IQAir

GCX MultiGas

IQAir GCX MultiGas

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Overall

#131 in

Air Purifiers

according to Reddit Icon Reddit

Sentiment score80% positive
4
1
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Top Pros

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Last updated: Oct 7, 2026

Reddit Reviews

Reddit IconNumerousAssumption47
9 months ago

Hey, you and I are in the same boat. I had a baby boy at 31 weeks, now almost 5 month adjusted, and I went down the air quality rabbit hole hard. I want to do whatever I can to keep him healthy and developing normally. He sleeps with us in our room right now. I have a clean air kits luggable xl pc fan cr box and a IQair Health Pro Plus running on setting 2. Both run 24/7. This gives me a lot of air changes per hour and some gas filtration, while staying below 50 decibels. In the rest of the house, I have more luggable xls, smart air blast, iqair gc and GCX, Coway 400 and 300, and an Alen 25i. I think it’s important to get a standalone air quality monitor like the air gradient one or purple air zen. I run the hvac blower fan 24/7 to circulate air through the house. I also open windows every morning and bring in fresh air to keep CO2 low. I don’t know what your budget is, but you can make your own cr boxes for really cheap and then throw a few nice hepa air purifiers on top. I bought all the expensive units used (iqair, Coway, smart air) and saved a ton of money. Just gave them a good cleaning and new filters. Another important thing is to always run your kitchen hood vent when cooking I’ve been keeping my house between 68-72 degrees Fahrenheit so that he sleeps his best and relative humidity between 45-55%. I have a Midea Cube dehumidifier I run when it’s really humid out and humidity in the house gets above 60%. I also vaccum and mop the floors all the time now. We have an old dog that sheds a lot and the floors get covered in hair if I don’t stay on top of it. I kindof rambled but that’s just been what I have been doing and what purifiers I bought to give you some ideas and things to look into.

10 months ago

I just got an Alen Air 25i for my little office and it’s been a really great unit for the last few weeks. Alen sells bundle “whole house” solutions that might work for you. For me, I put a smart air blast in my living room, a iqair GCX in my kitchen, iqair gc in my dining room/front foyer, Alen 25i in the office, Coway Air Mega 300 and 400s in our spare bedrooms, an iq air health pro plus in the master bedroom, and 4 clean air luggable cr boxes spread out throughout the house. Do I have an addiction to buying air purifiers? Yes. Very weird addiction. But all were bought off Facebook marketplace and were pennies on the dollar compared to new. Just had to give them a good wipe down and put in a new filter.

9 months ago

Hey, you and I are in the same boat. I had a baby boy at 31 weeks, now almost 5 month adjusted, and I went down the air quality rabbit hole hard. I want to do whatever I can to keep him healthy and developing normally. He sleeps with us in our room right now. I have a clean air kits luggable xl pc fan cr box and a IQair Health Pro Plus running on setting 2. Both run 24/7. This gives me a lot of air changes per hour and some gas filtration, while staying below 50 decibels. In the rest of the house, I have more luggable xls, smart air blast, iqair gc and GCX, Coway 400 and 300, and an Alen 25i. I think it’s important to get a standalone air quality monitor like the air gradient one or purple air zen. I run the hvac blower fan 24/7 to circulate air through the house. I also open windows every morning and bring in fresh air to keep CO2 low. I don’t know what your budget is, but you can make your own cr boxes for really cheap and then throw a few nice hepa air purifiers on top. I bought all the expensive units used (iqair, Coway, smart air) and saved a ton of money. Just gave them a good cleaning and new filters. Another important thing is to always run your kitchen hood vent when cooking I’ve been keeping my house between 68-72 degrees Fahrenheit so that he sleeps his best and relative humidity between 45-55%. I have a Midea Cube dehumidifier I run when it’s really humid out and humidity in the house gets above 60%. I also vaccum and mop the floors all the time now. We have an old dog that sheds a lot and the floors get covered in hair if I don’t stay on top of it. I kindof rambled but that’s just been what I have been doing and what purifiers I bought to give you some ideas and things to look into.

10 months ago

I just got an Alen Air 25i for my little office and it’s been a really great unit for the last few weeks. Alen sells bundle “whole house” solutions that might work for you. For me, I put a smart air blast in my living room, a iqair GCX in my kitchen, iqair gc in my dining room/front foyer, Alen 25i in the office, Coway Air Mega 300 and 400s in our spare bedrooms, an iq air health pro plus in the master bedroom, and 4 clean air luggable cr boxes spread out throughout the house. Do I have an addiction to buying air purifiers? Yes. Very weird addiction. But all were bought off Facebook marketplace and were pennies on the dollar compared to new. Just had to give them a good wipe down and put in a new filter.

8 months ago

Iqair is a great option. Have one in our bedroom with our 5 month old baby. But can only run it on setting 2 (75 cfm) without going above 50 db. We also have a luggable xl cr box in the bedroom to get more filtration without increasing the sound in the room. We have a Smart Air Blast in the living room and it’s a a quiet beast. Pushes a ton of air, however it’s power hungry. I’m also a fan of the Alens for how they sound and Coway AirMegas.

Reddit Iconsissasassafrastic
11 months ago

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.

