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pan567 t1_is872x4 wrote

Bear with me, as I am about to geek out a bit.

I have/have had more than a few air purifiers in my day, but the only one I consider BIFL quality is my AllerAir Pro 6, as it has a stainless steel body, uses a commercial fan, and is built in the USA. It is appropriate for extremely polluted air, has enough airflow for the largest of rooms, and is very appropriate for use against VOCs. (However, it has some notable downsides, ranging from purchase/operational costs to its terrible 1990s-era aesthetics to the absolute lack of basic features. Mine also weighs ~60 pounds, and you need to turn it upside down to change the prefilter. That said, its performance and its holistic coverage of the various types of air pollution is just stellar.) AirPura is another name that produces a purifier with the same design philosophy (and it has most of the same downsides). Austin Air is also often considered to be very good. Alen is another that builds an excellent product (BreatheSmart line) and, despite having way more electronic components and advanced features than the others mentioned, they have a very solid reputation. They also deserve credit for producing a unit that moves a ton of air through a very restrictive medical grade HEPA filter, yet still manages to be quiet, and with great efficiency. Their form factor is also great. Oransi also made a domestic product (EJ-120) that had a good rep, but they recently continued it---the company said they are going to release a replacement in the near future.


I own or have previously owned products from Medify, Levoit, Whirlpool, Honeywell, Coway, and BlueAir, which are some of the common makers often mentioned in reviews. All of these brands offer some pretty good product lines, some of which utilize excellent quality HEPA filters, have a lot of airflow, and do a good job at reducing PM1/2.5/10 levels (but note that they are not very effective with VOCs). However, these products are generally imported, the fans are not the most robust, the cords are not always durable, the construction is generally plastic (with some exceptions), and they often have a ton of electronics built into the unit, which can and sometimes do break. (I do have a very basic Whirlpool purifier that is about 15 years old and running strong, which deserves mentioning.)

That's not to say these products are bad, but it is to say that many of the air purifiers presently on the market often seem to prioritize other areas above longevity. Right now, the hot thing is putting PM sensors on purifiers that are then used to control fan speed, which is (functionally speaking) a terrible idea. Smart capability is also huge, as is more emphasis on less ugly designs (see my note above) that blend in better with the surroundings. Further, the price of many of those products is stellar, and their ability to filter particulate matter from the air is pretty solid. Medify, Levoit, and Coway all deserve special mention here because they offer H13 (and, in some cases, H14) medical grade HEPA filters on affordably-priced units.

I probably went a bit overboard here, but I hope this is of help.


RWBreddit t1_is8c44x wrote

Not overboard at all. I enjoyed reading that. I’ll read anything you can advise me on regarding this topic.

Some recent blood work I had done showed that I have some allergen sensitivities, with dust mites and cat dander being the worst. I have both of those I’m my home. My doctor told me to spend the money and get a proper air purifying unit. I’m all for spending money for cleaner air that helps make my sleeping environment clean so that I may find more fulfilling sleep.

I’m not necessarily looking for BIFL I suppose, just products that truly do what I need and do it well. Longevity, features, aesthetics, affordability, etc are all non-priority variables that while aren’t entirely unimportant, are not really a concern.

I really do appreciate that reply. Lots of good info and I’m glad you shared it. Thanks!


Middle_Name-Danger t1_isre30s wrote

Look into Austin Air. Not cheap, but they’re probably the best mix of efficacy, durability, and design simplicity.


useless_bucket t1_itnyxoy wrote

I've got an austin air. Seems good but not looking forward to the replacement filter when I need one.


