[WussRedXLi]

One more video, this is done by myself. 2015 haze actual measurements.
Particle count numbers included @ 4:00 min mark.


As mentioned, laser sensor is sensitive down to 0.3 to 0.5 microns range.

 

[WussRedXLi]

Of course, the beauty of capitalism is such that if you can afford it, then go ahead and get the IQAir. Great stuff if you can afford.

 

[WussRedXLi]

One more thing, if you are an overseas reader and hail from cities where there is photochemical smog sometimes eg Klang Valley, on the Malaysia DOE APIMS you'd see the API value having ** double asterix, meaning that it is due to ozone conversion, then yes there might be a high % count of UFP - Ultrafine particulates.

But even then, a Xiaomi MAX has a smoke CADR of 1000 m3/hr (go check some verified measurements, it's around 9xx m3/hr), with cigarette smoke as source, digging down to slightly under 0.1 microns. Things do not fall like a cliff once it hits 0.1 microns and below. (see the graph above as cigarette smoke source)
Even 20% of this 1000 m3/hr figure is 200 m3/hr CADR @ 0.1 microns, for eg.

A Dyson bladeless air purifier has a CADR of 137 m3/hr and filters 0.1 microns to a very high degree that is close to 100%. The Amway Atmosphere AP iirc also advertises a 0.1 micron % filtration rate. But the price difference is staggering.
IQAir filters is another one that guarantees its 0.1 microns performance.



You see which one you wanna choose.


If you are interested in UFP due to photochemical smog, you can also choose from Taobao the cleanroom FFUs (Fan Filter Units) and choose a ULPA U15 to U17 filter.
Choose sea shipping. Shouldn't run you over 400 bucks shipped.
Crazy ass m3/hr air shifting + low dB SPL performance.

 

[kurtgoh]

thinking of getting an air purifier..

but some thoughts i had.

Xiaomi pro in living room + ION PUREAIR in master.
or
just xiaomi pro, since haze only come a few days in a year..

when you all using the purifier, do you keep the windows open or closed?

 

[Shib]

Repost my earlier posting, this is for the generic Taobao HEPA filters that are cheap, those rmb 25 ones.

Of coz, my sensor is just sensitive to around 0.3 to 0.5 microns and not UFP (Ultrafine particles) capable. But this is also based on actual haze measurements here in Singapore.

You can see the detailed particle count numbers as well in the room.





All China H11 HEPA (measured to be 92%), except for the Mfresh M8088A which is true H12 HEPA (it's 99% thereabouts).

3 APs in the room. Mfresh M8088A actually is in lowest fan speed, coz i don't wanna load it too much. Most of the cleaning is done by the Samsung AX40 and Sharp KC-840 with China DIY HEPA, cut in size + sides stuffed with bubble wrap for sealing.

GPGT, proof that it works.
Few days ago Singapore haze.

Sudden transient peak @ 40k+ counts @ 0.5 microns

MBR (420 counts @ 0.5)

Mfresh M8088A H12, only 10 counts @ 0.5 microns lowest reading

Sharp KC-840 China DIY H11. Samsung AX40 is similar. 20 counts @ 0.5 microns lowest reading

Wow. How many detectors do you have? &#55357;

Sent from HUAWEI EVR-L29 using GAGT

 

[dnsfpl]

is it just me or it's true that our nose can feel the difference when we breathe purified air?

 

[yamakazi51]

is it just me or it's true that our nose can feel the difference when we breathe purified air?

Different people different sensitivity level. Some can smell the haze especially if ‘wet’ or after a rain. Personally will have dry, sore throat, sneezing and phlegm. So the threshold when you’ll have these symptoms will be different from person to person.

 

[meesoto]

There are some chinese APs with very high CADRs, 600, 700++ m3/hr. I posted them before on pages not more than 50 pages before this, during the Malaysian Pasir Gudang haze. Take a look there.

eg

Thanks for the links again. Yeah. I looked at the larger Chinese units. Guess I am also wanting some local feedback from others who have bought these larger non-Xiaomi APs. Seems like either everyone is using older units from the past few years or getting Xiaomi 2s/Pros.

 

[mindgamey]

Thanks for the links again. Yeah. I looked at the larger Chinese units. Guess I am also wanting some local feedback from others who have bought these larger non-Xiaomi APs. Seems like either everyone is using older units from the past few years or getting Xiaomi 2s/Pros.

The gurus here have already stockpiled masks, air filters and purifiers.

I never believe the new president can stop the haze since it's a combination of nature and man made causes.

 

[WussRedXLi]

Thanks for the links again. Yeah. I looked at the larger Chinese units. Guess I am also wanting some local feedback from others who have bought these larger non-Xiaomi APs. Seems like either everyone is using older units from the past few years or getting Xiaomi 2s/Pros.

Yeah......if every year is like 2015, 2019, or even 2010 or brief very high-level spikes like 2013 (PSI 401 and that's based on 3hr PSI PM10, so the "index figure" for 1hr PM2.5 would even be significantly higher), i think i'd be willing to invest in a big ass one.

Anyway, my Mfresh M8088A is already 570 m3/hr CADR anyway. It was just rmb 988 then, and that time 4PX sent it over at 8kg weight, so that's 6 + (4 x 7) = SGD 34. It is something like a slightly fatter version of the Xiaomi Pro.
These electronics/small motor stuff still can be sent via official forwarder that time.

So if there is a need to put it into Turbo and blast, i still have something to do the shifting of air. Too loud though for anything more than 15 mins as it is 62dBA SPL.

After reducing the levels, i can switch to fan speed 2 or something, and together with the Sharp/Samsungs i can just maintain and coast along.


Also, my house is just 95 sqm. For those in penthouses or landed, with the living room area already at say 180 sqm and bedroom at 60 sqm, it might be a different story.

Wow. How many detectors do you have? *********

Sent from HUAWEI EVR-L29 using GAGT

Too many, that's why i sold one to bro MIVEC325 after 2015.

 

[MIVEC525]

Yeah......if every year is like 2015, 2019, or even 2010 or brief very high-level spikes like 2013 (PSI 401 and that's based on 3hr PSI PM10, so the "index figure" for 1hr PM2.5 would even be significantly higher), i think i'd be willing to invest in a big ass one.

Anyway, my Mfresh M8088A is already 570 m3/hr CADR anyway. It was just rmb 988 then, and that time 4PX sent it over at 8kg weight, so that's 6 + (4 x 7) = SGD 34. It is something like a slightly fatter version of the Xiaomi Pro.
These electronics/small motor stuff still can be sent via official forwarder that time.

So if there is a need to put it into Turbo and blast, i still have something to do the shifting of air. Too loud though for anything more than 15 mins as it is 62dBA SPL.

After reducing the levels, i can switch to fan speed 2 or something, and together with the Sharp/Samsungs i can just maintain and coast along.


Also, my house is just 95 sqm. For those in penthouses or landed, with the living room area already at say 180 sqm and bedroom at 60 sqm, it might be a different story.



Too many, that's why i sold one to bro MIVEC325 after 2015.

Wa...still rem me...its still in my car...

 

[WussRedXLi]

Here's a video of the SPL of the Xiaomi version 2 vs the Mfresh M8088A.

 

[WussRedXLi]

Wa...still rem me...its still in my car...

You still in this thread!

Is it still working?

My Samo Air temperature and RH% sensor went bonkers already. Luckily the laser module still working.

 

[Halo green]

sorry to ask a noob question. does any1 know how to see these readings? what's the psi?