How to Remove Dust from the Air
One of the key technologies in any air purification system is the filters. To do a good job in removing airborne dust particles from the air you will need 2 or 3 types of air filters.
Pre-Filter to Remove Large Sized Dust
The first filter to look for is called a pre-filter. This can be either plain pleated pre-filter or a carbon pre-filter. Both types serve the same function and that is to catch the large dust particles. Large air particles are filtered from the air by the pre-filter so the HEPA filter will last longer and not get clogged with the big stuff. Some examples include pet hair, , large floating dust or clumps of dust bunnies.
If this carbon pre-filter is made of foam with a sprayed on carbon coating this will provide some odor removal ability. In our experience it works best for light odors.
If you are looking to also remove a challenging odor like the tobacco smoke removal you will not be pleased with the results. There is just not enough activated carbon.
Besides the fan, this is the most important part of your air cleaner when it comes to dust and dust mites.
In the US, filters are rated based on the MERV rating system. This is a scale that goes from 1 to 18. It shows the efficiency of the filter. In other words, it gives a good and simple way to compare air filters.
The problem is very few air purifier brands share their MERV rating. So, it makes it difficult for you to know what you are getting.
Besides the filter rating it's also good to know how much filter media is in the HEPA air filter. This will given an indication for how long the filter can last. The more filter media the longer it should last.
Getting back the MERV filter rating, for pre-filters they are commonly rated around MERV 4.
Anyways, the bottom line is you want a good HEPA air filter. Some are marketed with names include the word HEPA but may or may not meet the HEPA filter standard. The most common is the HEPA-type filter, sometimes called a HEPA-type air purifier.
Activated Carbon Filter to Remove Odors
A carbon filter will necessarily help with the removal of dust and dust mites it does offer benefits in removing odors and making your home smell fresh.
All carbon is not created equally. Similar to the HEPA filters, it's about quality and quantity.
Carbon usually comes from coconut shells or coal. Naturally carbon is not effective in absorbing odors. To make it work it's magic, you first must activate carbon. This is not something you do. Rather it is a process in manufacturing where we heat it until it hardens and cracks. In this state it is considered activated carbon.
With the new cracks and crevices, carbon has the ability to adsorb a wide variety of odors such are cigarette smoke as well as indoor air pollution. The absorption ability is from the quality of the carbon and the amount of carbon in the filter. It's hard to compare activated carbon quality across filters so the default way is to just look at the amount in pounds.
As a general rule of thumb, granular activated carbon (GAC) works better than any sprayed on carbon like you will see in pre-filters. If you live near a highway or have toxic air pollutants like from paint then a strong activated carbon filter is a must.