UPDATE, 2024: Please check out my buyer’s guide to air purifiers; my 2014 review of the science behind air purifiers; my 2015 tests of air purifiers under 1,000 RMB plus my 2014 review of two dozen top air purifier models in China. This post has affiliate links.
Beijing’s internet forums are always filled with heated debates as to which air purifier is best: IQAir vs Blueair vs others; import vs local; etc etc. I finally decided to jump into the fray and enter the great debate. As I’ve mentioned in many posts, I am a big fan of indoor air purifiers because I think indoor air pollution is a serious public health concern here in China. And while indoor plants can help a lot, I think the machines are far more effective. So, which machine should you buy — if any?
I personally use three brands; in my small office I have a Hunter 31125, which is a true-HEPA filter. It’s Taiwan-made from the American company Hunter, and I bought it for around 1248RMB at the Sundan electronics store at the Sanlitun Village mall basement. At home, we have two machines which are also HEPA filters; the bedroom has the Blueair 501 which we bought for around 6,000RMB. The current model would be the Classic 480i. Our living room has an IQAir HealthPro 250, also called the IQAir HealthPro Plus, which I believe was around 11,000RMB.
Real World Tests: Blueair 501 vs IQAir 250
Last year I borrowed an air particle monitor from IQAir and did a lot of spot checks at home to check out which purifier at home — my IQAir or Blueair — worked best. My den (living room) is about 40+ square meters, and my bedroom is ~20 square meters. Both of my machines’ filters were a couple months old. The original data is in the table below (note that “%” means “percent of that room air versus current outdoor air”).
You can parse (spin?) the data many ways, but here are my conclusions:
- Normal settings: with the typical mid-level speeds, I didn’t see much of a difference. Both took out 60-80% of the particulates.
- Max settings: Again, I found no major difference. Both removed 80-90% of particulates.
- On the worst days with AQI over 500 (!), I still couldn’t get any room under the more desirable 100,000. Scary, no?
- Rooms are different: my bedroom consistently had better air than the den (good news for me)
- Without any air purifiers, the indoor air was 72% of outdoor air
My Hunter Did Very Well
My smaller air purifier, the Hunter 31125 in my small office, also did quite well. It routinely got 50-70% of pollution even with the constant door opening. At max speed with the door closed for a while, it got 91% of the pollution. I think this is a great option for small rooms, and at 1290RMB is far cheaper and smaller than the other brands.
Real World Reviews: Survey Says…
Readers should definitely read the most objective sources out there and try to avoid the many “review” sites which are essentially shills for selling particular brands. One reputable consumer group, which is free, is the Consumer Search group. In their reviews of air purifiers, they list:
- Best Air Purifier Overall: IQAir HealthPro Plus
- Best Value: Austin Air HealthMate
- Best For Small Rooms: Honeywell Enviracaire
This website has a ton of good info and links to the most reputable reviews, so readers should definitely use this website. The magazine Consumer Reports also has an excellent reputation for reviews; interested people would need to pay online to download their review of air purifiers, but a tiny one-month charge is nothing compared to the thousands you may spend on machines, and their advice is highly regarded.
What About Local Products?
I would love to endorse a locally made brand such as one from China’s reputable brand Yadu, but I’m simply not aware of any good research, at least available in English. If anyone has such information, please share with readers in the comments section below.
The Bottom Line: It’s All A Cost-Benefit Analysis
So here you are with all this information, and you need to decide. The biggest factors are quality and cost. Buying imported seems to be a no-brainer, at least for now. In my real-world tests, I didn’t see much difference at all between Blueair and IQAir. IQAir does have many good reviews out there but the price difference is a serious issue for many; it’s less of an issue if you plan to resell, since the resale value is high. I think the next level under these two brands are the highly regarded but less locally available models from AlenAir, Austin Air, and Honeywell. I’ve read on the Beijing blogs that some are happy with Alen Air, which has an easy website in English and ships for free from Hong Kong. (I think World Health Store just started to carry Alen Air?)
