I have lived with dogs, cats, rabbits, fish and tortoises, as family pets over the last 55 years, so I know the territory. I also have asthma and I am a physician and so appreciate the human health issues. Here are my recommendations.
On the whole the best air purifier for pets taking your pets needs into account is a Coway 400S. This is because it has excellent particle filtration and a good carbon filter for you and is very quiet for your pet’s sensitive high frequency hearing.
Let me explain-
The Aspects of Pets That We Humans Need an Air Purifier to Deal With
As a general rule air purifiers will only help very slightly with pet hairs. The reason is that pet hairs are heavy enough to fall to the ground before the air can carry them to wherever in the room the air purifier is. So although air purifiers can remove pet hair from the air the pet will have to be fairly close to the air purifier for the hair to be carried into it. Still a few hairs will enter the intake of the air purifier.
These are fragments of your pet’s skin that are so small that they remain suspended in the air. You can then breathe them in and they will settle in your lungs. Here depending on your immune system they may cause an allergic reaction and you may notice that you wheeze. Fortunately, they are not small enough to get very deep into your lungs and enter your bloodstream.
Pet smells can come from their skin, fur, cat litter or accidents in the form of urine or feces. The smell in all of these is caused by volatile organic compounds.
An air purifier with a carbon filter is capable of removing chemicals including those that are responsible for a pet smell. So air purifiers really do help with pet smells. In fact this is one of the main reasons for getting an air purifier when you have pets.
So one of our main criteria for the best air purifier for pets is going to be a good carbon filter.
The Aspects of the Air Purifier That Pets Need
A dog’s sense of hearing is very much more sensitive than our hearing, they can hear sounds that we cannot. We can hear sounds up to a frequency of 20,000Hz whereas they can hear sounds up to a frequency of 65,000Hz. This also goes for most other pets-
|Highest Frequency Audible (Hz)|
So pets need us to choose the quietest possible air purifier that will still adequately purify the air. They also need one that will produce as little high frequency, high pitched, noise as possible.
Particle Reduction-not the deciding factor for choosing an air purifier for pets
Basically an air purifier has a fan which sucks in air and then pushes it through the filter where the airborne particles are then trapped. The trapped particles are permanently removed from the air so improving indoor air quality. So the most important features of an air purifier are the quality of the filter and the amount of air that the fan is pushing through it every minute.
Virtually all pre-filters will stop pet hair so although some air purifier manufacturer’s point to a special pet hair pre-filter it is not really essential. There is in any case no chance of pet hairs getting through a HEPA filter.
Airborne particle removing filter
1) All true HEPA Filters-easily remove pet associated particles. So filter quality does not decide which air purifier air purifier is best for pets
The most damaging aspect of poor quality air on health is usually due to the effect of particles. So a crucial feature of any air purifier is the air filter that removes airborne particles as this determines the highest purification that the air purifier can achieve. HEPA filtration is extremely efficient and now effectively the minimum standard for a filter. Therefore, it is important to have a true HEPA filter-this will effectively remove almost all airborne particles. Beware of “HEPA like”, “HEPA style” “99% HEPA”… terms describing the filter like this means it is not a true HEPA filter. You may think it means that the manufacturer is not being straightforward with their potential consumers.
The HEPA specification is based on the ability to remove fine particles 0.1um-10um. The standard specifies that the filter must remove 99.97% of particles of 0.3um in diameter. So as animal dander is 2.5-10um in diameter a HEPA filter will easily remove them. It will also remove pet allergens and airborne bacteria.
So ultrafine airborne particles which are less than 0.1um and so not explicitly covered in the HEPA specification but they are also major health concern. These particles have been found in the bloodstreams of humans and are thought to be very important in the damage to human health from pollution, as outlined in this article. Some air purifier manufacturers are now specifying the range of ultrafine particles that their HEPA filter will remove. My top pick, the Coway 400S is certified to remove 99.95% ultrafine particles down to a diameter of 0.01um.
This is a filter specification that separates the Coway 400S from all others on the market except the iQair HealthPro Plus.
So we have seen that a HEPA air purifier is essential but does not decide which air cleaner to choose amongst the 100 or more models with a HEPA filter.
2) Airflow-there are no special requirements for pets. So airflow is not the deciding factor
The usual EPA guidelines apply in that there should be at least 5 air changes per hour to reduce particle count by 80%. If the air is optimal for you then your pet will also enjoy better health, cats for instance are prone to respiratory problems.
The clean air delivery rate (CADR) that you need your air purifier to supply to meet this can be found from the following table-
If you do not have 8 foot ceilings then you will need to use the calculator on this page.
