Maybe you just got a new air purifier, set it up, and turned it on and immediately it produces a funky smell or you may have had yours for some time and it decides to smell like garbage. Whatever your case, a bad-smelling air purifier will leave you wondering why the heck something that's supposed to clean your air is making your air smell horrible.
Without getting into the details, why do air purifiers smell bad? In summary, air purifiers smell bad for various reasons but there are 9 key reasons. The reasons are as follows:
- Off-gassing filters
- Poor room ventilation
- Filters with a new appliance smell
- Ozone production
- Bacteria, yeast, and mold growth on filters and inside the air purifier
- Saturated activated carbon filters
- Off-gassing plastics around the air purifier
- Faulty UV light filter bulbs
- An electrical fault
Smells coming out of your air purifier are certainly annoying and at times can be bad for you and your family’s health, but at times the occurrence is normal and nothing to panic about.
Many times you can actually fix these smells. Given the possible solutions, in this post, I share with you the details on why your air purifier might be smelling and all the fixes you can try for each particular smell and also for some specific air purifier brands and models that are commonly reported to smell.
So, if you have a smelly air purifier, read through this post and I am sure you will have an idea of how to go about resolving your air purifier’s odor problem.
9 Reasons Why Your Air Purifier Could Be Smelling Bad
1. Your Air Purifier Filter Could Be Off-Gassing
Though people who own photocatalytic oxidation (PCO/PECO) air purifiers rarely complain about their air purifiers smelling bad there are some unlucky few who have received units that give off a bad smell.
The range of PCO air purifiers I have seen commonly complained about on various online platforms for producing a bad smell is the Molekule air purifiers. A lot of people say the smell is similar to ozone and some say it's a weird metallic/plasticky smell, while others just say it's an unbearable foul stench.
To rule out that the smell was ozone-related, some people ran experiments on Molekule’s air purifiers and actually found that the odor people complain about is actually from Volatile Organic Compounds being off-gassed from the purifiers air cleaning system.
What apparently causes the off-gassing and subsequent smell is the titanium dioxide and nanoparticle coating on parts of their filtration system. For some people, this smell reduces over time but after many months does not completely go away while for others it does stop.
Now, not all PCO air purifiers come with a nanoparticle coating. Accordingly, based on what I have shown you with the Molekule air purifier, if you have a PCO air purifier and it’s releasing bad smells into your home or workspace, then the reason for this could likely be that your air purifier’s titanium dioxide reactors are off-gassing.
2. Your Air Purifier Does Not Get Enough Ventilation
The next reason why your air purifier could be giving off a bad smell is that it's being kept in an enclosed area with no ventilation. This mainly happens if your air purifier has an activated carbon filter.
In an enclosed area, odors linger around longer and saturate your filters faster. Once your purifier’s filters are saturated with odor molecules, especially your carbon filter when you run it you find it starts to produce similar odors to what was lingering in the enclosed area where you left it.
So if your air purifier does not get adequate ventilation wherever you place it, expect it to absorb and subsequently release the bad smells it's exposed to within your space. These smells range from curry to tobacco, paint, dust, cooking oil, fragrances, and much more.
Also quite common concerning ventilation is for the carbon filters of a new air purifier that you have just taken out of its packaging to release a sweet-smelling scent. The smell is a result of the filter absorbing all the odor coming off the casing and packaging material covering it when it was enclosed.
3. Your Filters Still Have The New Appliance Smell
Quite often with air purifiers, people report a sweet smell or chemical almost plasticky smell. Sometimes such smells can be because you have new filters in your air purifier.
Whether your air purifier is new and you are running it for the first time, or you just replaced its filters with new ones, at times your filters will give off a sweetish scent. A lot of the time this is just a “new appliance smell” that eventually goes away.
4. Your Air Purifier Could Be Producing Ozone
Another common cause of bad or unbearable odors from air purifiers is the production of ozone. Sometimes some people do not realize that the type of air purifier they own produces ozone either as a byproduct or as a main part of its air cleaning system.
