IQAir - GCX MultiGas

Most air purifiers produce more of a rushing air sound, which is different to a large fan. And many can be quite loud on their top settings—examples are IQAir, most Medify Air models, and Winix. You could [build your own Corsi-Rosenthal box](https://engineering.ucdavis.edu/news/science-action-how-build-corsi-rosenthal-box), which is powered by a box fan. See also the related subreddit: r/crboxes If you want to listen for yourself, you can go through HouseFresh's YouTube playlist of air purifier sound tests. A few models may not be available in the USA or have been discontinued. Link: [https://www.youtube.com/playlist?list=PLOuKERCL33BQ1VAbZmUMzY6sY8MYsfO1r](https://www.youtube.com/playlist?list=PLOuKERCL33BQ1VAbZmUMzY6sY8MYsfO1r)

Most common air purifier brands do not have enough nor the right type of sorbent media for gases, vapors, or odors. Sorbent media in air purification = activated carbon, activated alumina, or synthetic zeolites. Heavyweight sorbent media purifiers are very expensive, very loud, and clean the air more slowly than particulates-focused units. This is due to the need for ["dwell time"/"residence time"](https://www.airscience.com/carbon-filters) and the thick media beds. The two major heavyweight brands in the USA & Canada are **Airpura** or **AllerAir**. You want to look for models with 15 lbs.+ carbon canisters. Most standard options for these purifiers are plain/chemically untreated sorbents, which do *not* have high removal capacities for all gaseous "species". This sometimes presents problems where an odor emanates from the sorbent bed (possibly the not-well-adsorbed acetaldehyde) or there's a spike on tVOC monitors despite a reduction in odors. Assuming you don't live near a refinery or have really bad air chemistry otherwise (e.g., from fires), you may want to look into potassium permanganate (KMnO₄) impregnated activated carbon from Airpura or AllerAir. You'd have to contact the respective company first to specify this. KMnO₄ works in part via redox (reduction oxidation) reactions by breaking down certain gases. This can be problematic in unknown and/or highly complex air chemistries where resulting gases may be problematic. It can also off gas as it saturates or loses efficacy.

Your best options are likely the IQAir GC or GCX series purifiers. As for the exact model, you may want to choose one with potassium permanganate (KMnO₄) impregnated carbon or alumina. See [my other comment in this thread](https://www.reddit.com/r/AirPurifiers/comments/1oco7i5/comment/nkoz4yw/).

Both the IQAir GCX and GC series use a pre-filter that's EN 1822-1:2019 Efficient Particulate Air (EPA) E11. IQAir calls this "H11", but it is really EPA E11. Both the GCX and GC are meant for gaseous removal, so it makes sense to use EPA E11. This prevents excessive pressure drop. The IQAir GCX MultiGas is very good for gaseous removal, although it's expensive compared to heavyweight sorbent media purifier brands like Airpura (max 26 lbs. carbon canister) and AllerAir (max 34 lbs. carbon canister). However, I'm quite certain the GCX MultiGas pre-filter has far more surface area compared to mechanical filters present in comparable Airpura and AllerAir models. Do you have elevated levels of gases/vapors/odors (includes VOCs)? I would recommend having air testing performed with Gas Chromatography-Mass Spectrometry (GC-MS) analysis *first* to determine the gaseous species in your airspace.

I would add IQAir to this, especially the Multigas GCX (emphasis on X, it's superior to the GC which is already a great unit.) Oransi has a standalone carbon model as well. But yeah this list including your comment is very complete. I spent months researching and created a comprehensive brand list and narrowed it down to the exact same brands you mentioned for actual decent VOC filtration. Real world performance is a different issue however and the one thing I would emphasize to OP is that 2,000 is a *lot* of square footage and these types of purifiers are very expensive and if you're looking to consistently purify the entire dwelling then you'd need at least a half dozen 250CFM units to make a difference. It will be expensive and loud and the filters will saturate and need replacement very often if you have a smoker nearby.

I ordered the IQAir MultiGas, it’s been running all day, still have a crazy headache and sore throat. Feel like death. How are we going to live like this??

Ah crud, bought another MutliGas too. Both have been running all day, one in the living room, one in the bedroom. Headache and sore throat gone at home, but comes on when I’m outside for 10 mins.

If money is out of the question. IQ Air Multigas.

