Best air purifiers
You just want the bottom line, don't you? Which are the best air purifiers...
I don't blame you. But here's the thing (and the reason there is more than one answer to that question): There is no cure-all, best-of-the-best air purifier for every single person in every situation.
For information specific to symptoms, click below:
Asthma
Dust
General Allergies
Mold
Pet Dander
Pollen
Smoke
Virus & Bacteria
The value of source control
The first course of action in every instance is source control, that is, identifying the source of the irritant and dealing with it directly. Especially when the source is very active, say a cigarette or pollen through an open window, the air purifier cannot possibly keep up.Take care of the source of irritant, then improve general air quality with a room air purifier.
There are, however, two technologies of air purifier that are consistently better than the rest, especially for all general air quality issues, such as pollen, mold, pet dander and dust mites.
Filtered air purifiers
That's right, classic, filtered air purifiers are still one of the best air purifiers for most general air quality issues.These purifiers use a paper filter to "strain out" typical airborne pollutants, like pollen, pet dander and mold.
The best ones use HEPA filters. In fact, never accept a filtered air purifier that doesn't.
Important rules of thumb for these models:
- Look for a model with a larger CADR (clean air delivery rate) number.
- Look for a model with a larger CFM (cubic feet per minute) number.
Why go with the larger rating?
Because these ratings refer to the fan running at top speed.
You don't want the fans running at top speed at night, no unless you already live near a train station. =)
Larger CADR and CFM purifiers will still have an acceptable number of room changes at their lowest speeds.
CADR number
Many of the best air purifiers have a seal from the Association of Home Appliance Manufacturers (AHAM) that lists three CADR numbers, one for:
- tobacco smoke
- pollen
- dust
AHAM suggests a 2/3 rules when it comes to CADR:
The tobacco smoke CADR number should be at least 2/3 the square footage of the room you will be cleaning.
For example: A 10 ft. by 12 ft. room (10 ft. x 12 ft. = 120 square feet) would require an air purifier with a tobacco smoke CADR of at least 80 (2/3 of 120 square feet).
Please keep in mind, the 2/3 rule for CADR is a minimum. Unless you plan on running your purifier on high at all times (and that will be noisy even on the most quiet models), look for a purifier that is rated well above the size of the room in question.
Consumer Reports says: "Generally, we judge CADR values above 350 excellent and those below 75 poor."
CFM number
Some models do not participate in the AHAM rating systems, in which case they will generally cite cubic feet per minute. It doesn't necessarily mean they aren't among the best air purifiers, but do look closer.
Because this number can be deceptive (the amount of air moved means little if the unit is not efficient), look for 350 or more CFM (many top line machines are 400 CFM).
If you are getting a machine with a smaller CFM rating, run it at high speed if you want quality air cleaning (and with rare exceptions, don't get a machine below 250 CFM. An example of an exception would be a high efficiency model that employs multiple filters such as the IQAir models.)
- Rule 2: Remember to change the filter!
If you buy one that doesn't, a good rule of thumb is to check the filter after six months. Is it black? Change it.
Most filters need to be changed every 6-12 months.
The best air purifiers with filters is the IQAir.
Electrostatic air purifiers
There are some electronic air purifiers that are very effective and could be the best air purifiers for you...... but they come with caveats:
The nice thing about electronic air purifiers is they don't have air filters to clean. Also, they are very quiet since they don't need fans nearly as strong as mechanical purifiers.
But they do need fans. Rule #1: An electronic air purifier with no fan relies on nothing more than natural air circulation and that is simply not enough air cleaning to be useful. These models aren't the best air purifiers out there. Far from it.
Also, they must be cleaned regularly (and can be rendered useless if not well maintained).
More concerning, they give often give off levels of ozone that can be an irritant for many people.
A couple rules of thumb when considering these systems:
- Don't get a system that doesn't have collection plates!
When properly maintained, such systems offer less restriction to air flow than filtered systems while removing fine particulants.
What's so important about collection plates?
Without them, particles aren't captured within the system. Instead, charged particles simple float off and stick to room surfaces and have to be cleaned away. This is the "black wall" effect associated with many early ionic purifiers.
- Clean collection plates weekly, more if they need it.
As particles accumulate, the efficiency of these units drops dramatically, rendering them almost useless without close attention.
Some units come with instructions to soak plates overnight. Most will suggest that you clean them in a dishwasher.
Over time, poorly maintained collection plates can form a residue that lowers the ability of the plate to capture particles. That leaves charged particles in the air, not something you want.
- Can you live with the ozone?
Many everyday electronic devices, like televisions and hair dryers, give off trace amounts of ozone. 50 parts per billion (ppb) is the limit for indoor medical units.
Most, but not all, electrostatic air filter systems give off less than 50 ppb of ozone. But often, as Consumer Reports and other tests have shown over the years, it's not much less.
In general, only electrostatic air purifiers that have very low ozone output should be used indoors.
Back to home