Four Air Exchanges Per Hour is the standard when it comes to how many times the air in an entire room should be cleaned. This is considered even more important than what the air is actually being filtered down to; as long as the air filtration rate is PM.1 and finer.
Think about it. If clean air is not be delivered to the whole room at an acceptable rate, are you really breathing in clean air?
According to the CDC, the goal is to create a minimum of 4 ACH (Air Changes an Hour) to remove 99% of airborne particles.
Airborne particles, VOC and other particulate usually fall within the range of PM.1-PM10 and thankfully IDEAL Air Purifiers filter >99% of particle matter within that range at a higher than average Air Exchange Per Hour or ACH! That is why we love that brand. According to IDEAL their filters perform as such.