Types of Air Purifiers

HEPA Air Purifiers
HEPA filters are an example of mechanical filtration. The advantage to this filtration method is there is no reduction in its efficiency at removing the particulates from the air over time. In fact, a HEPA filter will become more efficient as it collects more particulates, because it is so fine. The only reason you need to eventually change it is because it will start to affect the airflow through the air purifier, which will result in a loss of air cleaning capacity and also may damage the motor because of the heat that may build up. The disadvantage to this kind of filtration is that these air purifiers tend to be noisy, especially on the higher speeds. Their filters are replaceable and can be rather expensive, especially on the more efficient air purifiers which remove more from the air over a shorter period of time.

Electronic Air Purifiers
This type of air purifier can utilize a variety of technologies to clean the air in a room. It works by charging the particulates upon entering the machine by an ionizer, a wiring mechanism that creates an electrical charge with the outcome being the particulates are negatively charged.

One type of electronic model is called an electrostatic precipitator, which consists of a series of metal collection plates that are oppositely charged to the ionized particles. It is important that the metal plates be cleaned regularly (at least weekly) in order to maintain optimal cleaning efficiency.

Another type of electronic air purifier uses a media charged filter. This means it has an electrostatic filter that will collect the particles by being oppositely charged to the ionized particles and therefore able to collect particles as small as 0.1 of a micron. This filter will start out at a high efficiency (as much as 80-90%) but will decrease as the surface area of the filter becomes clogged with particulates. The filter will need to be changed out regularly in order to maintain its highest cleaning ability.

What Type of Air Purifier is Right for Me?
There are several questions you will need to ask yourself before purchasing an air purifier:

How serious is the air quality problem you are trying to solve?
If you are dealing with allergies, the more serious they are, the purer the air needs to be around you. One person with light allergies may feel fine with a cheaper quality air purifier, while somebody else with more severe allergies may find the same machine to be completely ineffective. Also, the exact nature of allergies or sensitivities is an important factor when choosing an air purifier. Different air purifiers are needed for those suffering from multiple chemical sensitivities or asthma. If a person has asthma, it is recommended they purchase an air purifier with a gas filter to control gases and odors, which can trigger an asthma attack. If you wanted to control general cooking odors, you would need a basic gas filter, while cigarette and cigar smoke requires a very large and powerful gas filter. People with multiple chemical sensitivities can react to almost anything, so the correct choice of air purifier is extremely important, since this person could react to the material that makes up the air purifier such as glue on the HEPA filter or out-gassing from plastic parts.

What size area am I trying to clean?
Smaller models are fine for one room air purification, but for larger spaces you would want to consider a more industrial strength model.

What is the upkeep cost of my air purifier?
You need to figure out how often the filters need to be changed and how much they cost. Some air purifiers may have expensive filters, but you may be able to go a longer period of time before they will require changing. It is also helpful if the unit has individual filters to change as opposed to one combined filter to change.