If your air purifier has a PCO, Ionic, or PlasmaCluster air cleaning component and it’s giving off a metallic, clean chemical, or chlorine-like smell then it’s highly likely the odor it is producing is ozone. So in this case your air purifier is producing a bad smell cause it is releasing some ozone in your air.
5. Bacteria, Yeast Or Mold Could Be Growing On Your Filters
One of the most annoying smells air purifiers produce has got to be the wet dog smell. This smell is caused by bacteria, yeast, or mold growing on your filters. If these microorganisms have infested your filters they can also cause a fishy like smell.
The wet dog smell also happens with HVACs if bacteria grow on your HVAC filters.
Usually what causes bacteria and other microorganisms to grow on your filters is excessive moisture. This also happens if your filters do not have antibacterial properties or some kind of UV light component to kill microorganisms and prevent them from proliferating.
6. Your Activated Carbon Filter Could Be Saturated
I think I kind of touched on this already under reason number 2 but carbon filters also get saturated over time even though they have ample ventilation so just so you are aware I thought it was useful to point this out.
Over the life of your air purifiers’ carbon filter, it eventually gets so saturated that it starts to release odor molecules it had absorbed from your air. As a result, your air purifier produces all kinds of unwanted smells.
Now, this does not happen for all types of carbon filters. Some activated carbon filters do not produce any bad smell at all and others produce a mild sweet smell during their useful life and stop producing the smell once they are saturated.
That said, most of the time you will smell a sweet smell coming from your air purifier, it's likely going to be coming from your carbon filter because it's over-saturated with odor molecules.
7. Your Air Purifier Has An Off-gassing Plastic Body And Coverings
When your air purifier’s casing is plastic there are so many ways it can release bad smells into your air. Firstly, when plastic is used to manufacture appliances it is known to retain plenty of odors from the various processes used to mold it. These smells then later begin to off-gas slowly and usually, this off-gassing is the plasticky smell you get from your air purifier.
Next, as plastic is sensitive to heat, if your air purifier has a plastic body, when it’s heated up slightly by heat produced by the electricity flowing through its circuits its plastic body can produce chemical fumes. You later smell this as a mild burning plastic smell coming from your air purifier.
For a lot of air purifiers, the plastic smell eventually clears off after several uses. However, if you find the plastic smell is not going away, you might just have a short circuit or some kind of electrical fault that may be slightly melting part of your air purifier’s plastic body, causing your air purifier to release a bad plastic smell every time you try to use it.
8. Your UV Light Filter Is Faulty
The other thing that could be causing a bad plastic smell and even a strong ozone stench from your air purifier is your air purifier’s UV light. If you have an air purifier with a UV light filter and your UV light gets faulty, you may start to get a strong burning plastic smell from your air purifier whenever you use it.
9. Your Air Purifier Has An Electrical Fault
Besides the melting plastic smell an electrical fault can cause, an electrical fault in either an air purifier with a metal or plastic body can cause fishy or urine like metallic smells to come out of your air purifier whenever you put it to use.
So these are the 9 common reasons why your air purifier could smell bad. Next, I am going to discuss the steps you can take to fix a smelly air purifier. Also, to summarize and contextualize the 9 reasons and how you can fix these smells, I am going to present these reasons in a table based on the type of bad smell you may get from your air purifier.
Steps You Can Take To Fix Bad Smells From Your Air Purifier
9 General Steps To Get Rid Of Bad Smells From Your Air Purifier
1. Provide Enough Ventilation Wherever You Place Your Air Purifier
As bad smells from your air purifier may be caused by your purifier being in a place where it's enclosed and not getting enough ventilation, it is only logical that you have to either improve ventilation wherever you place your air purifier or move your air purifier to a ventilated area.
By providing adequate ventilation for your air purifier, you prevent its filters from getting saturated with odors, and your air purifier subsequently redistributing bad odors from its saturated filters back into your air.
The other thing you also want to do to avoid bad smells from your air purifier due to saturated filters is to implement additional measures in your home or workspace to get rid of bad smells.
