1 / 7

Product guide

KNKA APH4000 Air Purifier, HEPA, White

HEPA White: The KNKA APH4000 air purifier combines dual three-stage filters with washable pre-filters, air-quality display and PET, ECO, AUTO and SLEEP modes. Its stated coverage varies substantially by room size and refresh rate, so buyers should match the operating claim to their space.

At a glance

Dual front-and-back filter cartridges each use three filtration stages, including a washable pre-filter and activated carbon filter.
PET, ECO, AUTO and SLEEP modes provide different operating settings, with four fan speeds listed.
A built-in sensor and colour-coded display show the claimed real-time air-quality index.
The listing states 4.8 air refreshes per hour up to 350 ft², but only one per hour at its larger 1,695 ft² claim.

Price

$139.99Save 26%

Reference price: ~~$189.99~~

Price checked: Nov 13, 2026

View offer Ahead of Black FridayExplore the selection

Often bought together

Afloia Air Purifiers for Bedroom Large Room Up to 1500 ft², 4-Stage Filter | Washable Pre-Filter for Pet Dander, Dust, Smoke,

$129.99

Activated Charcoal Odor Absorber Deodorizer Odor Eliminator for Strong Odor | Home, Basement, Closets, Shoes, Smoke, Car Air

$20.99

Pros and cons

Pros

Dual filters and washable pre-filters give buyers a reusable first filtration stage.
PET, ECO, AUTO and SLEEP modes, four fan speeds and an AQI display offer several ways to manage operation.
The manufacturer lists CADR values for smoke, dust, PM2.5 and pollen.

Technical specifications

22 specifications

Identity
Brand	KNKA
Model	APH4000
Colour	White

Filtration and airflow
Filter type	HEPA
Particle retention size	0.3 micrometer
Smoke, dust and PM2.5 CADR	226 CFM (384 m³/h)
Pollen CADR	244 CFM (415 m³/h)
Coverage claim	350 ft²
Air refresh claim	4.8 times per hour in rooms up to 350 ft²
Large-room coverage claim	up to 1695 ft²
Large-room refresh claim	1 full air refresh per hour
Listed contaminants	Cigarette Smoke, Dust, Odors, Pet Dander, Pet Hair, Pollen, Volatile Organic Compounds (VOCs), Wildfire Smoke

Modes and controls
Control methods listed	Touch
Modes and display	AQI Display, Dual 3-Stage Filters, PET & ECO & AUTO & SLEEP Mode, Washable Pre-Filter
Fan speeds	four fan speeds

Power and noise
Power configuration	ac_dc
Wattage	45 watts
Noise level	22 db
Sleep-mode noise claim	22-24 dB

Dimensions and installation
Dimensions listed	19.8D x 34.3W x 44.2H centimetres

Certifications and warranty
Specifications met	CARB Certified, DOE Certified, ETL Certified
Warranty description	2-Year Warranty

What to know before buying

Remove the filters' plastic packaging before use. The listing recommends replacing filters every 3–6 months and says to use genuine KNKA replacements.

Listing details to confirm

Coverage statements use different room sizes and refresh rates. The listing title claims up to 1,695 ft² in one hour, while detailed claims specify 350 ft² at 4.8 refreshes per hour and 1,695 ft² at one refresh per hour, with differing stated purification-efficiency figures. Treat these as manufacturer claims and choose based on the smaller-room refresh rate if frequent air turnover matters.

What’s in the box

Included

1 x Air Purifier
2 x 3-Stage Original Filter (Pre-Installed)
User manual

Who is it for?

A good fit for

Buyers seeking an air purifier with dual filters, washable pre-filters and a visible air-quality display.
Pet owners interested in a dedicated PET mode and filtration claims that include pet hair, dander and odours.
Buyers who want selectable ECO, AUTO and SLEEP modes rather than a single operating setting.

Less suited to

Buyers who need a confirmed high refresh rate throughout a room near the stated 1,695 ft² maximum.
Buyers who require independently verified coverage, airflow or filtration performance.

KNKA APH4000 Air Purifier, HEPA, White · photo 2 — Additional product photo 2

Customer reviews on Amazon

4.7 / 5 · 2,907 ratings

5 stars83%83%
4 stars11%11%
3 stars2%2%
2 stars1%1%
1 star3%3%

Customer rating aggregates skew strongly positive, with most ratings in the five-star category, but a smaller share falls in the lower categories. Without comment-level feedback, they do not identify specific strengths, faults or reasons for ratings. Treat the overall pattern as a limited satisfaction signal rather than evidence that the purifier achieves its stated room coverage or airflow.

Frequently asked questions

How large a room does the APH4000 cover?

The title claims up to 1,695 ft² with one air refresh per hour. The detailed listing also states 4.8 refreshes per hour in rooms up to 350 ft², so the appropriate claim depends on room size and desired turnover.

What filtration does it use?

The listing describes two three-stage cartridges, each with a washable pre-filter, a high-efficiency filter and activated carbon. It also lists HEPA filtration.

What modes and controls are listed?

The listed modes are PET, ECO, AUTO and SLEEP, with four fan speeds. Touch is given as the control method, and a built-in display is claimed to show AQI.

What maintenance is specified?

The listing says to remove the filter packaging before use and recommends filter replacement every 3–6 months. It also identifies the pre-filter as washable.