Now you have the CADR that you need, but this needs to be the CADR at a noise that you can tolerate. It is unlikely that you will be able to tolerate the noise of an air purifier on its maximum setting, it will usually be so loud that it becomes stressful. So you will need the noise data for lower airflows to check that there is one setting that produces the CADR that you need without being too loud. Please see this article for further details.
Smell Reduction-this is the deciding factor for us and a factor for our pets
Although it is great to have pets in the home, they can make the home smell and give the home a cat or dog smell. More extreme is the smell of excrement, this is mainly cat litter and dogs during the initial house training. So from our point of view having an air purifier with the capacity to remove the smells is essential for a pet air purifier.
As our pets sense of smell is so much better than ours, it is probably nice for them for some of the odor to be removed so that it does not dominate their sense of smell. A dog has a sense of smell that is 10,000-100,000 times better than ours depending on the breed.
a) Activated Carbon Filter
The chemicals that cause smells can be removed by an activated carbon filter. The best carbon filter in a HEPA air purifier with a good airflow at a noise of less than 50db, is the iQair Multigas, which is oulined below.
Below is a picture of a large carbon filter, this is the 2nd largest on the market in a HEPA air purifier, it has 5.5lb of activated carbon in it. Most other air purifiers have less than 1/10-1/1/00th of the activated carbon.
One company advertises a patented technology concerning their carbon filter for pets, they give this a special catchy name. To demonstrate how some air purifier claims are difficult to assess, here are the problems with that claim-
- They make no claims about how effective it is just that it is more effective and therefore worth a higher price than the standard filter. It may make the filter 1% more effective for all we know. The fact that they do not widely advertise it suggests that it is on the low end of increased effectiveness.
- They advertise this as a particular feature of their air purifier for pets-if it is so effective why not put it in all their air purifiers?
- The structure of their filter and the carbon granules means that 80% of the air going through the filter will not come into contact with the carbon at all! So there is no chance of it working on that air. Why not just put more carbon in the filter so that at least 95% of the air comes into contact with it? This would cost a few cents more but may be much more effective than the patented technology.
- It is great that they are trying to get the most out of the filter, however the filter does not have a lot of activated carbon in it probably around 0.3lb.
This is typical of marketing in air purifiers you need to read between the lines.
As a general rule carbon filters in air purifiers will very much reduce pet smell provided the air flow is high enough but will not be able to eliminate it entirely. To help in eliminating the smell, vacuum regularly, clean carpets and floors, and have covers for furniture which can be washed.
Filter replacement will mean that the particles on the HEPA filter and the volatile organic compounds on the activated carbon filter will be permanently removed from the home. The replacement filters will begin removing both particles and the cycle will begin again leading to continuous permanent removal of pet fur, pet allergens and pet odor from the home.
This air filtration will remove airborne contaminants and give anyone with a pet allergy the best chance of tolerating their pets, although they could as well as the air purifier try a PECO device to destroy some of the remaining pet allergens.
Photo Electrochemical Oxidation (PECO) as present in the Molekule is an alternative way of dealing with chemicals by directly destroying them. This may be a useful additional technology if necessary once you have an air purifier with a HEPA filter and activated carbon filter but it cannot be used as the only air purifier as it is not good at removing particles from the air.
Noise-this is a deciding factor to be kind to our pets
As explained above pets have much more sensitive hearing than we do. This is especially so as the frequencies exceed 8000Hz, they can also hear much much higher pitched sounds than we can.
So from our pets point of view we need-
- A Large Air Purifier-just as cellos have a lower tone than violins, larger air purifiers tend to have a lower tone than small air purifiers. So as our pets tend to have very sensitive high frequency hearing it seems kinder to them to have a larger air purifier to minimise the high frequencies as much as possible.
- A Quiet Air Purifier-to prevent our pets being stressed by what they hear as a constant loud noise we would be best getting the quietest air purifier possible.
The Coway 400S has both these attributes and thus is the pets choice of air purifier.
Controls-if you have a very intelligent, inquisitive pet this could be the deciding factor
If your pet is likely to play with the air purifier controls then a pet lock may be helpful. However as the pet lock is usually one of the controls they may simply learn to turn the lock off!
To illustrate the time course of particle reduction by an air purifier, I performed an experiment*. Here are the results-
So you can see with the air purifier on its maximum setting and providing 9.4 air changes per hour the reduction in particle count only mildly surpassed the EPAs minimum target for adequate particle reduction. This shows that it is best to be careful in buying an air purifier and to check that it really will deliver a minimum of 5 air changes per hour for your room on its second to highest setting. In general you are unlikely to be able to tolerate an air purifier on its maximum setting for long as it is too noisy.
