Filter Technologies Compared
| Technology | Removes Particles | Removes Gases/Odors | Maintenance | Recommendation |
|---|---|---|---|---|
| True HEPA | Excellent (99.97%) | No | Replace every 6-12 months | Best for particles |
| Activated Carbon | No | Good (limited capacity) | Replace every 3-6 months | Add-on for odors |
| HEPA + Carbon | Excellent | Good | Replace both filters | Best all-around |
| Ionizer | Moderate | No | None (may produce ozone) | Not recommended |
| UV-C | No | No | Bulb replacement | Marketing mostly |
| Plasma/Ion Generator | Variable | Variable | Variable (may produce ozone) | Avoid unless needed |
HEPA Grades Compared
| Grade | Efficiency at 0.3μm | Common Use |
|---|---|---|
| True HEPA (H13) | 99.97% | Standard for quality purifiers |
| H14 | 99.995% | Medical/clean rooms, premium purifiers |
| HEPA-type/HEPA-like | 85-99% | Budget purifiers (avoid) |
By Use Case
| Need | Best Technology | Key Spec |
|---|---|---|
| Allergies (dust, pollen, dander) | True HEPA | High CADR, bedroom quiet |
| Pet households | HEPA + Carbon | Higher CADR, frequent filter changes |
| Smoke (cigarette, wildfire) | HEPA + Carbon | High smoke CADR |
| Odors only | Activated Carbon | Large carbon capacity |
| Bedroom use | HEPA | Low noise at medium speed |
| Large open space | HEPA | Very high CADR (400+) |
Feature Value Assessment
| Feature | Value | Notes |
|---|---|---|
| True HEPA filter | Essential | The core of effective filtration |
| CADR rating | Very Important | Key performance indicator |
| Multiple fan speeds | Important | Allows noise/performance balance |
| Filter replacement indicator | Useful | Convenience feature |
| Auto mode / sensors | Nice to have | Sensors vary in accuracy |
| WiFi / App control | Optional | Personal preference |
| UV-C light | Marketing | Adds cost, little benefit |
| Ionizer | Avoid | May produce ozone |
Room Size Quick Reference
| Room Size | Minimum Smoke CADR | Recommended CADR |
|---|---|---|
| 100 sq ft | 67 | 100+ |
| 150 sq ft | 100 | 150+ |
| 200 sq ft | 133 | 200+ |
| 300 sq ft | 200 | 300+ |
| 400 sq ft | 267 | 400+ |
| 500 sq ft | 333 | 450+ |