Air
Home air equipment: size an air purifier or a humidifier to the room, match a model number to its replacement filter, and compare the units worth a shortlist.
Every page under this heading is about the equipment that treats the air in a room: what size a purifier or a humidifier needs to be, which filter fits the model you already own, and which units are worth a shortlist. Ratings are cited by the standard that defines them.
Air equipment calculators: inputs you already have, one formula, one answer, with the formula printed so the number can be checked.
1 calculators
Air equipment guides: a question about a rating, a filter or a deal in, the number that decides it out, with the standard cited by name.
2 guides
Air purifier and humidifier parts: a model number in, the filter that fits it out, with the cross-fit alternatives and the maker document that says so.
1 parts
Air purifiers and humidifiers compared on published, certified ratings: what each unit is rated for, what it is not, and which one a given room needs.
2 reviews
Air purifier Black Friday and Prime Day deal check: match the smoke CADR to the room before you trust the discount
An air purifier deal is real only if its smoke CADR is at least two-thirds of the room's square feet (AHAM). The box room size is the 1-air-change figure.
Air Purifier Replacement Filter by Model: Levoit Core 300 to Honeywell HPA300, the Part Number and the Interval the Maker Prints
Levoit Core 300-P takes Core 300-RF (6 to 8 months), Coway AP-1512HH and 200M share set 3304899, Winix 5500-2 takes Filter H 116130, HPA300 holds 3 HRF-R.
Air purifier room size calculator: the smoke CADR a room needs on AHAM's two-thirds rule, and the air changes per hour a given purifier delivers
AHAM's rule: smoke CADR at least two-thirds of the room's square feet at an 8 ft ceiling (room size = 1.55 x CADR); ACH = CADR x 60 / volume. 180 sq ft: 120 cfm.
Best air purifier for a bedroom and a living room: AHAM smoke CADR, ENERGY STAR and CARB listings sort eight units, and the room's square feet decide before any of them
AHAM, ENERGY STAR and CARB listings compared: Levoit Core 300 smoke CADR 143 for a 222 sq ft bedroom, Blueair 211i Max 435 for 674 sq ft, CARB types listed.
Best humidifier for a bedroom: the output, tank, humidistat range, wick interval and watts each maker prints, and why the ultrasonic Auto Mode runs past EPA's 50 percent line
Maker sheets compared: Vornado EV100 1 gal per 24 h, 40 to 60% humidistat, wick 4 to 8 weeks; Levoit LV600HH 300 mL/h, 280 W, Auto Mode 55 to 68% RH, past EPA's 50%.
Humidifier Black Friday and Prime Day deal check: the maker's gallons per day, your tap water and the wick interval decide whether the discount is on the right unit
Prime Big Deal Days run October 6-7, 2026; Black Friday is November 27. EPA says ultrasonic units disperse tap-water minerals as white dust. Check output first.