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Can Air Purifier Clean Your Air?
Many people think that by ventilating through window, they can reduce the indoor air pollution. But the truth is it doesn't help anything. Outdoor PM2.5 can infiltrate buildings through windows, doors, and even with closed windows. Outdoor air pollutants can enter the building through leakage, openings, joints, and cracks in walls, floors, and ceilings around windows and doors. Wind and the difference in temperature between indoor and outdoor air both contribute to the movement of air into the building.
One way of improving the air quality inside our homes or workplaces is by using air purifiers. If we know that our indoor air quality is low, or if our neighbourhood or city often experiences air pollution, we may decide that purification is necessary. 
Using an indoor air purifier is a good step especially if household improvements are hard to undertake. For example, you may be renting your home and you are not allowed to make any physical changes, or you may live in an apartment where it is impossible to improve ventilation.
How Air Purifiers Clean Your Home
Air purifiers such as the aria Pure40, clean air by filtering it. Unhealthy air enters the purifier, passes through a filter and comes out cleaner after chemical and biological pollutants have been removed or neutralized.
The exact particles that are removed by an air purifier depends on the type of purifier you use. Many types of air purifiers use High Efficiency Particulate Air (HEPA) filters. HEPA filters can remove 99.5% of airborne particles, including PM2.5, carbon monoxide, dust, and mould spores. Carbon filters are also popular in air purifiers because they are more effective at filtering out gases. The aria Pure40 has three filters which includes a pre-filter, a HEPA filter and an activated carbon filter.
Research Proves Air Purifiers Reduce Indoor Pollution
Research has shown that air purifiers with HEPA filters significantly reduce small pollutants such as PM2.5. One US study conducted over two years (2016-17) found that using HEPA filters reduced indoor PM2.5 levels by 55%, while PM2.5 coming into the home from outside was reduced by 23%.1
When choosing an air purifier, we should pay attention to its Clean Air Delivery Rate (CADR) rating. A purifier’s CADR tells us how fast it can clean the air within a room of a certain size, so purifiers with higher CADR ratings have stronger fans and can cover larger rooms. The rating is determined through a test conducted on a room filled with smoke, dust, and pollen; the levels are measured before and after the purifier is used.
Clean Air Delivery Rate Is Important
The aria Pure40 has a CADR of 350m3/h, one of the highest available in its category. This means that the Pure40 works in large areas as well, and is rated for rooms up to 40m2.
If you are not familiar with Clean Air Delivery Rate (CADR), that's okay we will teach how to calculate the CADR needed in your house.
You just need to calculate the TOTAL VOLUME of your home to see what CADR is needed for 4-6 air changes. If you have a living room and bedroom, and the CADR is enough for 4-6 changes, just 1 purifier might be enough.
For example:
Total home = 40m2
Bedroom = 4x4x3 = 48m3
Living room = 4x6x3 = 72m3
Total volume = 120m3
CADR to achieve 4-6 air changes = 480 - 720 m3/h.
Unlike measurements such as air flow rates and overall capacity, CADR ratings provide a specific measurement of how well a purifier filters out different sized particles. However, it is important to note that CADR ratings are measured when the purifiers are used on the highest setting, and that purifiers become less efficient over time.
Finally, all air purifiers need regular cleaning and filter replacement to function properly. When connected to the nafas app, the aria Pure40 has an automatic filter system which helps us manage our filter’s life, and lets us know when it’s time to get a new one.
References:
https://phys.org/news/2018-09-indoor-hepa-filters-significantly-pollution.html
