HEPA Air Purifier FAQ

How does an air purifier clean air?
An air purifier cleans the indoor air by drawing the polluted indoor air into the unit and trapping the particles, allergens and contaminates onto a filter.
What kind of filter does an air purifier use?
Most air purifiers use either a HEPA filter or a washable stainless steel collection cell as their filtration medium. Some air purifiers also use a pre-filter to increase the overall filtration efficiency.
What does HEPA mean?
HEPA is an acronym of High Efficient Particulate Air. To qualify as true HEPA by US government standards, an air filter must remove 99.97% of all particles greater than 0.3 micrometer from the air that passes through. (Particles smaller than 0.3 microns are still trapped by HEPA filters but effectiveness is reduced to less than 99.97%.)
What is the difference between a HEPA type air purifier and an ionic type air purifier that uses washable collection grid?
Even though both technologies are designed to purify air; they don't have a lot in common. One major difference between the two technologies is the filter efficiency. A HEPA type air purifier has much higher filter efficiency than the ionic type air purifier. In addition, most ionic type air purifiers emits ozone, which is a harmful gas that could damage lung tissues.
What is a BioGS HEPA filter? How is it different from a regular HEPA filter?
Conventional HEPA filters share a common problem in which allergens such as dust mites and pollens become trapped on the surface and triggers growth of harmful bacteria and odor. A unique, bioengineered HEPA filter traps and reduces allergens down to 0.3 microns in size, including pet dander, dust mites, pollen and other allergens. Learn more. In addition, clogged filters decrease the efficiency of conventional HEPA air purifiers by trapping and collecting particles and allergens in the filter. After a prolonged period of time, filter efficiency drops dramatically. Whereas the BioGS HEPA air purifier has the capacity to disintegrate allergens on the filter thus the filter efficiency maintains at the highest level during the filter life.
Should I run my air purifier continuously?
To be truly effective, ALL air purifiers should be run continuously. Scientific research confirms that indoor air pollution rapidly returns to pretreatment levels when an air purifier is turned off.
What does the CADR rating mean?
To clean an entire room, all of the air in the room needs to pass through the air cleaner's filter. Air cleaners are rated by the amount of air moving through the filter. This rate is called CADR or Clean Air Delivery Rate. CADR measures the amount of particle-free air being delivered into the room. The higher the CADR rating, the larger the room size that an air cleaner can clean.
What does ACH mean?
An air change per hour translates to how many times an air purifier can clean a room in one hour. For example, 2 air changes per hour shows that an air purifier can clean a room once every 30 minutes. An allergy and asthma sufferer needs at least 4 air changes per hour, which means an air purifier can clean a room at least once every 15 minutes.
Do I have to worry about the annual operating cost of an air purifier? If the answer is yes, how do I determine the annual operating cost of an air purifier?
It is very important to know the annual operating cost before you purchase an air purifier. It would be expensive to operate an air purifier if the filter replacement cost is high and the unit is not energy efficient. You can determine the annual operating cost of an air purifier by adding up the annual electricity cost and the filter replacement cost.

*Annual Electricity Cost = Power Consumption of the unit (Watt) x Rate of Electricity ($/kWh) x Hours of operation (hr)