That IQAIR model is a good one for a mixture of particulate and VOC filtration. You can also look at other companies like Austin Air, Aller Air, or essentially any other "steel can" style air purifiers. They'll come with tens of pounds of activated carbon and HEPA filtration but they are loud and expensive. But they are effective.

Pro X does have activated carbon but not a lot. Just a few lbs and they're connected to the HEPA filters meaning if you want to run it under ideal circumstances you'll have to replace the filters when the carbon is full which happens way faster than the HEPA portion. That's one of the nice thing about the IQAIR unit is that it has separate filters. However the PM2.5 particulate is the most immediate danger from the smoke and the Pro X will absolutely breeze through filtering that. It'll probably do ten or more air changes per hour in a room that small.

I have Austins and IQAir MuliGas. The Austins were recommended by a clinic which treats individuals with extreme chemical sensitivities. You want a unit where the fan feeds the filters (1st in the chain) to avoid contamination from the fan itself. No filter is going to eliminate all VOCs.

I have a couple of models: Immunity Machine, Healthmate Plus, bedroom machine. There have been some reviews stating that Austins are slower at clearing a room of particulates. My main concern is VOCs and since I run 3-4 filters in each room that isn't a concern for me. Am now testing the immunity machine. Seems to do a much better job with VOCs, although final results will take a while. What is your concern with IQAair?

I run 3 filters, Austin and IQAIR, in each of 2 spaces - one 300 square feet the other 600 square feet. If the air is poor outside my Purple Air sensors will still show green. However there are so many chemicals in wildfire smoke, particularly if structures have burned, that they don't get everything. I am sensitive to terpenes and right now they don't help with the Camphor tree flowers. So they can greatly improve air quality but don't expect all VOCs to be removed from the air.

I use Austin Immunity machine and iQair GC Multigas units as VOCs are a major concern for me. Not rated.

Iq air MCS hands down. Entertain no other option, its ability to filter is down to the smallest size I can find.

You’re right, my bad. Guess is a colloquial name we’ve given it in my house. I’ve had two for 9 years and can’t imagine life without them. We do vacuum the bottom pre filter every two weeks to prevent dog hair from reducing flow. I do bring a medium sized new version Air Oasis when traveling.

AirDoctor didn’t seem to do anything for me so I sold it and got an IQAIR which seems to help quite a bit. The replacement filters are expensive At the time I bought it it was the only purifier capable of trapping mycotoxins which are like 0.003 microns or 0.03 microns They have a hyper-HEPA filter system I run mine on high 24/7 They are medical grade and even used for clean rooms. They are also the only one I’m aware of that you can break down to properly clean out mycotoxins and take it with you when you leave mold. My humidifier, vacuum and old air purifier will have to go in the trash

Unfortunately the most effective purifiers are not cheap. I bought an AirDoctor because the IQAir was too expensive. It didn’t seem to do anything, so I ended up selling it and buying the IQAir in the end. The IQAir MultiGas was most effective (of the IQAir lineup) against VOCs like mycotoxins last I looked. I supplement with Microbalance EC3 candles

If you looking for filter out dust you need the one has big and powerful fan but if you need one to filter out VOC and a microscopic stuff you better of looking for multi layer filter system with HEPA , I have used Coway for dust and Dyson formaldehyde for microscopic and IQAIR multigas for road traffic pollution next to my apartment!

Have worked through all sorts of filters over the years. Quick answers (just did a longer post to another similar question): A - Dyson, no way B - nothing with an ionizer or anything that tries to sell you on electronic or charged particles. C - the ½ or ¼ inch charcoal filters in most purifiers are worthless. If VOCs are the issue, just open some windows. If you can’t, then check out IQair Multigas, and the Austin Air unit with about 30 pounds of charcoal. D - you have to choose between HEPA (most of those on your list), or medical grade like the IQAir. The later cleans MUCH MUCH more, but they cost 3-4x as much (although their replacement filters last a long time.) Good luck and success!

We have the health pro, the compact, and the multi-gas. Wish we hadn’t the compact (was trying to save some bucks) as the health pro is better. We use the multi-gas near the kitchen. They are all great, but we like the health pro the best. Also, if you are focused on VOCs, then you want the multi gas, or AustinAir makes a great one with about 30 pounds of charcoal if memory serves. Not sure about any of these and Voc’s though. But for particulates, viruses, etc, these units are amazing.

Yes to IQAir - didn’t really help allergies or sleeping until I went past HEPA. These are the best.