[phamilyman]

Friends,

It is that time of the year when north of India chokes courtesy stubble burning in Punjab / Haryana. So many of us buy air purifiers - this thread examines a few popular 10k models and gives first hand recommendation in one place to aid BHPians considering to buy their next one.

For the lazy ones, here's the TL;DR device recommendation as per YOUR mindset:

• Middle class or environmentally conscious person wanting cheapest device with heavy use: Philips AC1215
• Middle class person wanting cheapest device with limited use: Mi 2s
• Middle class geek who wants to know the exact extent of the air quality: Mi 3
• Money no bar: Sharp Plasmacluster series which solves COVID and AQI issues
• Modest office in non AC premises with constant flow of people coming and going: Mi 2s
• Someone working in an office or business with Covid19 exposure possibility: TruSens Z-1000

What would I buy again if Covid hadn’t happened? Philips AC1215 primarily because of Xiaomi's forced replacements of a filter that's HORRENDOUS for the environment!


As of November 2020, I have not changed any filter till date, but I clean the filters every 30-40 days religiously by tapping them or using old toothbrush or running water for pre filter.

Pre filter is really critical since without it the HEPA filter deals with the Guragon dust, which is simply overwhelming. I wouldn’t recommend any device without it, except the Mi3. Their design has a sort of integrated pre filter.

One big issue is that EVERY company, even Philips, does not mention the exact HEPA rating anywhere. XIaomi was the biggest culprit with their initial models being EPA E12 rated but most people bought them blindly because of the CADR.


Ever since the mad winter of 2016 where Gurgaon practically choked on Diwali, we have had a few air purifiers. This is my comparison after a long term usage:


Let's now look closely at the two major models, starting with the Philips AC1215:
Positives:

• H14 Filter: No one else in this price has one. Do note that Higher filtration efficiency means slower air purification! It is still cost effective – my filter is still so clean after 3 winters of daily use!
• Very easy to clean design with pre filter
• Separate HEPA and carbon filters. The activated carbon filter is for volatile organic compounds (VOC is like smoke or tadka). For people in Gurugram or Ghaziabad, the dust and soot is far higher than much VOC
• Air Quality indicator is very sensitive : on terrible days like today, the AQI indicator turns red as soon as I open the door / windows
• Super quiet: I can run the Philips quietly all night, but the Honeywell, is a bit discernible.

Such a clean H14 HEPA filter after 3 years!

Negatives / idiosyncrasies:

• Frequent filter cleaning requests
• Auto-switch-off LED display (not auto dimming)

Mi Air Purifier 3:


Positives:

• Real time measurement: Your room AQI is nicely visible
• Connectivity: Some geeks would love to observe the status via the app but i am happy with the display and do not want another connected device that can be hacked tomorrow. For me, this is unnecessary timepass.
• Silent with best in class CADR: The air improves quickly without much sound
• Looks the best by far

Live AQI, temperature and humidity! Gorgeous!

Negatives:

• Filter life remaining: You can see this statistic upon purifier startup. You can only use filters with RFID thus locking you into high priced filters. I disagree heavily with the assessment which is possibly an hour counter and not a sensor based system evaluation
• Hard plastic non biodegradable filter: The filter is practically a structural member! Its sturdy and would be a shame to throw away. I doubt this filter will degrade in 100000 years. Xiaomi should be shamed and forced to change their design.

Does this shiny filter look 48% used to you? It is, as per Xiaomi!

Now if you're like me - you're thinking - to hell with them, I won't change my air filter and maybe reset the device?!! But they are smarter!


I guess this RFID means you can’t purchase cheap replacements or use this one forever! Xiaomi will force a new filter on you!

Of course, if you arent too bothered about your environmental footprint, nothing else comes close to the Xiaomi in overall ownership!

The Mi 2s doesn’t get a dedicated comparison, which is available at the Mi store. The key differences are that it has no display, a poorer EPA (not HEPA) E12 filter. It works well for offices where people are coming and going regularly so you need quick filtration more than perfect filtration.