Where To Buy
You can use these links to access the IQAir and Blueair Amazon storefronts. Here are direct links to Blueair 501 (currently the Classic 480i) and the IQAir HealthPro Plus (250).
Don’t Get Ozone Ionizers
Last but not least; do not buy ozone-creating purifiers that ionize the air. This was trendy a few years ago, but there is now excellent data that ozone itself is an indoor hazard. No reputable company or reviewing magazine recommends ozone-creating ionizer machines anymore.
Air Pollution Info-junkies, Here’s Your Fix
I created a full page listing my top pollution articles here.
UPDATE 2024: Please follow me at my new website, DrSaintCyr.com. Also my new YouTube channel youtube.com/@drsaintcyr
we're running a few yadu purifiers in our home, and for those of laowai who are on limited budgets these are by far the most cost effective option (i think we paid around ~RMB700 for each purifier). they seem to work well, but I would also love to see documented results of how the yadus stack up against IQ and Blueair. Even 2 or 3 yadus would be much much cheaper than 1 IQAir…
Does your purifier say “HEPA” on the packages? I would also love to see some real comparisons between Yadu and other brands. Does anyone have this info, or something printed in Chinese?
Can you tell me – is it okay to work out indoors at a gym on a day when the air quality outside is considered hazardous?
Should going outside be avoided on "hazardous" days?
Also the US embassy publishes daily readings of Beijing's air quality- I am sure you are aware.
I checked out some air filters in store and noticed that many had poor fitting filters and in one case the back side where the clean air should be was covered in dust. The seal around the filter is critical to correct operation and it seemed to me on inspection that many of the local brand models I checked had design flaws or manufacturing flaws allowing some (all?) air to bypass the filter. However, I'm pretty sure with some draft excluder tape or duct tape they could work correctly assuming the filter itself is sound.
I recommend disassembling and checking the seals thoroughly.
I am planning to live in Beijing for 6 months in 2011 – but I'm really concerned about the air quality, because I had serious bronchitis problems last time I stayed there for 2 months (not to mention loosing a lot of hair, but I have no idea what caused that). Is there any way to assess the quality of the HVAC system and indoor air quality before signing a lease? Or are certain buildings known to have better air than others??
Also, are there air quality measurement devices that are affordable enough for individuals when making decisions about apartments, gyms, schools?
I know that both IQAir and Blueair reps (from Torana) can do home visits and check pollution, but I’m not aware of how to do this before moving in. And I’m not sure if their machines check for VOCs or other compounds besides particulate matter…as for which places are safer, that’s tough. Both new and old places can have problems with paint and VOCs off furniture. I think in general it’s easier just to buy a top air purifier that takes care of all the bad stuff, both indoor and out.
We’ve been using two Yadu for a couple years now. We have the biggest units, two of them, for an apartment that’s about 100sqm. We simply cannot afford the cost of the IQAir. There is a HEPA filter, an activated carbon filter and simple large dust filter. As Roger Underhill notes, the Yadu, like many locally made products, have a serious problem with the seals fitting. When you look at it closely, you see that all the air will just be drawn up and around the HEPA and carbon filter instead of through them. However, this was a very easy fix. Whenever I install a new set of filters, I use weatherproofing strips all around them to seal them tightly. At times it’s so tight I can hardly get the cover back on. But this does ensure that air is going through the filters. Once when I had no weatherproofing tape, I used silver insulating tape (available for about 3 RMB a roll at any little shop that sells hardware and home repair stuff–this is the stuff used on planes and will be a fine seal if done correctly). It’s a simple matter to slit that tape and put down a new strip when you get new filters.
