Review on Durable HEPA Filter Set For Honeywell HPA300 Air Purifier - Efficient Replacement Filters For Clean Air by Jillian Sparks

I've got a couple HPA 300 units that I use for general dust reduction. (I have IQ Air and Austin Air units with large charcoal filters for fire season and neighbor's fireplace.) These Durabasics filters weren't a perfect fit, but pretty close. I could swear the air purifier's output diminished slightly but I have no way to measure, other than hold my hand above the unit and see where I feel the airflow.How well do the HEPA filters work? People say they're terrific without any way of knowing. The particles of most concern are too small to see, so unless you have a serious test instrument like a Dylos, there is no way to tell. Like any filter, pulling a lot of air through will collect visible dust so for that, sure, they're worth every penny. I like the fact they're relatively inexpensive as I would rather change them when they are visibly dirty instead of trying to vacuum them, which won't remove the smallest, most dangerous particles and even if it did, releasing them from the filter is the last thing you'd want to do.