You can place activated carbon bags around your rooms, install exhaust fans, open windows, install a cooker hood, or even place air movers around your facility or home to minimize lingering odors. In this way, your air purifier filters are less likely to get saturated with odor molecules and release bad odors back into your air.
2. Air Out Your Air Purifier
For air purifiers that are producing the “new appliance” smell or a plastic smell, this smell sometimes dissipates over time. However, to speed up the process of getting rid of this type of smell, you can try to deliberately air out your air purifier.
Expose your air purifier to fresh air and try running it with windows open for a while. Open up your air purifier when you are not using it and disassemble your filters and place the entire disassembled unit outdoors to catch some air.
Do this daily for a week. If there is no change, then consider getting a refund or a replacement unit if you are sure the unit you got is smelling cause it's faulty.
3. Remove All Plastic Packaging And Wrapping Before Using Your Air Purifier
Sometimes it so happens when people use their air purifier for the first time they do not take off all the plastic wrapping around the air purifier. Wrapping around your new air purifier may not just be on its exterior but also around its interior and filters.
So, before you run your air purifier for the first time or if you have run it for the first time and it is producing plasticky smells, double-check every single part of your air purifier for wrapping and remove any wrapping you may have missed and this should fix your bad smell problem.
4. Take Your Air Purifier To An Electrician For Repairs
When you get a burning, metallic, fishy, or urine smell from your air purifier, most times this will be due to an electrical fault. Unless you are an electrical technician yourself there is not much you can do about this apart from taking the appliance back under warranty or if your warranty has lapsed you can try to take it to an appliance repair shop for fixing.
5. Use Sodium Chlorite And Chlorine Dioxide Solution To Clean Your Air Purifier
For air purifiers producing a wet dog smell or dead fishy smell, sodium chlorite apparently helps to get rid of such odors whether they are coming from your air purifier’s filters or its body. Chlorine dioxide and sodium chlorite work for such odors as they are active ingredients in numerous products used in the control of bacteria, fungi, and algal slimes.
As wet dog smell and any other such funny smell from your air purifier are caused by bacterial microorganisms, sodium chlorite is a very effective approach to deal with such smells from your air purifier as it kills the bacteria causing the smell rather than just masking the odor.
To use sodium chlorite to get rid of bad odor from your air purifier caused by bacteria, yeast, or similar microorganisms, pour some solution in a wide dish. Pour enough for the solution to sit just over the surface of the dish.
The solution level in the dish should be less than 1 inch and your dish should be wide enough to place your filter over it. Next place your filter over the solution using the edges of the dish or a small plastic block in the middle of the dish.
Make sure your filter does not touch the solution. Once you have placed the filter above the solution, enclose the filter over the dish with a plastic cover. Make the covering as airtight as possible and let the filter sit like this over the sodium chlorite solution for 20 mins.
When you are done, the smell on your filter should be gone. You can repeat this process for your entire air purifier but make sure to do it separately from your filters to make the process easier. Also with your air purifier, you may need to use a large bucket instead of a dish.
Be sure to handle the sodium chlorite with care as it is a dangerous chemical. Just to make sure I get rid of as much surface bacteria on my air purifier as possible, I would also clean my air purifier’s body as best as I can before exposing it to the sodium chlorite vapor.
6. Replace Your Filters And Maintain Your Air Purifier
When your air purifier smells, sometimes the solution can be as simple as replacing some of its components or cleaning it. Some air purifiers have washable filters and prefilters. Clean these regularly and wipe down the interior of your air purifier with a non-corrosive cleaning chemical.
If you have filters that can be replaced and you believe they could be the source of your air purifier’s bad odor, try replacing them even though it’s not time to replace them yet. You may find that just replacing filters and maintaining your air purifier may get rid of the smell.
7. Turn Off Ozone Producing Parts Of Your Air Purifier
Some air purifiers come with a combination of air cleaning technologies. Your air purifier may have an ozone-producing component like an ionizer, ozone generator, or plasma cluster air-cleaning feature which causes a bleach or chlorine-like smell.