We have not measured anything, so can’t tell you what the Yadu filters do. But I can tell you that whenever I’m outside, even on “blue sky days,” I can’t breathe deeply to the bottom of my lungs without a slight hitch or ache. Since getting the Yadu filters I’ve never had that problem indoors. I also have very occasional asthma that used to flare up any time I got a cold. No problem with that since getting the filters. My flatmate had problems with the “eternal winter cold” that would set in around Oct or Nov and not leave till March or April. No problem since getting the filters (as well as no more biking to work in the winter). Finally, when I used to walk outside for exercise, (which I almost never do now), I would always feel a little lightheaded and tired. Now I use an elliptical in our apartment’s air, only, and exercising actually feels good and energizing.
Thanks for the reply! I’m glad you’re happy with your Yadu — can you share how much it cost? I’m definitely worried about those “air leaks” you describe, even with the tape it just shouldn’t do that in the first place.
I’ve also got a Yadu, the KJF2801N (I’m guessing it’s the same one that Miriam has, it used to be the top-of-the-line model until a couple of years ago when they came out with a new massive and rather hideous-looking model). It retails for around 4500RMB but you can get it cheaper online (Taobao). This may seem expensive for a local brand, but the Yadu has much lower running costs than the ones listed here – a set of replacement filters (pre-filter, carbon, and HEPA) currently runs less than 170 RMB (last year I only paid 110 RMB for a set of replacement filters, but it seems with the recent hype about PM2.5 these filters are in short supply). Trust me, with the pollution levels in Beijing you’re looking at replacing filters every 4 months if you keep your purifier running 24/7. So these filter costs definitely do add up. It’s also how these air purifier makers make the meat of their profits (think razor blades).
The 2801N has a lot of bells and whistles, including indicators on the LCD screen for different types of pollution and a simple remote. It also has a humidifiying function; as you know it gets really dry during the winters in Beijing, especially with the public heating cranked up so high. This is the first winter that we’ve left ours running 24/7 and the humidifying function works surprisingly well – with it on our indoor humidity level is always above 40%.
As for effectiveness, the sealing on the filters could be better, but like Miriam mentioned this is a simple DIY fix. Though I did notice that my last set of filters were much improved in this regard, so I didn’t bother. I can’t give you actual numbers, but I will say that the filters get filthy after just a couple of months use, so it definitely is helping with the air quality. By the way, I keep the fan on the medium setting (there are 3 speed settings, plus auto).
I’m actually thinking of getting a second unit, to put at the other end of our living room. Our living room isn’t huge by any means, but I think there’ll be better circulation/cleaning that way. I was thinking of getting a Blueair or AlenAir, but the replacement filter costs for these are quite high. I’ll probably just get another Yadu.
One last thing – Yadu’s after-sales support is excellent. When we first got our Yadu we couldn’t figure out how a certain function worked, so we called Yadu customer service. They ended up sending a technician over the same evening, even though it was probably past his regular working hours (it was after 6:00pm when we called and he showed up around 8:00pm). The tech was very nice and patiently showed us how to use the function in question. He also had brought up a brand new unit in case ours was defective. When he left he gave me his mobile number and told me to call him if we had any more questions.
I agree that Yadu’s customer service is good; when our humidifiers konk out, they can drop by quickly and fix for 40RMB (plus parts). But I’m still waiting to see any data on Yadu’s effectiveness in air pollution. Does anyone have that data? Hasn’t any geek with a particle monitor checked out these machines? Yadu, if you’re listening, I’m more than willing to test your flagship models, send me an email…
I probably qualify as a geek but I cannot afford a particle monitor (unless affordable ones exist). Hopefully Yadu will take you up on your offer.
I’m actually of the opinion that as long as the purifier uses a “real” HEPA filter, it’s much better than nothing.
Hi,
I am considering purchasing a Blueair 203 for a small bedroom but I am a bit concerned about the technology they use. And even though they describe their product as almost ozone free, I could not find any independent testing/study to confirm what Blueair website affirms.
Also, does the purifiers stays ozone free over the years?
