Air Purifier With a Genuine HEPA Filter
A genuine HEPA filter can capture very small airborne particles, but filter quality is only part of the buying decision. Compare CADR, room…
Setup & accessories
Help matching air purifiers to room size, filter type and household air problems.
Filters & Dust
Replacement filter for a room air purifier
A replacement air purifier filter must match the purifier model or fit dimensions exactly. Learn how to choose between HEPA, carbon,…
Replacement pre-filter foam for a room purifier
Replacement pre-filter foam can protect a room purifier’s main filter from dust, hair, and larger particles—but the wrong foam may restrict…
Carbon filter for smoke and VOCs
A carbon filter can reduce odors, smoke compounds, and some VOCs, but performance depends heavily on the amount and type of carbon. Learn…
How much do replacement HEPA filters cost per year
Annual HEPA filter cost depends on the purifier model, filter price, replacement interval, room conditions, and whether the filter includes…
How Often to Change an Air Purifier Filter
Most air purifier filters need replacement every several months, but the correct interval depends on the purifier, filter type, run time,…
Pre-filter versus HEPA versus carbon layers
Pre-filters, HEPA filters, and carbon layers solve different air-quality problems. Here is what each layer captures, how they work…
Replacement HEPA Filter Compatibility: How to Choose the Right Filter
A replacement HEPA filter is compatible only when it fits the purifier’s model, housing, airflow path, and sealing surfaces. Use the model…
True HEPA versus HEPA-type filters
True HEPA is a defined performance claim, while HEPA-type is a less-specific marketing term. Here is how the difference affects…
When Filter Cost Makes a Cheap Purifier Expensive
A low purchase price does not guarantee an affordable air purifier. Compare replacement filter cost, expected filter life, availability,…
Filter Cost After Year One of an Air Purifier
After the first year, filter costs depend on how often your purifier needs replacements and whether its HEPA and carbon layers come as one…
Setup
Do you need an air purifier in every bedroom
Most homes do not need an air purifier in every bedroom. The right number depends on room size, door placement, airflow, allergies, and…
How Loud Is Sleep Mode in Real Bedrooms?
Sleep mode is usually the quietest setting on an air purifier, but the published noise rating does not tell the whole story. Here is how to…
Where to Place an Air Purifier in a Bedroom
The best bedroom location is usually an open spot with several inches of clearance around the purifier, away from curtains, furniture,…
Energy Use of Leaving an Air Purifier On Overnight
An air purifier’s overnight cost depends mainly on its power draw, fan setting, and your electricity rate. Use a simple wattage formula to…
Should an air purifier sit on the floor or a stand
For most floor-standing air purifiers, a level floor is the simplest choice. A stand is appropriate only if the unit is designed for…
Should You Run an Air Purifier All Day?
Most portable air purifiers can run all day when used and maintained as the manufacturer directs. Choose a fan speed that balances…
Use Cases
Do Air Purifiers Help With Cooking Odors?
An air purifier with an activated-carbon filter can help reduce lingering cooking smells, but a standard HEPA filter mainly captures…
Do Air Purifiers Help With Wildfire Smoke?
A properly sized air purifier with a HEPA filter can reduce fine particles from wildfire smoke indoors. Carbon may help with some smoke…
How They Work
Can an Air Purifier Dry the Air Too Much?
An air purifier does not normally remove moisture from the air. If your room feels dry, check its humidity and consider other causes such…
How an Air Purifier Works
An air purifier draws room air through one or more filters, then sends cleaner air back into the room. The filter type and airflow…
How to measure whether an air purifier is working
A PM2.5 monitor can show whether particle levels fall when an air purifier runs. Use consistent conditions, allow time for readings to…