Do Air Purifiers Actually Work?
Air purifier can indeed neutralize some of the threat posed by air pollution and by indoor activities. In reality, though, not all air purifiers necessarily live up to their marketing hype.
How do air purifiers work?
Other air purifiers use ionizers to help attract particles like static — negative ions bond to dust and allergens and make them settle out of the air. If you're interested in buying desktop air purifier that uses ionizers, make sure it does not produce ozone, a gas made up of three oxygen atoms that is often marketed as helping break down pollutants, because ozone could be a lung irritant and further aggravate asthma conditions. Usually the air purifiers with ozone will have that listed on packaging or in the marketing descriptions.
What are other ways I can improve the air quality in my home?
The best advice is to address the source of indoor air pollution and ventilate your home. If you are looking to supplement the work of your home air purifiers or see if you can get by without one, we recommended trying these steps to help reduce indoor air irritants:
We looked at developing a better filter that could be placed in a car however we determined this was not practical since the fans in a car are just not strong enough. The result would be much lower air flow. This would create a strain on the fan as well as poorer performance in the air conditioning.
So, it’s a difficult problem to solve given the limitations. In addition, it takes a good amount of energy to move air through a filter that is effective and there is not a lot of power in a cigarette lighter adaptor.
And this leads us to the current car air purifier solutions.
How Car Air Purifiers Work
For the most part, car air purifiers work on the same principles as a room air purifier although they are much smaller in size. It’s more like a mini or personal air purifier with a limited power source.
Here is a listing of the most common technologies. We will examine each in more detail below.
Negative Ion Generator
The negative ionizer works by emitting a negative charge into the air. There is no filter to catch the particles. This is simply an electronic device and most often is plugged into a cigarette lighter. This car air ionizer requires little power.
The concept is that negative ions clean the air of particulates by attaching to the dust, pollen or mold spores and then they are more easily attracted to a surface.
However, this does not address the most common issue and that is gas, smoke and odor removal. The only way a negative ioniser could remove any gas is if it creates ozone. This is problematic since ozone is a lung irritant and considered air pollution. We are not meant to breathe in ozone and should avoid it.
A HEPA air filter is the best technology to remove airborne particulates and it does so safely. The problem we have seen with HEPA filters in car air purifiers is that they are much too small to be effective and/or are not true HEPA.
As we explain in 5 reasons to buy air purifiers, the bigger the filter is and the higher efficiency it has the better it will do in cleaning the air. You simply cannot cut corners and make a tiny filter or one with a low efficiency. It won’t be able to filter much.
Recently, Tesla came out with what they call the Biodefense HEPA filtration system in one of their car models. It seems they did the right thing and built a strong enough fan to power the air through a HEPA filter. The gap that we see with this is that HEPA is not effective for gases. And gases are the primary reason people buy a car air purification system. Gases like car fumes will pass right through the HEPA air filter fibers. For something like cigarette smoke removal, the HEPA air filter will remove the smoke particles but not the smoke odors.
Activated Carbon Filter
A filter with activated carbon is good in removing many of the gases associated with smoke removal and car fumes. The problem here is that it requires a good amount (more than a pound in a car) as well as a good air flow. The car air purifier we has seen do not have strong enough motors or enough carbon to remove the pollutants.
In addition, you simply cannot put a container of active carbon in your car and expect it to clean the air.
Furthermore, carbon is not effective for all gases. You often will want additional gas filter media or a treated carbon to have a more complete solution.
For HEPA and activated carbon to work you need more power and you don’t have that with the cigarette adaptor or enough space in the car for an air cleaner that is effective.
An ozone generator works as its name implies and that is to create ozone. While ozone can be very effective in gas removal it is terrible to breathe in. And extremely bad if you have a respiratory issue like asthma, COPD or bronchitis.
As far as I know car air cleaners are not regulated like room air purifiers for ozone.
The only time you would want to use an ozone generator would be in a car when no people are present to remove odors. For example, if you need to remove smoke odors from a car interior, you could use an ozone generator to “shock” the car.
Other than that, you should stay away from ozone.
An air freshener works by masking odors in a car. It does not remove any odors but rather gives off its own odor so you do not notice the odor you are wanting to avoid.
An air freshener introduces gases into your car. It’s not an ideal solution since you breathe in whatever they give off.
Do Car Air Purifiers Work?
Given what we have described above we have no confidence that a car air purifier will provide the clean air you are looking for.
The problems are real, however the solutions simply are not effective. In my opinion, they are quite gimmicky and if they produce ozone you are introducing pollution into your car. This goes against our philosophy of providing products that are effective and safe. So, this is not a product we have any interest in making or selling.
However, there is one solution we have seen in military use that could be effective but would require an installation in a vehicle. This is like a whole house or commercial air purification system for a car where you have a separate fan and filter bank. To work effectively you would have to give up some space, say in your trunk as well as go through an installation process.
Another solution would be to wear a mask. This will filter out many of the particles however unless you are wearing a respirator with a filter you will likely not be able to filter out the gases. When I am in China and wear a mask, I can still smell the pollution as well as tobacco smoke odors so I know even a N95 mask has limitations.