I see that you use one of their purifiers, have you been able to test the ozone levels by yourself or found any relevant article/benchmark to confirm what the manufacturer says?
thanks for the good articles and advices
Sorry, my machine doesn’t check for ozone. In my personal opinion, ozone is not at all needed to clean the air and I see a lot more scientific concerns than praise for machines that create ozone. HEPA is the key. I always find it counterintuitive that a machine would add a chemical that is one of the specific air pollutants we are supposed to be avoiding!
Yes, but the point is, blue air uses an ionizer, which creates ozone, unavoidably, as a side-effect.
Blue Air filters seem a bit controversial, in the sense that, generally we assume that the Most Penetrating Particle Size (“MPPS”) for a filter is 0.3 microns. And the tests are run therefore for this size of particles (using salt particles mostly), and you can test this with an optical counter.
However, electrostatic filters (and Blue Air is using electrostatic forces to enhance their filtration, using an ionizer) have an MPPS significnatly smaller, around 0.05microns, eg see http://annhyg.oxfordjournals.org/content/53/2/117.full Therefore, any measurements we make of Blue Air effectiveness, which tend to be for test particles of 0.3 microns, might be flawed.
In addition, Blue Air doesnt have a pre-filter (to increase CADR in tests…), and plausibly gives worse filtration when dirty (cf a mechanical HEPA-filter will actually filter better when dirty, but with a lower flow rate, as it gets clogged).
Currently, I”m plucking up the courage to save up for an IQAir 🙁
No, Blueair officially doesn’t increase any ozone in the room, that’s been confirmed and discussed on Consumersearch and their own websites. So it’s safe that way. And you can bring up all these theoretical issues but the fact remains in my own testing, in Consumer Reports, in Smartairfilters.com, etc — Blueair always does a great job eliminating PM0.3, PM0.5, PM2.5, PM10. I’ve tested all those levels using different machines.
Thank you for your blog. It’s very helpful for us. I’ve read your articles for several times to see which air purifier to buy.
I was almost to buy Blueair, but since I found an article below, I’m not sure if I should get Blueair, since the article says Blueair emits ozon. What do you think about this?
http://www.consumersearch.com/air-purifiers/air-purifiers-and-ozone
The same article says all Blueairs meet standards for ozone, and I’ve seen plenty of other articles, including directly on Blueair website, which directly show graphs showing no ozone created in the room. I wish I could find that article, I’m still looking but no, I’m not worried, it’s not an ozone making machine. Torana also mentions this http://www.toranacleanair.com/BlueairCleaners.html ; you’re welcome to email them for the data.
Thank you very much for your response. I will contact torana for the data.
Yet I’m still confused by reading articles below. I’m not fully convinced to buy Blueair.
1. http://www.blueair.com/India/en/support/cleanairlibrary/ozoneandairpurification.html
According to this, Blueair emits ozone 0.003ppm. (Then they say it’s far below the most stringent U.S. safety standards.) What I understand from this fact is; Blueair does emit very small amount of ozone, but as long as it’s below safety standards, it won’t be harmful.
2. http://www.arb.ca.gov/research/indoor/aircleaners/certified.htm
They say “Blueair’s ionizer does produce ozone, so if you have breathing-related issues, you’ll want to avoid this air purifier.”.
3. http://www.consumersearch.com/air-purifiers/air-purifiers-and-ozone
Last sentence of this article, “We now believe that air purifiers that emit even small amounts of ozone (less than 50 ppb) are not your best choice.”
Could you share us your understanding?
Hi there, your second link from California doesn’t state your quote “Blueair’s ionizer does produce ozone, so if you have breathing-related issues, you’ll want to avoid this air purifier.” But I don’t see that quote anywhere there on that page; and that list itself specifically endorses Blueair as an approved machine for California as it emits almost zero measureable ozone, as you say only 0.003PPM, which is far under even the US limit of 0.05ppm. So again I still don’t see any concern, I still haven’t seen one credible independent report saying there’s actually ozone emitting from these machines. And as I mentioned, Torana says their study showed LESS ozone in the room with Blueair, not more. But let’s try to get that data from them…
Thank you again for your response!
