How We Research
Every guide on Mildew Hall starts with one question: will this air purifier suit the room and the problem you have? A unit that suits a bedroom may be a poor fit for a basement or a smoky living room.
Here is how we answer it.
1. We start with your room and your problem
A small office, an open living area and a damp basement each need something different. We check the square footage a model is rated for, and we say when a size or a layout limits your choice.
We also say what a purifier can't do.
It filters the air that passes through it, and it doesn't dry a damp room, fix a leak or remove mold from a surface.
2. We compare specs and features
We look at the rated room size, the CADR numbers the maker gives, the HEPA grade and the amount of activated carbon. We also check the fan speeds, noise range, the controls and whether the filters are washable or must be replaced.
Brands like Levoit, Coway, Winix, Blueair and Shark describe their units in their own words, so we name the brand for each claim. Room-size and CADR figures come from the makers, not from our own lab work.
3. We count the cost of running it
A cheap purifier with pricey filters isn't cheap. We look at how often the filters need replacing, what they cost to replace and how much power the unit draws.
We call out models with filter plans that look costly over a few years.
4. We avoid ozone and ionizer units
We don't recommend ozone generators. When a unit has an ionizer, we say so, and we prefer models where you can switch it off or that list a California CARB certification.
5. We look at buyer feedback
We read what buyers report after living with a model. We look for patterns, like loud fans at top speed, odd smells, broken sensors and filters that wear out early.
One angry review doesn't sink a product. A pattern does.
6. We score each product
Our score weighs specs, features and buyer feedback against what you're shopping for. A model that's great for one reader may score lower in a guide written for another.
Scores spread out on purpose. A 10 is rare.
7. We keep pages up to date
Makers swap filters, rename models and sell look-alike versions. We check each model number and what comes in the box, and we link only new units.
We skip unknown brands with no track record and any unit with a known recall. When we update a guide, the "Updated on" date at the top changes with it.
What our picks are not
Our picks are research, not lab tests. We don't claim to have used every air purifier we cover.
We make no medical promises.
If mold covers a surface, fix the moisture and follow the EPA's mold guidance. For health worries, talk to a doctor.