ListofReddit t1_itby8ft wrote

I’m looking into Levoit but wondering how often these filters need changed because they seem a little pricy


pan567 t1_itc9xqo wrote

tldr; Levoit makes good products at a reasonable price, and their filters are good quality--which model are you considering? Levoit recommends 6-8 months on most of their products, I believe. I would also recommend considering the Coway 1512 Mighty and Winix 5500-2, both of which I believe are 12 month intervals and, if filter costs are a problem, have some good third parties that also offer filters for them (not certain about Levoit in this regard). The Coway filters, even the factory ones, are very inexpensive.


in detail; Getting into the nitty gritty, it's hard to say exactly when a HEPA filter needs to be changed without a standalone air quality meter (and, to some extent, the ability to measure airflow through the unit itself). HEPA filters actually get more effective at capturing particulate matter the longer they are used. Then, after a point, their filtration efficiency falls because it gets clogged to a point where airflow through the filter becomes more difficult and decreases. This process gets expedited if extremely large particles cover the outside of the HEPA filter, so a lot of makers add reusable prefilters that capture hair, fur, and dust--clean these often and this can prolong the life of the HEPA filter (to a limited degree) and also the life of the unit (as the fan motor isn't working as hard).

The speed in which the above happens is highly dependent on the environment in which it is used and frequency/speed the unit is ran (Side note - I recommend running these units around the clock at the highest tolerable speed.) So, generally, they provide a rough filter interval estimate to try to account for average conditions. In a highly polluted environment, you may need to change it more often. In one with less pollution where you are constantly cleaning the prefilter, you could probably get away with longer change intervals (although some makers do require you to change the filter on their interval to maintain the factory warranty.)

Now, another thing to think about is carbon. Many filters today have carbon pellets impregnated into the HEPA filter, where a single filter contains both the HEPA + carbon components. The amount of carbon in most consumer units is very, very small, and its ability to impact VOCs for any prolonged period is extremely limited. This carbon will generally exhaust long before the HEPA portion of the filter, and some makers do appear to base their filter change intervals on this. With Levoit and most of the major manufacturers, I do think it is important to note how they are very much oriented towards the filtration of particulate matter. Their ability to reduce unwanted scents, and especially harmful VOCs (e.g., benzene, formaldehyde, etc.), is very, very limited. Arguably, particulate matter is going to be a bigger concern for most buyers, but if something is needed specifically for VOCs, a different kind of filter should be considered.


ListofReddit t1_itdtbqm wrote

The coway mega would filter roughly every 20 minutes. Goes for $190 right now. The winix C535, 5300-2, and 5500-2 would do every 20 as well. C535 is $150 compared to $200. What would the major differences between those 3 be? I’m here for overall cheap upfront and maintenance.


pan567 t1_itf5qdm wrote

I can't speak to the 5300-2 and 535, but Winix does make good products, so those are probably good units. With respect to both the Mighty and 5500-2, both have pretty reasonable running costs. Each does a bit better than the other in different areas.

The 5500-2 and Coway Mighty separate the carbon filter from the HEPA filter, which, to me, is an advantage. The 5500-2 has two different carbon filter options-one that is a carbon mesh, and the other which has actual carbon pellets (the latter being better), whereas the Coway is only the former. The Coway brand filter should be a bit cheaper than the Winix brand. Filter Monster, and other respectable third party makers, should make third party replacements for both (I've tested a Filter Monster product for a Whirlpool and found it to perform equally as good as OEM against PM2.5). Both are rated at 12 months and, if on a budget, IMHO, stretching it to ~15 should be just fine provided you are frequently cleaning the prefilter.

Probably the biggest difference between the two comes down to energy usage. To my understanding, the Coway is more energy efficient on lower fan speeds, and the Winix more efficient on higher. I feel running on higher is always a good thing (if the noise is tolerable), so if you are going to run it on a higher speed, this favors the Winix 5500-2.

One other option to mention, if on an extreme budget, is the Corsi-Rosenthal box. This is effectively a box fan taped to MERV-13 filter(s). It is not very pretty to look at, but it is very effective with respect to filtering particulate matter. That said, while its up-front cost is much lower, energy consumption is higher.


ListofReddit t1_itqirwz wrote

I can get the 5500-2 on Amazon for $150. How much do these replacement filters typically go for?


ListofReddit t1_iufhs71 wrote

Found a winix d480. Wondering if it’s any good compared to the rest? The only complaint I see is that it has a carbon foam.