I haven’t compared Kent because of being too expensive on VFM side vs the Xiaomi or Philips series. At that time we bought the higher capacity device courtesy a shortage and hoping that it will be more effective in a larger room. But now we know that unless the fans are running (in winter?!) the clean air may not circulate that effectively in large rooms and lead to dead zones!


If you can’t source the Philips, the Honeywell is fairly decent too! I haven’t compared Honeywell in detail because the Philips is clearly better with a nearly similar price for the following reasons:

• Clearly quieter
• Better filters H14 vs H13
• Independent HEPA and carbon filters vs an integrated one for Honeywell A5

PS: MOD Request - I am creating a separate new thread since the discussion in the Home Appliance thread gets easily lost and hard to follow esp for non registered readers. Hope this is fine.

[extreme_torque]

Interesting comparison. I was planning get Xiaomi to reduce hay fever effects but that RFID thingie has made me think. Counting hours is a terrible idea as even my car's air filter looks cleaner than an air purifier filter in Delhi. Does it not work if you re-install the filter or it gives a warning and you can make it work? What if you were to take out the RFID tag? Its headed for landfill anyway.

[lapis_lazuli]

@familyman, "that" filter life, it's not derated just by hours. It is based on weighted AQI * time used* speed of fan and the rate of reduction in AQI starting from a threshold. Factual information.

[phamilyman]

Originally Posted by extreme_torque

Does it not work if you re-install the filter or it gives a warning and you can make it work? What if you were to take out the RFID tag? Its headed for landfill anyway.

I will find out in 3-4 months bhai Will try all those hacks then. I still have 52% usable life!

Originally Posted by lapis_lazuli

@familyman, "that" filter life, it's not derated just by hours. It is based on weighted AQI * time used* speed of fan and the rate of reduction in AQI starting from a threshold. Factual information.

My bad - do you have a link?

My take is simple - our car AC filters were often used for 30-50k km and they would often say - "it is still clean, keep it saar, I have dusted it"

No one ever had issues that way - why should I change my air filter esp when I am extremely OCD and painstaking in cleaning the filters by hand?

I could totally be wrong but i am too middle class to think otherwise - I am open to being persuaded by science, though.

[Sebring]

Being in a desert Nation we have tried every air purifier out there before settling on Sharp. They are the pioneers in this space. These even filter out the sand deposited during the notorious desert storm where the nano particles get into everything (Special Desert Sand Storm Mode, to boot). If anybody can import these machines it's well worth the time.

[drive_angry]

Anyone with any experience with Dyson air purifiers? they are very heavy on promotions wonder if they live up to the expectations. Thanks!

[ohaak]

I have been using the Philips AC4081/20 Combi Air Purifier & Humidifier for a while now. It does the job well and without fuss. There are newer models available for sure, but the point to be considered is the room size and air purification volume / rate in addition to availability of spares.

[sukarsan]

Most of my understanding of Air purifier technology and applications come from this blog by SmartAir . The blog led to the development of Smartair company, but their archives are a goldmine and has almost all the answers, along with the graphs and the testing methodology.

Originally Posted by phamilyman

Friends,

I have grappled with the question of HEPA filter replacement and below are the points where I agree and want to emphasize on-
1. Pre filter is mandatory. And clearing of Pre filter every month is very important.I clean out huge amounts of dust from the pre filter and these particles on HEPA filter does it no good.
2.Separate HEPA and carbon filters - Also mandatory. The problem at NCR does not require a Carbon filter. This will add to the service cost. Enough said!
3. MI is to be avoided at all cost. I don't see the necessity of having hard plastic non biodegradable filter. This is very strange as all standard air filters used the interwoven fiber based structure . The RFID concept is ridiculous. Mi is like having a car that just wont start when it time for servicing.

Points I disagree-

Originally Posted by phamilyman

Such a clean H14 HEPA filter after 3 years!

No way ! This does not make sense. I suspect a leak, but had there been an issue, then your air quality indicator would not turn blue. I am unable to explain, but 3 years in NCR is not the intended life of an HEPA filter.

Please check this study from China for reference images. (without prefilter). My filters (Philips 2882) behaves inline with above images.