Many times such air purifiers allow you to turn off these components. If your air purifier is producing ozone like smells, check if it has ozone producing components and a way to turn these off. If it does, your solution to get rid of the ozone like smell is simply turning off these features.
8. Reduce The Moisture In Your Air
Moisture and humidity are key ingredients needed for odor-causing bacteria to thrive. Accordingly, running your air purifier in a humid place can lead to moisture build-up in its interior and on your filters, and subsequently odor-causing bacteria continuously building their colonies in the interior of your air purifier.
Given this, to prevent your air purifier from producing bad smells due to bacteria that thrive under high humidity levels, you will need to get rid of moisture wherever you operate your air purifier and by far the most effective way to do this is by using a dehumidifier.
9. Replace Or Return Your Air Purifier Or Filters
Finally, if you cannot pinpoint why your air purifier is smelling bad you may just have to replace your unit. In the case where it worked fine previously, the new filters you get may just be the culprit and you could resolve the issue by hunting for better quality or genuine filters.
However, if you have tried everything and your air purifier continues to smell, send it back for a refund if you still qualify for one and get a better air purifier that does not have smell problems. You may also try a replacement unit but ultimately if the problem persists, get a refund if you can, as there are plenty of other options out there that do not have odor issues.
If you are way past your refund period and you cannot pinpoint why your air purifier persistently smells bad, you might be better off just getting a new air purifier. Should you decide to get a new air purifier, try to get a hybrid one that includes a UV light or antibacterial filters to avoid smells like wet dog smells.
I personally would also aim for air purifiers made of high-quality plastics or better yet, air purifiers with a metal body, to avoid off-gassing plastic smells from these appliances. So these are the general steps you can take to resolve some bad air purifier smells. Next up, I summarize the various smells and how to resolve them in a table for your quick reference.
How To Fix Bad Air Purifier Smells By Type Of Bad Smell
As most of the time when your air purifier produces a bad smell, you ask why it smells by initially describing the type of bad smell, my table summary below allows you to quickly pinpoint why your air purifier smells based on the type of bad odor you smelled it producing. In the table, I also summarize what steps you can take to get rid of the given type of smell.
Summary Of Steps To Get Rid Of Air Purifier Smells
Air Purifier Smell Query | Reason For Your Air Purifier Smell | Solution |
|---|---|---|
Why Does My Air Purifier Smell Like its Burning | An electrical fault or faulty UV light | Change the UV light bulb, return the air purifier if it’s under warranty, or have an electrician fix the fault |
Why Does My Air Purifier Smell Like Chlorine | Ozone production or your filters are saturated with the odor due to poor ventilation | Turn off the feature of your air purifier that produces ozone, or switch the air purifier to one that does not produce ozone. Place your air purifier in a well-ventilated room |
Why Does My Air Purifier Smell Like Curry | An air purifier may be placed in a poorly ventilated place in a storeroom or kitchen | Use a cooker hood exhaust fan when cooking. Ensure the air purifier is getting enough ventilation. Change saturated filters |
Why Does My Air Purifier Smell Like Ozone | Air purifier has an ozone-producing component you are not aware of | Turn off the ozone producing component of your air purifier if possible. If not, look for another type of air purifier |
Why Does My Air Purifier Smell Like A Wet Dog | Odor causing bacteria on your filters and the interior surfaces of your air purifier | Wash your air purifier’s body and clean both the filter and body by exposing them to sodium chlorite. Alternatively, replace your filters |
Why Does My Air Purifier Smell Like Vinegar | Odor causing bacteria on your filters and the interior surfaces of your air purifier | Wash your air purifier’s body and clean both the filter and body by exposing them to sodium chlorite. Alternatively, replace your filters |
Why Does My Air Purifier Smell Like Maple Syrup | Saturated activated carbon filter or poor ventilation around your air purifier | Replace your activated carbon filter and place your air purifier in a well-ventilated place |