Sorry, the link 2 I was supposed to post is below.
http://air-purifier-review.toptenreviews.com/blueair-600-series-review.html
Here they say “Blueair’s ionizer does produce ozone, so if you have breathing-related issues, you’ll want to avoid this air purifier.” on the 5th paragraph.
Once I get data from torana, I will post here.
That review is just quoting everyone else, not doing their own testing. I guess we have to stick with the data about incredibly low ozone of 0.003ppm, basically non-existent in my opinion. I am very aware of ozone risks but I still definitely don’t put Blueair in the same category as many other ionizing machines — especially any machine that has an “ionizing” button feature…
Torana shared me the data, which is the research from California that I linked before.
http://www.arb.ca.gov/research/indoor/aircleaners/certified.htm
For me this is “list” than actual test result “data”, but anyways I’m convinced Blueair is not ozone producing machine.
Thank you very much for having been answering to my questions! Now I decide to buy Blueair.
Here’s the direct Blueair response about ozone http://us.blueair.com/clean-air-resource-center/faqs
You bring up some good points and I have also read elsewhere the concern about Blueair not being as effective when the filters are dirty, however Dr. Saint Cyr’s tests with his Blueair using non-new filters has allayed my concerns.
With the availability of low-cost particle counters I believe this is a must-have investment for anyone who is concerned about their indoor air quality.
Thanks. bought a
PHILIPS飞利浦AC4072/00空气净化器 55平方米（金属白）
on amazon due to its being the most competitive and well reviewed HEPA purifier.
definltely come back again. thanks again.
Any test results for PHILIPS air purifiers ? I spent quite some time trying to find some but all in vain… Please email me at postevg@rambler.ru if you have any. Thank you in advance!
Sorry, no!
Sorry, no!
Thank you for your blog! For your Hunter 31125, where do you buy filters from? I am looking for an air purifier that isn’t too expensive, but only feel I should buy one if I can easily get the filters. Thanks!
I don’t think this is sold anymore, I haven’t used in a couple years. You should still try Sundan, I think or just online.
Thanks for the good article! I noticed you mentioned “Ozone ioniser”. I am not sure if you mix up “ioniser” and “ozone generator”. Wiki explained the difference: http://en.wikipedia.org/wiki/Air_ioniser Or do you mean both are not recommended?
Based on the Shanghai air purifiers test you posted in another article, Daikin and Sharp are less expensive and of relative good performance compared with others provided in the market, but both have a kind of ionizer, should people avoid these two products?
I am not the super expert on this sub-topic but as far as I understand, ionizers in general are not a good idea and no good air purifier needs it. All you need is the HEPA! Most data I’ve seen on any ionizers — anything that actually creates more ozone in your home — show it’s is a bad thing. But usually those machinese with that feature have an off/on button for the ionization.
Sharp’s ionizer tech (called Plasmacluster) does not produce ozone. It should be safe.
Hi Richard,
Thank you for your article. The link to Hunter 31125 is not working. Do you have any idea where to get one either from a brick and mortar store or online?
thanks,
Simon
Sorry, no. I believe it’s now an outdated model… But I’m sure they would have others. I saw some recently in Sundan store in Sanlitun Village mall
hi
what about air -o – suiss air cleaners ? canno find hunter purifier but foung these ones .
Brand: Air-O-Swiss
Model Price(RMB) Filter Price of Filter
P350 1595 HEPA about 600
P355 2999 HEPA 700-800
P380 1999 HEPA about 700
thanks
lucy
Sorry, I’m not too familiar. Look for consumer reviews at Consumersearch.com or other sites (Amazon reviews…)
I’ve seen Air-O-Swiss in a mall here, one of their models uses a carbon cloth filter which is supposed to be quite effective. However, I was turned off by the high filter replacement costs (plan on changing filters twice a year if you’re in Beijing).
