4200i PureProtect Pro

Hi, I bought the Philips AC4221 air purifier last week and I'm using it in the living room and it covers around 700 sqft of area. It works pretty well. I just want to let you know that this air purifier maintains a PM 2.5 level of ~50 in auto mode. But in turbo mode, I have seen it going as low as ~10. I bought it from Vijay Sales (offline) for ₹23,499.

The Philips has the highest CADR and is quite silent, it also has a gas detector, I have it and I recommend it to you. Original replacement filters cost about 60 euros in Europe.

In Europe there is only the 4200 in black like mine and in silver (ac4221, ac4220). Of the 3200 there are 3 colors: brown like mine, black and silver-white (ac3210, ac3221, ac3220).

I have 3 philips 4000i 1 philips 4200 and a coway airmega 50.

A Philips 3200 would be better; that one's for small spaces. The 4200 isn't worth the price. It's exactly the same as the 3200, just with a gas sensor and a filter with more carbon. (I have both.)

I have both and I recommend the 3200. The only difference between it and the 4200 is that it doesn't have a gas sensor and the filter doesn't have a double layer of carbon, only a single layer. In any case, it's not enough carbon to be of any use against gases. In fact, you can use the 4200 filters in the 3200 and vice versa; they have the same dimensions, one is just slightly thicker on the inside. I'm currently using the FY3200 filters in my 4200.

The 3200 is a good option. I have it and also the 4200, and they don't make any high-pitched noise.

lemme share some of the research I did while choosing mine 3ish weeks ago. What you want to look at is CADR. This is measured in m3/hr so ideally you could simplify your search and choose the highest number you find in your range. The Sq ft number is not reliable in Delhi in my opinion. As my budget was also 20K i short listed the following based on what was available at local retailers nearby: 1. Honeywell P2 - 550 CADR 2. Phillips 4221/61 - 600CADR (I bought this) 3. Qubo 1000 - 600 CADR 4. Honeywell U1 - 700 CADR. (most expensive) Most people would be okay with a 550 CADR but my room is tall so i still see the AQI go to 200 at full.

First off, Corsi Rosenthal Boxes if you're in the US is an easy homemade solution that doesn't look pretty but beats almost any commercially available air purifiers. So look in to those first if you're in the US. But figuring out best ain't really that simple, because one that covers a 28 m2 area might require that air purifier to run at full speed in order to do so. Generating a lot of noise. So you might want something that can filter a far larger area instead so the fan can run at low speeds. Then you have to consider the price of replacement filters. But also you're going to own it for a lot of years, so long term availability of replacement filters can also end up being a big deal. It would obviously really suck owning a unit only to figure out you can no longer get new filters. Personally I looked over all sorts of different units, but in the end I ended up with a Philips 4200. It ticked all boxes for me, it covers a much larger area than I need but that allows me to keep the fan speeds low enough that they're not annoying. Filters are moderately priced and last over a year, and they're available.

First off, "best" is whatever has the highest CFM rating. Whatever pushes the most air is pretty much best. Corsi Rosenthal boxes are "best" as they can easily push 1000 CFM. But in reality you choose based on other metrics, such as price range, availability of filters, price of filters, how often they have to be changed, how quiet they are and so on. I picked a Philips 4200 Pureprotect, to me this was best, as it was high CFM rating, auto setting and very quiet. While also having new filters available in my market for years to come. And personally I've tested it at home, where I don't notice much of a difference as air qualiy was pretty good in the first place. But also in the homes of friends who have dogs and I have asthma and react to them. Had a friend set it up a few days before his birthday so the air would be properly cleaned for a few days when I got there and it made a huge difference. Usually I notice symptoms after just a few minutes, this time I could spend hours at his house with minimal symptoms. But even if my unit is a quite expensive, good and quiet unit it still doesn't get close to the Corsi Rosenthal DIY boxes in terms of how much air is purified. Hope this helps, just keep filter price and exchange rate as well as availability in mind when you buy one and you'll be fine. And remember more air is better, filtration efficiency matters a lot less than just the air volume.

In many units the gas sensor is faulty or acting sometimes up. Moreover the amount of carbon in these filters is quite small. You would have to get more professional purifiers to really get gases gone (some editions of iqair). Against particles these filters are great and there are plenty of third party manufacturers of filters. 900 would be more audibly noticeable (small fan, higher frequency), 4200 having a sensor that is somehow useless, so choose the 3200. I would say they would reduce the smell of your furniture with its amount of carbon but don't expect it to keep reducing it throughout the year when you're getting more furniture.

I wouldn't use ChatGPT or another AI tool to find a purifier. It's frequently wrong about specifications or other details. And I wouldn't recommend Dyson. Their units provide poor particulates cleaning for the money. Per **Rule 4: Information For Air Purifier Requests**, I don't know your country of residence or your budget. I'm guessing you're in Saudi Arabia. The acronym you mentioned is CADR (Clean Air Delivery Rate). As u/timesuck said, purifiers aren't good at reducing visible dust particles as they're large and heavy compared to "invisible" pollutants like PM2.5. Vacuuming and dusting are the better solutions for visible dust capture. I would recommend a bagged vacuum with a HEPA exhaust filter from brands like Miele or Sebo if available. Another important matter is sound output. Infants and young children shouldn't be exposed to overly loud purifiers. According to a *Pediatrics* article, USA hospital nurseries have a recommended sound limit of 50 dBA. Because of this, you'll want to oversize a purifier so you have ample CADR without being too loud. For rooms measured in meters, I would select a high CADR. If PM10 and PM2.5 pollution concentrations are high, I would go with a CADR six times the room's volume in m^(3). Let's assume the nursery has a 2.4 meters high ceiling. Room volume is then 72 m^(3). 72 m^(3) × 6 = 432 m^(3)/h CADR. I would tend to recommend the Coway brand first as they're high quality, energy efficient, and relatively quiet. Something like the **Coway Airmega 400** (top CADR: 677 m^(3)/h) would be great. But it's also expensive. A good choice would be the **Philips Smart Air Purifier PureProtect 4200 Series** (top CADR: 600 m^(3)/h). Keep in mind the CADRs listed for these purifiers apply to the highest airflow speed/setting only. Lower settings have lower CADRs which reduces cleaning effectiveness. Lastly, these two purifiers have little capacity for capturing gases, vapors, odors, or VOCs. This is due to very little activated carbon by weight. Unfortunately you need many pounds of activated carbon or other sorbent media. Heavyweight sorbent media purifiers are very loud and very expensive.

For conventional air purifiers, your budget is too low due to New Delhi's extreme pollution events. I would recommend a purifier whose CADR meets or exceeds your square footage. So a 500 sq. ft. room (with an 8 ft. ceiling) needs a CADR of 500 CFM or greater. A CADR of 500 CFM is equal to 850 m^(3)/h. You would need *two* Philips PureProtect 4200 series purifiers (CADR: 600 m^(3)/h each) to meet or exceed minimum CADRs. You can build your own large Corsi-Rosenthal boxes with PC fans. CADRs will depend upon airflow speed, # of PC fans, # of filters, and filter size. In the USA and Canada, MERV 13 or MERV 14 filters are used. But these may be non-existent in India. A guide: [https://itsairborne.com/pc-fan-corsi-rosenthal-guide-a611dabf7e0c](https://itsairborne.com/pc-fan-corsi-rosenthal-guide-a611dabf7e0c)

Would highly recommend philips 4221 in the budget and ease of use for wifi. Plus excellent CADR