> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sonohealth.com/llms.txt
> Use this file to discover all available pages before exploring further.

# How the AirPro 3-Stage Filtration Works

> Learn how the AirPro's 3-stage HEPA 14 filtration and UV-C sterilization removes 99.9% of particles, allergens, mold, and VOCs from indoor air.

The AirPro uses a multi-layer approach to clean indoor air. Each stage targets a different category of pollutant, ensuring that the air leaving the purifier is free of particles, odors, and pathogens.

## The Filtration Process

Air passes through four distinct stages before returning to your room:

### Stage 1: Pre-Filter

The pre-filter is the first line of defense. It captures large airborne particles before they reach the main filter:

* Dust and lint
* Hair and pet fur
* Large pollen grains
* Visible debris

The pre-filter extends the life of the HEPA 14 filter by preventing large particles from clogging it. It can be vacuumed or dusted periodically rather than replaced.

### Stage 2: HEPA 14 with Antibacterial Coating

The core of the AirPro's filtration system is a medical-grade HEPA 14 filter with an antibacterial coating. This filter captures **99.9% of ultra-fine particles as small as 0.1 microns**, including:

* Dust mites and their waste
* Mold spores (including black mold)
* Pollen (all types)
* Pet dander
* Bacteria
* Fine particulate matter (PM2.5)

The antibacterial coating prevents captured microorganisms from growing on the filter surface.

### Stage 3: Activated Carbon

After passing through the HEPA 14 filter, air moves through an activated carbon layer. Activated carbon uses adsorption -- a chemical process where gas molecules bind to the carbon surface -- to remove:

* Volatile organic compounds (VOCs) from paints, cleaning products, and furniture
* Smoke and tobacco odors
* Cooking smells
* Chemical fumes
* Formaldehyde

### Stage 4: UV-C Sterilization

The final stage uses UV-C germicidal light at 254nm wavelength to neutralize any remaining pathogens that passed through the physical filters. UV-C damages the DNA and RNA of microorganisms, rendering them unable to reproduce.

## Filtration Technology Comparison

| Technology       | What It Removes                 | Particle Size       | Odor Removal | Pathogen Kill |
| ---------------- | ------------------------------- | ------------------- | ------------ | ------------- |
| Pre-Filter       | Dust, hair, lint                | > 10 microns        | No           | No            |
| HEPA 14          | Fine particles, allergens, mold | Down to 0.1 microns | No           | Captures only |
| Activated Carbon | VOCs, smoke, odors              | Gas molecules       | Yes          | No            |
| UV-C Light       | Bacteria, viruses               | N/A                 | No           | Yes           |

## 360-Degree Airflow Design

The AirPro draws air from all directions through its 360-degree intake design. This eliminates dead zones and ensures that air throughout the room passes through the filtration system. In a 430 sq ft room, the AirPro processes all the air in just 10 minutes.

## Why Multi-Stage Filtration Matters

Single-technology purifiers leave gaps. A HEPA-only unit captures particles but does nothing about odors. A carbon-only filter removes smells but lets fine particles through. UV-C alone cannot capture particles at all.

The AirPro's multi-stage approach addresses the full spectrum of indoor air pollutants in a single pass. Each stage handles what the others cannot.

***

**Related:** [HEPA 14 Filtration](/air-purifier/hepa-14-filtration) · [UV-C Sterilization](/air-purifier/uv-c-sterilization) · [Air Quality Guide](/air-purifier/air-quality-guide)