Coming to the topic of filter replacement , I have the below 3 point approach:

1. Is the indicator on the filter taking more than 15-20 mins to go from dirty to clean an enclosed room? Then its time to replace.
2. Subjective analysis- Whats the color of the filter ? Is it black enough to justify a replacement? How long has it been? Are there some offers on filters? My thumb rule is 2 filters an year- one for the 'season' and another for 'off-season'.
3. Are there people who are sensitive to pollution? I had a baby in the house and a new baby justifies a new filter . Additional 2k is better than dealing with nasal inhalers later on.

Originally Posted by drive_angry

Anyone with any experience with Dyson air purifiers? they are very heavy on promotions wonder if they live up to the expectations. Thanks!

Dyson's is a vacuum cleaner company and their USP is the form factor. HEPA filters are generic technology available since 1940s . For more , please follow this study.

Originally Posted by lapis_lazuli

It is based on weighted AQI * time used* speed of fan and the rate of reduction in AQI starting from a threshold. Factual information.

wow, TIL. Makes sense . Thanks. This is something which can be achieved by simple electronics and is much better than time based counters.
However, from the work done by SmartAir, I understand that the replacement is not a binary decision. the efficiency decreases over time. So, the trigger to replace the filter is an arbitrary line in the sand and MI would much rather err on the side of caution(and $$) in identifying this line.
[/quote]

[DaiusPitar]

Background: I moved to Noida last year just after Diwali. Yes, great timing. That was my first trip to NCR at that time of the year. You can imagine my shock. It got me in to panic overdrive mode

I picked up 3 Sharp machines from FP-J40 to FP-J80 last year. I can recommend Sharp, especially the J80.

Then I came across this, The Sqair

Recommend checking it out. And it looks good as well as different from all others there. I picked one of this as well. Truly effective. Only does not have a built in AQI display and does not have an Auto mode. But gets you savings in return and

Also, since many of us spend time on the road, do check out Car Air Sanitizer. I got this for my Ecosport. The idea is to filter the air coming in to the cabin by the AC. It makes a hell of a difference compared to not doing this or not having an air purifier in the car.

I vouch for all the above after testing with this Kaiterra Laser Egg 2 Air Quality Monitor . Found this after reading this article

[warp_10]

Owned a Philips AC4025/10 model. Have heavy pollen and dust issues. This model has been extremely efficient and reduces my allergens to a great deal.

First freely available water became packaged. Soon freely available air would become packaged. These air purifier systems are bound to become way more common in the next 5 years.

[v1p3r]

Originally Posted by phamilyman

Friends,

It is that time of the year when north of India chokes courtesy stubble burning in Punjab / Haryana. So many of us buy air purifiers - this thread examines a few popular 10k models and gives first hand recommendation in one place to aid BHPians considering to buy their next one.

Very cool thread! I've been using the Mi 2 for a few years now, still works very well. I use it all year round, not just in the winters, so my room has the same PM count as rural Switzerland.

Originally Posted by DaiusPitar

Then I came across this, The Sqair

Recommend checking it out. And it looks good as well as different from all others there. I picked one of this as well. Truly effective. Only does not have a built in AQI display and does not have an Auto mode. But gets you savings in return and

Also, since many of us spend time on the road, do check out Car Air Sanitizer. I got this for my Ecosport. The idea is to filter the air coming in to the cabin by the AC. It makes a hell of a difference compared to not doing this or not having an air purifier in the car.

Smart stuff is very good, and efficient. I would not put too much store in the Car Air Sanitizer, though. It may seem good in the short term, but you're looking at a compressor (and associated parts) replacement if you use your AC a lot. If it were that easy to put a HEPA filter inline, everyone would do it.

Originally Posted by drive_angry

Anyone with any experience with Dyson air purifiers? they are very heavy on promotions wonder if they live up to the expectations. Thanks!

Useless for purification. Stay away unless you're spending money to admire industrial design art, in which case they're great.

Please do not set too much store by either the purifier's on-board air quality sensors or an app's readings. Most are very inaccurate. If anyone wants a free AQ monitor, PM me.

