HEPA vs. MERV – What’s the Difference?
First, there are two things you need to know about filters – efficiency and pressure drop.
Efficiency is what % of particles of different sizes can be filtered out.
Pressure drop is how much the filter restricts the air flow.
@joeyfox85 Hi there, can I ask you a HEPA question? Is there any extra benefit to running a HEPA air purifier in say a lounge when the doors are open to outside in summer during a gathering? Or are they ineffective when the air is already being replaced relatively fast?
@miss_jodyo It’s additive. If you get 1 air change per hour from HEPA and 2 ach from windows. That’s a total of 3 ach. HEPA gives 50% increase in that case. It depends on the size of the HEPA and flow through the windows.