Knowing what sets the best HEPA filter air purifiers apart from the mediocre is becoming ever more important.
Why? Because growing public concern about indoor air pollution has moved many companies to cash in on the business of selling air cleaners.
But these companies often have no experience in the field of air purification. Their products are not always manufactured with the user in mind. Suitability of the technology used, soundness of construction and materials, overall effectiveness, and safety with respect to harmful byproducts may take a backseat to profits.
It’s up to you to sort through the multitude of air cleaner brands, models and bold claims.
What glaring flaws will you find in poor quality HEPA filter air purifiers?
The filter is not really a true HEPA filter
There are many sly dogs who want to capitalize on public familiarity with the term HEPA.
You may see air purifiers that claim to be HEPA-type, HEPA-like, microHEPA, microfiltration, 99% something or another, xxxxHEPA or HEPAxxxx, where xxxx may be any number of buzzwords. Don’t be fooled. HEPA filter air purifiers should plainly state that the filter is true HEPA or medical grade HEPA.
The filter uses HEPA media but cannot certify HEPA performance
HEPA filter media is essential as it is the only filter media capable of trapping 99.97% of particles as small as 0.3 microns.
But while the media may be true HEPA what if, due to poor construction, the filter is not?
HEPA filter media is a fine pleated paper and cheaply made media can suffer cracks at the folds that reduce actual efficiency. Be sure to insist on a medical grade HEPA filter that has been warm rolled to prevent cracks and laser tested to ensure integrity.
A manufacturer should be able to assure you the filter is free of defects and capable of actually performing at the rated efficiency of the media.
Air bypasses the filter, reducing the air cleaner’s efficiency
Many air purifiers are promoted as having true HEPA air filters, but these air purifiers do not have high efficiencies as a unit.
The reason is that the filter is not tightly secured in the housing with airtight gaskets to ensure against air leakage around the filter. These gaps reduce actual efficiency. This problem is often seen in air purifiers made with cheap, soft plastic housings that do not securely fit with the filter.
However, do not dismiss all plastic units. Hard, ABS type plastic is a suitable lightweight alternative to metal housings. This is the chosen material for IQAir air purifiers.
Cheap fan motors with no warranty or a very limited warranty
There is another reason the claim of HEPA filtration is not accurate in poorly designed air purifiers where some of the airflow bypasses the HEPA filter. The motor is at the heart of the problem.
A powerful fan and motor made with properly sealed bearings is an essential component of high quality air purifiers. The amount of clean air delivered to your home is directly dependent on the amount of air you can pass through the filter media. The more the better.
A well sealed system with tight gaskets is going to build up a lot of back pressure that requires a strong motor to overcome. Such a motor must also resist the buildup of heat due to strenuous duty. A suitable motor thus adds considerably to the expense of a quality air purifier. Air purifiers with enough fan power can also be noisy, up to 70 decibels.
In order to offer the public a cheap air purifier, designers start with a cheap motor. To accommodate an inferior motor, air is permitted to bypass the filter. This relieves the back pressure and thus the strain on the motor. It also allows the bypassing air to help cool the motor, thus extending its life and reducing warranty claims. This deliberate bypassing and weaker motor combination also helps reduce noise, which seems to be a concern of many consumers.
However the end result is a poorly performing, inefficient, mass market “HEPA air purifier”.
Price may serve as no guide
Most evil of all, these non-performers may not be “cheap” at all. Some are priced similarly to or even higher than superior quality air purifiers in an effort to be viewed as being of the same caliber.
Who offers top quality true HEPA filter air purifiers?
Each of the companies below manufactures some of the best HEPA filter air purifiers available for home use.
- Allerair air purifiers come in over 100 models, most providing true medical grade HEPA filtration. Allerair offers excellent filtration for an economical cost.
- Austin Air.
- Blueair air purifiers use a special approach to HEPA filtration. In addition to providing a large surface area filter, Blueair filters have larger openings in their polymer based media. This allows a much higher airflow and thus requires a smaller, less noisy fan. The trick in these air purifiers is the addition of electrostatic brushes in the airflow prior to the HEPA element. This charges particles and gets them to “stick” electrostatically to the filter media. Blueair thus offers the quitest HEPA filter air purifiers available.
- IQ Air.