[J4J]

Originally Posted by extreme_torque

Interesting comparison. I was planning get Xiaomi to reduce hay fever effects but that RFID thingie has made me think. Counting hours is a terrible idea as even my car's air filter looks cleaner than an air purifier filter in Delhi. Does it not work if you re-install the filter or it gives a warning and you can make it work? What if you were to take out the RFID tag? Its headed for landfill anyway.

One of the newly launched Mi purifiers (Mi 2C) doesn't need any RFID.
It is the bare basic model without and smart features. It only has red, orange & green LED's. I've verified the readings with second purifier and they seem quite accurate (+-20 difference).

I've seen online that you can continue to use filters as the app shows a warning if filters time out(haven't personally tested it though).

If we look at these machines, they are basically a filter + fan combination to throw clean air out.
What only matters is that the filters must be of good quality.

I find Mi to be the best value for money. They are powerful compared to competition.
I've one Mi 2S from last 3 years and is doing good. It is on the same filter that it came with. I use a pre filter so larger dust doesn't get inside. I use it only on days when levels are > 200 outside. This is approximately 1.5 months of total 'on' time every year (Oct- Jan).

[Rajeevraj]

I actually have a brand that very few seems to have heard of but is apparently one of the top brands in the world with respect to air purifiers. The online reviews are also very good. Its a no frills model with 3 filters. Have been using for a year now. Was kind of an impulse buy. Have not changed any filter yet.

Coway Professional Air-Purifier, Special Green Anti-Virus True HEPA Filter (Sleek Pro (AP-1009CH)) https://www.amazon.in/dp/B07JZ94F9C/..._6QPLFbXFQSQPW

https://cowayindia.in/?gclid=Cj0KCQj...caAuH9EALw_wcB

As mentioned in the post above, air purifiers basically need to pull in air , pass through the filters and throw it out. The quality of the filters are everything. All the smart stuff, different colored displays and LED's are all jazz..

[iamitp]

Originally Posted by drive_angry

Anyone with any experience with Dyson air purifiers? they are very heavy on promotions wonder if they live up to the expectations. Thanks!

I have a Dyson Pure Cool Tower (2018 model). Although mine suffices, my girlfriend, who lives next to a heavily commercial area, had to return hers and settle for a Honeywell instead.

Dyson's USP for me is the beautiful app, sensor displays and graphs and smart home capabilities. If I was shopping again, I would probably get the Hot + Cool model which would be brilliant in cold Delhi winters.

The one major con for me is the expensive filter replacement.

[Maverick Avi]

Being born and brought up in Delhi I have never relocated and have been living here since last 40 years. I am much more aware now with all sorts of gadgetry and information that is available but I feel that during my schooldays when diesel vehicles ruled, pollution levels would have been equally drastic. I still remember taking in those diesel fumes in my school bus and still not hearing a word about pollution and AQI. Diwali used to be whole lot smokier due to crackers. Farmers used to burn paddy residue like anything. But still we were happy as nobody was quantifying the pollution levels and showing it day in and day out. So ignorance was a bliss.

My wife suffered from severe coughing in 2017 when pollution levels were all time high. Doctors said its due to ongoing pollution and prescribed basic anti allergics. I asked the physician whether room air purifier would help and he denied. Medications were not helping my wife so in a fit of urgency I got the much acclaimed Philips AC1215. It was a simple no nonsense machine which reflected the AQI using colors. Red, purple, pink and blue. The filters were also pretty easy to install and straight forward. It used to take 10-15 mins to turn blue from red in a closed room of average dimension. Personally, I never felt any difference in perceived air quality when I used to enter the room. During the next 4-5 days this was being extensively used in my wife's room but unfortunately her situation did not improve. We eventually took her to doctor again who changed medication to some steroids which ultimately provided relief and she was fine in next 3-4 days. What happened to my Philips Ac1215? I returned it on 10th day as it was bought from Flipkart.

So, for all those who feel a perceivable difference in air quality using one of these air purifiers I can say that Philips 1215 should be a good option. Also intended for those who would feel safe just looking at its colored rings going from red to blue. Technically these air purifiers work for sure but how effective are they at reducing the risk of pulmonary ailments in Delhi is something I am not convinced enough.