Hi,
I am wondering if there are any home air purifiers out there that are rated for 2.5 micron filtering. It seems that most of the air purifier’s threshold is 3 microns which could explain why your rooms aqi didn’t drop all that much on really bad days. I believe all the units you tested are .3 Finally, does anyone in this thread pay for a consumer reports subscription. It would be interesting to see how they weigh in on this issue. I would not be surprised if this issue eventual doesn’t become a major tort in the sates as ex pats age and come down with lung cancer, stroke etc. etc.
In general, the actual definition of HEPA is that it filters >99% of particles 0.3 microns (PM0.3) That’s the test. Same goes for the mask testing. Those particles are actually 10 times smaller than PM2.5, so just by definition a HEPA filter is filtering out EVERYTHING bigger than PM0.3.
Wait, I am being math illiterate above. 2.5 microns is bigger than .3 Duh! So the answer to the lack of reduction to the AQI on really bad days must relate strongly to the speed of air recycling relative to the higher starting point and constant influx ratio of pollutants. Naturally, it would be the best, as you note, if the filters were new in all test cases. In any case, I wonder if the company giving you the loaners would loan you several of each. That way, you could try to iron out the total CFM ratio relative to starting pollution level to at least the functionally practical point of diminishing returns. A fair comparison, then, between both models(or all 3) could be made. The really interesting point, however, is getting to that diminishing return algorithm. It would potentially illuminate that the direction of air purifier technology is mis-aimed towards increasingly expensive and more efficient single units as opposed to multiple cheap smaller units.
After reading this article, we are almost buying Blue Air. But I would like to ask one question for you since my wife is really keen to reduce the PM2.5 index lower than 35 which is recommended figure from my country’s government.
I am very curious if any air purifier can achieve this goal with current air situation in Beijing (today’s index was over 500) and also what is the ground for this number of below 35. I mean 35 might be too high standard for normal life. Perhaps buying another Blue Air might not meet this goal and we still have to keep buying another one…
So as a reference I would like to know your home’s PM2.5 index for very bad air day and for normal day if you have. I checked your chart in this article but I didn’t get any PM2.5 index.
I think it’s too difficult to think of air purifiers in terms of an actual number. It’s just percentages: in my house, I have 80% reduction in air pollution compared to the outdoor air. So essentially with the average annual PM2.5 concentration around 90-100, in my house it’s only ~20. Blueair is just as good as any other: you may need more than one machine to achieve your 80% reduction goal. And buy your own particle monitor, they’re getting cheap these days.
thanks for your quick response. Now we have two air purifiers and one day we borrowed the machine and checked the Index. At that time outside’s index was 400 some and in our home was 75 so our two machines shows over 80% reduction performance as well.
So we are guessing that if we buy one more, it logically will help to achieve less than 35. Even though we know it is really complex formula to calculate this index with many other factors and nobody can assure it.
Anyway we will try to get one more and see how it will work.
Hi – had my father in law visit us from HK and we had all the windows closed with the filters (IQ Air, Blue Air, etc) on full blast. He’s the kind guy that keeps windows and screen doors open all the time so living in our house closed off from the pollution still made him uncomfortable. After returning to HK, this is part of what he had to say:
“Last night in bed I thought about the air quality problem in your house. The thing I concern most is the fact that there is no outdoor air in your house. I understand the reading in your house may be 2000 and outside is even worse. However, I felt there is a lack of oxygen in your house and the whole house is filled with carbon dioxide which is harmful to health. Therefore to breathe polluted air is better to breathe air without oxygen.
You may say there are several air-purifiers in the house, but they are purifying carbon dioxide only which is no good. My church brother Ah Wai ( the one who fixed a sliding table in my shoe cabinet) he is a technician and he used to install air purifiers at peoples home and hospital Intensive Care Units. He said outdoor air is pumped in through a hole in the window, which is then connected by a tube to the purifier, then fresh air comes out from the purifier into the house. For your purifiers, no outdoor air is sucked in and they are purifying carbon dioxide instead.”