Why Does My Air Purifier Smell Like Fish | Odor causing bacteria on your filters and the interior surfaces of your air purifier or air purifier in a poorly ventilated kitchen or an electrical fault | Clean your air purifier and filters with sodium chlorite. Replace your activated carbon filter and place your air purifier in a well-ventilated place. If this is due to an electrical fault, take your air purifier to an appliance repair shop |
Why Does My Air Purifier Smell Like Smoke | An electrical fault, or filter saturated by smoke smell due to poor ventilation | Replace your filters and place your air purifier in a well-ventilated place. If this is due to an electrical fault, take your air purifier to an appliance repair shop |
Why Does My Air Purifier Smell Stale | Air purifier placed in a poorly ventilated area | Replace your air purifier filters and place your air purifier in a well-ventilated place or increase ventilation where you are operating your purifier |
Why Does My Air Purifier Smell Sweet | Saturated activated carbon filter or poor ventilation around your air purifier | Replace your activated carbon filter and place your air purifier in a well-ventilated place. |
Why Does My Air Purifier Smell Like Plastic | Off-gassing from air purifier body or an electrical fault | Air out your air purifier and filters by exposing it to the air daily for 1 week when not in use. If smell is due to an electrical fault, take the purifier to an appliance repairs shop |
Why Does My Air Purifier Smell Like Paint | Air purifier placed in a poorly ventilated area | Replace your activated carbon filter and place your air purifier in a well-ventilated place. |
Why Does My Air Purifier Smell Like Perfume | Air purifier placed in a poorly ventilated area | Replace your activated carbon filter and place your air purifier in a well-ventilated place. |
Why Does My Air Purifier Smell Like Yeast | Odor causing bacteria on your filters and the interior surfaces of your air purifier | Wash your air purifier’s body and clean both the filter and body by exposing them to sodium chlorite. Alternatively, replace your filters |
Why Does My Air Purifier Smell Like Bleach | Ozone production or your filters are saturated with the odor due to poor ventilation | Turn off the feature of your air purifier that produces ozone, or switch the air purifier to one that does not produce ozone. Place your air purifier in a well-ventilated room |
How To Fix Bad Smells From Specific Air Purifier Models
Now that you have an idea of why air purifiers smell bad and how to generally get rid of these bad smells, we can take a look at how to fix bad smells produced by specific air purifier brands and models. I summarize the brand-specific solutions below but do note for some air purifiers no one has found a way to fix their bad smells.
Air Purifier Smell Solutions By Specific Appliance Model
Air Purifier Model Smell Complaint | Reason And Type Of Bad Smell It Is Producing | Solution For Bad Smell |
|---|---|---|
Austin Air air purifier smells | Produces sweet or sour smell, or an odor of ammonia or vinegar from the filters | Austin air recommends you simply replace your filters. If the smell is from a HEPA filter you can also try treating the filter with sodium chlorite as I have pointed out previously for odors caused by bacteria |
Molekule air purifier smells | Produces plastic smell and new appliance smell | Air out your air purifier and allow the smell to fade over a week. However, for some people, the smell never goes away and the only solution is to try a different air purifier |
Philips AC3256 air purifier smells | Produces plastic smell, produces dusty odor and sometimes produces burnt smell and other unpleasant smells | Air out your air purifier and its filters. For burnt smells, get your air purifier checked for electrical faults. Other smells may be caused by saturated filters so you may need to replace your filters and ensure you place your purifier where it’s getting enough ventilation |
Samsung air purifier smells | Air purifier produces smells similar to odors that were lingering around its surroundings | Turn off the ozone producing component of your air purifier if possible. If not, look for another type of air purifier |
Honeywell air purifier smells | Producing rubber and oil smell caused by filters with oil residue and black powder and silicone sealant and wet dog/urine smell | Wash your air purifier’s body and clean both the filter and body by exposing them to sodium chlorite. Alternatively, replace your filters |
Winix air purifier smells | Producing a strong plastic smell. | Wash your air purifier’s body and clean both the filter and body by exposing them to sodium chlorite. Alternatively, replace your filters |