7 months ago

AirDoctor doesn't have much activated carbon in their filters... definitely not thick. You're right about IQAir, specifically the GC series purifiers. AllerAir and Airpura purifiers tend to have heavier carbon/sorbent media canisters for the money.

12 months ago

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.

11 months ago

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/).

Reddit IconConsistent-Cold4505
5 months ago

yes there is a lot of hyperbole around them, good marketing, less on air filtration. 1) The UV works to disrupt the dna, but it's not really relevant. The hepa is trapping the spores that are floating around your environment, the UV doesn't need to disrupt them as they haven't colonized yet... and you are replacing your filters regularly if you are half bright because it's mold and you don't want allow them to do so). So the UV does nothing to the air ducts and other places where the mold is actually colonizing... which puts it back to the main issue which is air flow. The unit can only ever filter as much air as it touches, and how fast the filter gets saturated with mold in your environment. It is highly dependent on your place. That said, if I recall the company said the filters last up 2 years and I found that they were fairly useless after 3 months with a 40% efficacy after that time (running on high 24/7). If I were you I'd go with the GC units (they are more expensive IQAIR) but you are already compromised and you don't need the VOC exposure, RADON, etc... and they will mitigate RADON believe it or not I have an Air things unit that tells me my RADON exposure and I see a stark difference with the GC unit. The new ones (and I need to think about upgrading mine) have some pretty good API options too, their software puts together a good summary page and shows you what you are filtering from what I understand.

5 months ago

IQAir Health Pro Plus or MultiGas units are the best you can buy for apartments. The IQAir Perfect 16 (may have newer models now for all these) is the way to go for whole house. They are the defacto best of the best. They are on Airforce 1 for the last 2 decades. In hospitals, clean rooms. They are the best.

5 months ago

that's because you are using a 'feeling', I am using a $5,000 laser particle scanner and have used and tested literally hundreds of them because until I got iqair I was getting pneumonia 3-4 times a year because that's how bad my allergies are. I haven't had pneumonia in almost 10 years now and I continue to test other air purifiers yearly. When I tell you the brand is the best it's because I'm absolutely certain and I have an financial freedom to pursue it in a way a lot of people cannot. Trust me. I'm doing you a huge favor. I can test up to .002 micron size particulates per cubic foot, and I can tell you that IQAir is the only unit that after several years with no filter change achieves 90% efficacy while the 2nd runner up is at 3% after 9 months. What I am not doing is making these statements out of brand loyalty.

5 months ago

yes there is a lot of hyperbole around them, good marketing, less on air filtration. 1) The UV works to disrupt the dna, but it's not really relevant. The hepa is trapping the spores that are floating around your environment, the UV doesn't need to disrupt them as they haven't colonized yet... and you are replacing your filters regularly if you are half bright because it's mold and you don't want allow them to do so). So the UV does nothing to the air ducts and other places where the mold is actually colonizing... which puts it back to the main issue which is air flow. The unit can only ever filter as much air as it touches, and how fast the filter gets saturated with mold in your environment. It is highly dependent on your place. That said, if I recall the company said the filters last up 2 years and I found that they were fairly useless after 3 months with a 40% efficacy after that time (running on high 24/7). If I were you I'd go with the GC units (they are more expensive IQAIR) but you are already compromised and you don't need the VOC exposure, RADON, etc... and they will mitigate RADON believe it or not I have an Air things unit that tells me my RADON exposure and I see a stark difference with the GC unit. The new ones (and I need to think about upgrading mine) have some pretty good API options too, their software puts together a good summary page and shows you what you are filtering from what I understand.

5 months ago

Iqair bar none. Simply the best money can buy. Anything less is honestly wasting your money because your filter will be clogged up in a few weeks and you will have nothing being purified. Seriously, I've tested these things extensively with a laser particle scanner. The cost in filter replacements (contrary to mfg saying replace every xx) drives your total cost of ownership through the roof. The mfg suggest on every major brand allows for a 85% reduction on average in performance because it is still "making a difference". I've tested my iqair machines and after 5 years with no replacements (just cleaning out the pre-filter with my air compressor every few years) is still operating at over 90%. They under promise and over deliver. /end my rant I live with severe allergies that can cause pneumonia so it's a big deal for me. I haven't had it in 10 years because of IQAir. Prior to that it was 2-3 times a year.

4 months ago

IQAir is really the best air purifier, it's about the filter quality and how long the efficacy lasts. Most air filters on the market to very well for about 2 months and then drop to 3-15% efficacy (from 100%). The IQAir is the only one on the market that I've seen stay consistently over 90% for YEARS.

4 months ago

yeah crazy isn't it? Total cost of ownership is much lower. \*tested with laser particle scanner

Reddit IconLDRSHIP24-7
8 months ago

IQ Air multi gas. My doctors offices, pulmonologist, cardiologist, etc . uses them. It really helps me breathe at home.

Reddit IconLunaSloth888
12 months ago

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

Reddit Iconmivuckovic
4 months ago

We’ve had our IQAir Multi Gas for 10 years and love it. We mainly use it during fire season (here in Northern California), and it does an incredible job of filtering smoke and particulates.

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