Any truth and / or risk to increased CO2? Please keep in mind we have 170m2 flat.
Thanks
Hi there — no, I’ve never heard of that issue from any researcher or reviewer anywhere. No house is perfectly sealed and there’s always air leakage as a natural part of any standard building. That’s why if you don’t do anything inside, the indoor air PM2.5 will rise and fall fairly consistently with outdoor air. I worry a lot more about indoor VOC and formaldehyde than any CO2, so no matter what, it is important to occasionally open those windows!
Hi : I stay in Delhi (India()and need an air purifier for my home room (room size 12 feet *12 feet). I don’t have any pets but pls do consider air pollution level and the recurring cynys/bronchitis I keep getting. I’m confused between IQAir Health plus 150/Allergen 100.of Blueair 270E. Blueair is 50% cheaper than the siad IQair Models
Would appreciate your opinion helping me make an appropriate buying decision
I’ve been researching on air filters too. I’ve been skeptical about using big brand filters such as blueair and IQair. It is true that their systems are widely used and tested. But teh problem with these systems is that the consumer is tied to their filters which are actually quite expensive. Users therefore will be hesitant to change the filters on a more regular basis, which will eventually render these machines ineffective anyway.
Usually bad air will affect the whole house and not just a single room. of course it doesn’t matter too much if one is living alone. But it will be quite hard on the pocket to purchase these machines for the whole family.
I chanced upon this: http://filterafan.com/ and the concept makes use of a regular box fan, with a generic panel filter (meaning you are not forced to buy from a single brand or the manufacturer of the filter machine) A good HEPA panel filter will cost around USD 9 to 15. And the startup cost for a single machine will be about USD60.
I’m thinking this might be a good solution for the above cost/efficiency concerns.
Also, I’m wondering whether putting 2 of such low cost machines in a single room in really bad air conditions will be more effective than using lets say a single blueair or IQ. Since 1 IQ or BA can only reside in a corner of the room, but two of these can be placed in two corners of room moving air in a same parallel direction, and might even exchange the air in the room faster. But these are just my guesses. Need someone with a proper particle monitor to test it out.
Loved your review!
Have you ever heard about Zonair3d’s products?
Used also by Doctors without borders, NGO’s, as an operating theatre/Clean room (which have the most aseptic sphere possible).
Also, wanted to know where did you get the PM monitor?
Did you try also with gas monitor?
Thank you!
No, I haven’t heard of Zonair3d, it’s hard to keep up with them all! Regarding my PM monitor, I bought the cheaper Dylos from the USA, measuring PM1 and PM5…
Hi,
I have been through your reviews about air purifiers, and I loved them, pretty good, full of insights.
I have myself been interested in this topic recently as I will certainly invest in one of those devices soon.
Actually I had a close look at IQair, BlueAir, Austin Air, and some other.
One comment I would make about blueair, is related to their mono-filter design, to me this impact the longevity of the filter in a dusty environment, and I eventually make its operation more expensive than other on the long run. Based on your experience with Blueair, what do you think ?
At the opposite, I do like Austin Air’s design, even though it is only a 2 filters, at least there is a pre-filter, cheap to replace, and vacuumable. On top of that their core filter seems to be quite strong and elaborated, with 15lbs of carbon mixture, which is actually 3 times more than IQair W5, and well the HEPA filter, is an HEPA filters as others with the usual 99.97% of particles >= 0.3Microns caught.
At last they advertise a 3 to 5 years lifetime for their core filter, which is better than IQair advertising 1 to 3 years for their HEPA.
About IQair, I like their multi-filters design, even through their filters are quite expensive. Actually I have seen that they have a pre-filter option called PF40, which can be set under the machine at the air entrance to filter the coarse dusts. This filter is washable and vacuumable and I believe a good option to increase the main filters life. Is this something you use ?
My 2 cents.
Regards.