So the air will still be polluted for 30 minutes after the air purifier has come on. So if you do not have a smart air purifier that will come on 30 minutes before you step into the room you are either going to be breathing in more polluted air than you need or you will have to leave the room and come back 30 minutes later.
For some air purifiers you can convert a dumb air purifier into a smart one by buying a purifier with a timer or plugging it in to a programable smart plug. This is a good solution as it allows different schedules on different days of the week. You may want a very different schedule during the working week from that at the weekend. The most expensive air purifiers can be run in this way.
Unfortunately, many air purifiers when the power to them comes on again they sit there doing nothing until you press the power button which means that you cannot control them with a smart plug. So you will have to go into the room 30-45 minutes before you want to be in it to switch on the air purifier. These are usually the cheaper air purifiers.
WIFI connected air purifiers can be controlled by smartphone Apps, Alexa or Google Home.
I only recommend either WI-FI controlled air purifiers or those that manufacturer’s have specified come on at the same airflow that they were last operating at and so can be operated with a smart plug.
Control Lock So Pets Cannot Alter Settings
Some manufacturer’s have a setting to lock the air purifier. However, I would not put it past a pet to learn to unlock it!
One manufacturer has exactly the same lock mechanism on their “pet” air purifier, but the logo for the switch is a paw print rather than a lock!
All Other Air Purification Technologies Have Problems
HEPA air purification with an activated carbon filter and a fan to push air through the filters is the standard method of air purification. There are other techniques but they have problems compared to this standard-
- PECO eg the Molekule-not effective enough at reducing particles see Wirecutter YouTube video above.
- UV light-ineffective at dealing with some microorganisms (please see this article), potential for eye damage and ozone production depending on technology used. This technology does not remove particles.
- Ionising air purifiers give particles an electric charge which makes them stick to things. They can reduce particles count in the air but increase the depositing of particles in your lungs. This technology does not deal with chemicals. Further details of how ionizing air purifiers work can be found here.
- PCO-photocatalytic oxidation-uses UV light and titanium oxide to change particles. It does not remove airborne particles such as mold spores, allergen, house dust mite, pet dander, house dust particles, or cigarette smoke particles. It can produce formaldehyde which is carcinogenic.
- Ozone generators-damaging for health in any case and like PCO and UV light do not remove particles.
So air purifiers based on these alone would not be the best air purifier for pets.
Best Air Purifier For Pets
Coway 400S (Nice and quiet for pets-best for pets with humans)
My top pick for pets because of its superb filter and high airflow a the lowest possible noise levels for the airflow. This may be the best compromise giving humans excellent particle filtration, good pet odor reduction and pets a quiet environment.
|HEPA filter||HEPA specified to remove 99.8% of ultrafine particles down to a size of 0.01um|
|Carbon filter amount of carbon (lb)||1.5 lb so more than most other air purifiers|
|Filter Change HEPA (Particles)||12 months|
|Filter Change Carbon (Chemicals)||12 months|
|CADR at =<50db (CADR on Maximum)||293 cfm|
|Maximum Room Size (Noise less than 50db*)||450 sq ft|
|Maximum Room Size (On noisiest setting)||640 sq ft|
|Smart Control||Yes phone app|
|Dimensions “H x “W x D”||22.8 x 14.8 x 14.8|
|Annual Running Cost Electricity ($)||$40|
|Annual Running Cost Filters ($)||$120|
|Total Annual Running Cost ($)||$160|
All the above are approximate and assume running the air purifier for 12 hours per day on the highest setting that keeps the noise below the level specified in db in the table. This is less than or equal to 50db in normal daytime use and 35db for bedrooms.
*Most people will not wish to have the air purifier on a setting louder than about 35db for sleeping in a bedroom-you may wish to have a quieter setting than 35db this is just a ballpark estimate for most people. On the other hand, if your room layout allows you to be much further than 6 feet from the air purifier you may find the noise this machine makes at top speed is alright. The calculations for room size assume that you have 8 foot ceilings and 5 air changes per hour.
