KNKA APH4000 Air Purifier with Dual HEPA Filters, AQI Display and Pet Mode

Dual air intakes and side outlets help circulate filtered air through your space, while the KNKA APH4000 offers several settings for everyday household needs.

Its washable pre-filters capture larger particles such as pet hair, and the three-stage filter design also includes a HEPA filter and activated carbon layer.

Choose Sleep, Auto, ECO or PET mode, or select from four fan speeds. The AQI display and colour-coded lights make indoor air quality easy to check at a glance.

Everyday use

For a bedroom or other room up to 350 ft², the purifier is rated to refresh the air 4.8 times per hour. In spaces up to 1,695 ft², it provides one air refresh per hour, making the coverage figures useful for matching its operation to the room. Its dual front-and-back intakes and side outlets support air circulation, while the AQI sensor shows current air quality as you use it.

PET Mode increases airflow to address pet hair, dander and odours. Auto Mode adjusts operation based on air quality, while ECO Mode enters standby when air quality is excellent and restarts automatically when purification is needed. For overnight use, Sleep Mode operates at 22–24 dB. Owners also highlight its quiet operation and airflow, along with its compact size and perceived improvements to indoor air quality.

Why it’s worth it

The washable pre-filter provides a practical first stage for larger particles, including pet hair, and can be cleaned as part of regular upkeep. The other two filter stages include a HEPA filter and activated carbon, with filtration capability for dust, pollen, smoke, odours, pet dander and volatile organic compounds. That combination makes the APH4000 useful for everyday air care in homes with pets, as well as bedrooms and shared living spaces.

Rather than relying on a single fixed setting, you can tailor operation to the moment: PET Mode for increased airflow, Sleep Mode for quieter nights, or Auto and ECO modes for sensor-led use. The AQI display adds a clear visual cue without requiring you to guess which setting may be appropriate. Before first use, remove the plastic packaging from the filters and install them in the purifier. Replace filters every 3–6 months, the replacement indicator signals when a change is due.

Technical details

• Model: APH4000
• Colour: White
• Room coverage: 350 ft² for 4.8 air refreshes per hour, up to 1,695 ft² for one refresh per hour
• Filter: Dual three-stage filters with washable pre-filters and activated carbon
• Modes: PET, ECO, AUTO and SLEEP
• Fan speeds: Four
• Noise level: 22–24 dB in Sleep Mode
• Power: 45 watts
• Dimensions: 19.8D x 34.3W x 44.2H centimetres
• Included: Air purifier, two pre-installed three-stage filters and user manual

Questions before you buy

How does the purifier show air quality? A built-in sensor monitors indoor air, and the AQI display shows the reading with colour-coded lights for a quick visual check.

Can I use it in a larger room? It is rated for one air refresh per hour in spaces up to 1,695 ft². For a faster refresh rate, the stated coverage is up to 350 ft², with 4.8 refreshes per hour.

When should the filters be replaced? The replacement indicator lets you know when a change is due. The recommended replacement interval is every 3–6 months.

Should you buy it?

The APH4000 suits households looking for a room air purifier with flexible modes, visible air-quality feedback and a washable first filter stage. Its PET setting, quiet Sleep Mode and dual-filter airflow design make it a practical fit for day-to-day use in bedrooms and living areas.