Levoit LV-H132 air purifier smells | Producing a burning smell. Likely due to an electrical fault. Units do not normally produce a burning smell | If you catch this problem early within warranty, you can get a replacement unit from your supplier. Otherwise, you have to take it to an appliance repair shop |
Alen Breathe Smart air purifier smells | Producing plastic and glue-like odor. The odor is caused by the pre-filter | Problem existed for a few faulty units and has now been corrected by the manufacturer |
IQAir air purifier smells | Producing, sweet smell, plastic smell, or chemical smell from filters. This is due to potassium permanganate filters which develop sweet odor in as little as 60 days if indoor air is heavy with Acetaldehyde or Formaldehyde | The solution here is to replace IQAir’s activated carbon filter which is filled with potassium permanganate. You can get a free filter replacement if your air purifier arrives with a sweet-smelling filter. Sometimes some suppliers package this filter badly and it comes with a smelling sweet, don’t settle until you get a filter that does not smell sweet. |
Dyson air purifier smells | Producing a sweet yeasty smell likely due to glue on the filters | Based on user reviews I found the best way to fix the Dyson smell is to get a custom-made filter replacement from another non-brand air filter supplier. Unfortunately, so far Dyson’s filters are still made with the glue that makes your air purifier smell weird. |
Top 3 Air Purifiers That Don't Smell Bad
If you are frustrated by the bad smells from your air purifier, let me reassure you with the video below that you are not alone in this problem. The video shows someone's grief with bad smells from a Dyson air purifier. This is such a common problem but do not write off air purifiers just yet.
If you have tried everything with your air purifier and the smell does not go away, the final solution is to try an air purifier from a completely different manufacturer. Fortunately there are a couple of options when it comes to air purifiers that will not off-gas and produce smells that leave your home smelling funky.
Of the numerous options, there are 3 effective air purifiers that I stand by for your home or office that I know for sure will not produce or release bad smells into your air. They include the
- Enviroklenz Mobile Air System,
- Medify Air MA-40-W
- Jade Surgically Clean Air
Lets briefly look at each of them.
1. Enviroklenz Mobile Air System
The Enviroklenz air purifier can clean air in rooms of up to 100 sq. ft. 
It only filters air particles down to 0.3 microns in size but still more it outperforms many top ranking air purifiers that are claimed to filter smaller particulates. As for producing bad smells, this air purifier has a metal body and so you definitely won't face any plastic smells.
Furthermore it is tailored towards people with Multiple Chemical Sensitivities. Simply put, this means expect no bad smells and to date I am yet to hear any complaints. This air purifier is by far my first choice when it comes to air purifiers that don't leave a bad smell behind. You can check out the Enviroklenz air purifier here.
2. Medify Air MA-40-W
If you are looking for an affordable air purifier that won't give you off-gassing problems, look no further than the Medify Air MAX-40-W V2.0. This air purifier comes with an H13 True HEPA filter, that can remove 99.9% of pollutants down to 0.1 microns. The air purifier can clean rooms of up to 840 square feet in just 30 minutes with a CADR of 330. It is nice, compact and easy to move around. Check out the Medify MA-40 here on Amazon.
3. Jade Surgically Clean Air
At about US$2500 the Jade SCA 5000 C is quite a pricey air purifier. I think its expensive but if you want a premium range purifier that works and does not leave any smell in your home or office, this is your best bet. The Jade SCA5000C air purifier is designed for medical grade nanoparticle air filtration and can deliver clean air into your room at an airflow rate of 406 cubic feet per minute. You can learn more about the JADE SCA air purifier here.
These are my top 3 air purifier to turn to if you need an air purifier that does not off-gas and produce any funny odors. For more, you can click here to see a list of all the air purifiers I highly recommend and some other options that are unlikely to give off bad odors.
To conclude, let me say that sometimes a bad smell coming from your air purifier may not be a bad thing. This is especially true if the bad smell occurs after at least 1 month of using your air purifier.
The bad smell may be an indication of the amount of filth in your air that your air purifier has gotten rid of. If that is the case, then your air purifier simply needs to be regularly maintained and it does not have an actual problem.