Never run an air purifier on auto mode using the inbuilt sensor. These cannot detect ultrafine particles which are damaging to human health, please see this article- How to test the air quality in your home.
iQair Multigas (supreme chemical filter specification and supreme particle filter-best for humans with pets but not cheap)
This is a superb air purifier but depending on room size it could be a little noisy for pets. It is the best air purifier that money can buy for reducing pet odors. Noiser than the Coway for pets with their sensitive hearing.
|HEPA filter||HEPA specified to remove 99.8% of ultrafine particles down to a size of 0.003um|
|Carbon filter amount of carbon (lb)||12 lb so so 100x more than some other air purifiers|
|Filter Change HEPA (Particles)||12 months|
|Filter Change Carbon (Chemicals)||29 months|
|CADR at =<50db (CADR on Maximum)||170 cfm|
|Maximum Room Size (Noise less than 50db*)||262 sq ft|
|Maximum Room Size (On noisiest setting)||462 sq ft|
|Smart Control||Yes smart plug|
|Dimensions “H x “W x D”||28x 15 x 16|
|Annual Running Cost Electricity ($)||$45|
|Annual Running Cost Filters ($)||$285|
|Total Annual Running Cost ($)||$330|
For an explanation of the basis of the calculations please see grey block above.
IQair HealthPro Plus
A slight step down from the iQair Multigas in terms of chemical/small removal but cheaper to buy and run with excellent ultrafine particle reduction. Still louder than the Coway for 400S for pets. I have written an article about it here.
Cheapest Air Purifier For Pets-$80
This is the cheapest option. Particle filtration is good Pet odor reduction average so if you have a problem with pet odor you would be better choosing one of the other choices. Also noise is average for pets rather than quiet.
This air purifier has the highest airflow per dollar of any air purifier on the market from a well known manufacturer, approximately double that of most other air purifiers.
|HEPA filter||HEPA 13 filter|
|Carbon filter amount of carbon||Small amount of carbon incorporated into main filter 0.1 lb|
|Filter Change HEPA (Particles)||7 months|
|Filter Change Carbon (Chemicals)||7 months|
|CADR at =<50db (CADR on Maximum)||118 cfm (118 cfm)|
|Maximum Room Size (Noise less than 50db*)||183 sq ft|
|Maximum Room Size (On noisiest setting)||183 sq ft|
|Smart Control||Smart Phone App/Alexa/Google Home|
|Dimensions “H x “W x D”||12.6 x 8.1 x 8.1inches|
|Annual Running Cost Electricity||$24|
|Annual Running Cost Filters||$45|
|Total Annual Running Cost||$70|
For an explanation of the basis of the calculations please see grey block above.
What Are the Best Air Purifiers for Pets for Larger Rooms?
The Coway 400S is the best air purifier for pets for larger rooms. It is a superb large room air purifier because of its huge airflow at relatively low noise. Please see this article.
Regarding small rooms. The Coway 400S is the best air purifier for pets for smaller rooms. Because of its high airflow it could be operated on one of its lowest flow settings and this would be so quiet that it should not stress your pet.
Are Air Purifiers Good for Pets?
There is incontrovertible evidence that fine particulate air pollution harm human health and there is good evidence that air purifiers improve human health. Those pets that are mammals like us will very likely have a similar improvement in health. The data behind this for humans is clearly outlined in this article, which ideally everyone would read once as it will open your eyes to a health problem that you never realized was so important.
Are Air Purifiers Safe for Pets?
As a general rule air purifiers are not only safe for pets but also likely to improve their health. In view of their sensitive hearing care needs to be taken to buy the quietest air purifier that will be adequate for your room.
Do Air Purifiers Help With Pet Allergies?
On the whole air purifiers will help with pet allergies by reducing the amount of pet allergen in the air. So the person who is allergic is exposed to less allergen and feels somewhat better. However this is not a totally effective solution as there will still be some allergen exposure, some immune system stimulation and inflammation. We know that long term inflammatory states are linked to illness such as vascular events eg heart attacks and strokes and seem to also be linked to an increased rate of aging.
Other Important Ways to Improve Indoor Air Quality
- Install some form of ventilation and periodically ventilate the room.
- Use a robotic HEPA vacuum cleaner to clean the floor of dust regularly. This is particularly important for pet hair as the majority of it will not reach the air purifier as it settles out of the air quite quickly.
- Regularly dust the room, ideally just before vacuuming.
So the best air purifier for pets is the Coway 400S, it meets the needs of the pet by being as quiet as possible. It is also in a reasonably large cabinet so keeping high frequency sound to a minimum to help protect their sensitive high frequency hearing.
It is also a great air purifier for humans, as it is specified to have good ultrafine particle reduction. It is not so good as regards smell reduction having a good average carbon filter. If pet odor reduction is your prime concern an iQair Multigas has a superb carbon filter (illustration above), but it is noisier per unit air flow than the Coway 400S and more expensive.
Ignore special “pet air purifier” claims these are cute but a distraction, and sometimes would lead you to buy the wrong air purifier. Any true HEPA air purifier will have no trouble dealing with any pet related airborne particles and odor reduction depends on the amount of activated carbon in the filter. The most important thing is to size the air purifier for the size of your room and take into account your pets hearing.