HEPA Filter Guide
HEPA stands for High-Efficiency Particulate Air. But not all HEPA filters are equal. Learn the difference between H13, H14, and "HEPA-type" marketing claims.
What Makes a Filter "HEPA"?
To qualify as True HEPA (H13), a filter must capture at least 99.95% of particles as small as 0.3 micrometres (μm). This is the "most penetrating particle size" - the hardest to capture.
Viruses, bacteria, mold spores, fine dust, smoke particles, pet dander
HEPA Filter Grades Explained
| Grade | Efficiency | Captures | Typical Use | Recommended |
|---|---|---|---|---|
| E10 | 85% | Larger dust, pollen | Basic filtration | — |
| E11 | 95% | Fine dust, some allergens | Entry-level purifiers | — |
| E12 | 99.5% | Most allergens, bacteria | Home purifiers | — |
| H13 (True HEPA) | 99.95% | Viruses, bacteria, fine particles | Medical-grade home purifiers | |
| H14 (Medical HEPA) | 99.995% | Ultrafine particles, pathogens | Hospitals, cleanrooms |
For home use, H13 provides the best balance of efficiency and airflow. H14 is typically overkill and increases energy consumption.
HEPA vs MERV-16: Which Is Better?
MERV (Minimum Efficiency Reporting Value) is an alternative rating system. MERV-16 is increasingly popular for home use. Here's how they compare:
| Factor | HEPA H13 | MERV-16 |
|---|---|---|
| Efficiency at 0.3-1.0μm | 99.95% (H13) | 95% |
| Airflow Resistance | Higher | Lower |
| Energy Consumption | Higher | Lower |
| Filter Cost | £40-80/year | £30-50/year |
| Noise Level | Louder at same CADR | Quieter |
| Best For | Medical needs, severe allergies | General home use |
Our recommendation: For most UK homes, MERV-16 offers 95%+ efficiency with lower running costs and quieter operation. Choose HEPA H13 if you have severe allergies or medical requirements.
HEPA Myths Debunked
Myth: "HEPA-type" filters are as good as True HEPA
Reality: HEPA-type/HEPA-like filters may only capture 85-90% of particles. True HEPA (H13+) captures 99.95%+.
Myth: HEPA filters never need replacing
Reality: HEPA filters should be replaced every 6-12 months depending on use. A clogged filter reduces efficiency and airflow.
Myth: Higher HEPA grade is always better
Reality: H14 filters create more air resistance, requiring stronger fans and more energy. For home use, H13 is usually optimal.
Myth: HEPA filters remove odors and gases
Reality: HEPA only captures particles. For odors and VOCs, you need activated carbon filtration in addition to HEPA.
When to Replace Your HEPA Filter
| Environment | Replacement Frequency | Signs to Look For |
|---|---|---|
| Normal home use | Every 12 months | Slight discoloration |
| Pet owners | Every 6-9 months | Visible hair/dander buildup |
| High pollution areas | Every 6 months | Dark grey/black filter |
| Allergy sufferers | Every 6-9 months | Reduced symptom relief |
| Smokers in home | Every 3-6 months | Brown discoloration, smell |
Related Guides
Compare Filter Options
See our full comparison of HEPA vs MERV filters, including costs, efficiency, and recommendations.
MERV vs HEPA Comparison