Yes, bad smells may indicate your air purifier is faulty but that is not always the case. Make sure to investigate, test, and do your research before drawing your conclusion and throwing out your air purifier.
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Comments
What would have been much more useful would be for you to list air purifiers that have not been associated with smell, or to state that none are known.
The pop ups at your website are so annoying that I would not buy from any company that advertises at your website.
Hello Jones,
I greatly appreciate your feedback. By popups do you mean the ads in the middle of text or actual new windows popping up on your screen? You should not be getting any windows popping up, only ads on the sides and in some parts of the text of the article. If you are getting windows popping up please confirm as this is a problem and something is certainly not right.
Also, please do not feel obliged to buy through any ads on our site. If you do, you help us pay our bills and keep sharing information here and we greatly appreciate it.
As for recommendations on which air purifiers do not smell, you are very right. I should have put that here. There are some good air purifiers that do not smell. Very great suggestion and I am updating the article immediately. thanks for pointing that out.
Hi there —
I was quite happy to find this post. I have been quite aware of the issue of odors emitted by Aipurifiers by various suppliers and/or HEPA and odor-reduction claims not met.. Most of the issues covered here do not apply in my case. The issue that I face most frequently is that the materials used to make pleated HEPA media have odor when new, and some media odor never seems to dissipate.
Most low-cost HEPA filters that are used in consumer air purifiers (including quite costly purifiers, like IQAir) use hot-melt glue to hold the pleats to the frame and to keep the pleats separated. In addition, they use silicone hydrophobic coating on the fiberglass media to repel humidity (virgin glass is hydrophilic). Both materials are potential sources of odors, particularly the hydrophobic coating (since the media are is quite large, by definition). Some odors dissipate after a few days of use, some never dissipate. For example, newest batches of IQAIr hyper-hepas are non-useable (my case) and I had to return them for a refund. The company never commented on the issue (old batches from 10-15 years ago were fine).
To solve the issue, I ordered professional grade HEPA filters from several manufacturers (OZCON and CAMFILL) and tested them for odors. Then, once a good batch was identified, I ordered several. Thankfully, IQAir units are modular, and this allows for installing of OEM filters roughly simliar in size (305x305mm footprtint). Gaps can be sealed with Aluminium tape or KAPTON tape (my approach). If the HEPA is to tall, 250mm spigots are attached via the same tape, w/o any reduction in particle-count performance or air resistance.
Generally, high-temperature rated HEPA filters made using stainless steel, VITON gaskets, and Aluminium (metal) separators off-gas less than cheap consumer HEPAS. Silicone gaskets off-gas, but the odor can be dramatically reduced by baking the silicone part at 120C for 5 hrs.
PTFE is another inherently odor-free membrane material which is made using ultrasound welding (no glue at all). However, I failed to source single-quantities of these exotic filters (one company offered a custom sized one for 4K a piece).
Interestingly, 3M Filtretes (the highest-rated MERV ones, 1″ thick) are odor free, relatively affordable, and easy to source. When two 1″ thick Filtretes are stacked in series (one after another) I get the same performance, in terms of particle counts than a $250 IQAir HyperHepa. This is a quick fix solution as they probably do not last as long, and pressure drops can be significant, so do at your own risk
Yet another issue is that carbon media which used to eliminated smell can smell like burning wood (charcoal manufacturing?); I had this issue recently with an Aliexpress-sourced in-duct filter (used in hydroponics). I do not have much experience with sourcing activated charcoal; it would be interesting to know which suppliers of charcoal make inherently low-odor filters and can be trusted. Particle-wise they are fine. Some of IQAir “odor-reducing” media just does not work at all, despite its high cost the odors go right through. This is why I am looking for alternatives.
“Yet another issue is that carbon media which used to eliminated smell can smell like burning wood (charcoal manufacturing) “
This is something I can’t understand. Why would anyone replace ‘odors’ with a burning wood odor? I Just picked up a levoit 400s and all I could smell was this charcoal like burning wood odor. I’d rather just not have the odor removing functions if that smell is what I have to look forward too,