Written by Neeraj Goel, Founder, Best Air Filter (Fiilters). 10+ years of experience manufacturing HVAC and industrial air filters in Delhi.
A HEPA air filter removes at least 99.97% of airborne particles down to 0.3 microns. That covers dust, pollen, mold spores, pet dander, smoke, bacteria, and most viruses. This guide covers what the rating means, what it costs in India, where it’s used, and how to pick the right one for your AC, room, or plant.
Fiilters has manufactured air filters and industrial filtration systems in Delhi for 10 years, with 1,100+ completed projects across pharma, aerospace, and automotive. The numbers and grades below come from that production and testing background, along with published international standards (ISO 29463, EN 1822).
What HEPA stands for
HEPA stands for High Efficiency Particulate Air filter. A HEPA air filter is a pleated filter made from a dense mat of glass fiber or synthetic fiber strands, each thinner than a human hair.
To earn the name, a filter has to trap 99.97% of particles at 0.3 microns. That size is called the Most Penetrating Particle Size, or MPPS. It’s the hardest particle size to catch, so manufacturers test at that point. This matches the official definition published by the US EPA.
Filters that fall short of this number but still perform well (between 85% and 99.95%) get labeled as EPA filters, or sold loosely as “HEPA-type” or “HEPA-style.” These aren’t true HEPA filters. Checking the actual grade before buying saves you from paying premium prices for basic performance.
HEPA Air Filter grades: H13 vs H14
Two grades matter for most buyers in India.
| Grade | Efficiency at 0.3 microns | Where it’s used |
|---|---|---|
| H10 to H12 (EPA) | 85% to 99.5% | Entry-level purifiers, basic AC filters |
| H13 | 99.95% or higher | Homes, offices, hospitals, general HVAC |
| H14 | 99.995% or higher | Cleanrooms, pharma manufacturing, ICUs |
| ULPA (U15 to U17) | 99.999% or higher | Semiconductor fabs, biotech labs |
For home or office use, H13 is enough. H14 makes sense in pharmaceutical cleanrooms or hospital isolation wards, where the air has to meet a stricter standard. Buying an H14 grade for a bedroom purifier adds cost without adding a benefit you’ll notice. Both classes are recognized under the EN 1822 European standard for high-efficiency and ULPA filters.
How a HEPA air filter actually works
It doesn’t work like a simple screen that blocks anything bigger than its holes. Four separate capture methods handle different particle sizes.
Impaction. Particles larger than 1 micron (dust, pollen, some mold spores) hit the fibers head-on and stick.
Interception. Particles between 0.3 and 1 micron follow the air stream but brush against a fiber on the way through and get caught.
Diffusion. Particles under 0.3 microns, including many viruses, move in random zigzag patterns because they’re light enough to get knocked around by air molecules. That randomness makes them collide with fibers and get trapped.
Electrostatic attraction. Some filter fibers carry a light charge that pulls in ultra-fine particles as they pass.
This is why it catches particles smaller than 0.3 microns even better than particles at exactly 0.3 microns. The 0.3 micron mark is the weak point between interception and diffusion working at full strength, not the smallest thing it can catch.
One limit worth knowing: it traps particles, not gases. If you also want to remove smoke smell, VOCs, or cooking odors, you need a carbon filter alongside it, not instead of it.
Benefits of HEPA Air Filters
A HEPA air filter gives you more than just cleaner-looking air. The measurable benefits are:
- Removes PM2.5. Traps fine particulate matter that ordinary filters let through, the same pollutant that spikes during Delhi’s winter smog.
- Removes dust. Cuts down on the dust settling on furniture and surfaces between cleanings.
- Removes allergens. Captures pollen, pet dander, and mold spores that trigger allergies and asthma.
- Improves indoor air quality. Brings indoor PM2.5 and PM10 levels down closer to the WHO air quality guideline levels.
- Better HVAC efficiency. A pre-filter paired ahead of it keeps the main filter from clogging early, so airflow stays consistent.
- Protects machinery. In industrial settings, it keeps dust and particulate matter away from sensitive equipment and production lines.
- Improves employee health. Fewer airborne irritants in a factory or office means fewer sick days linked to poor air quality.
HEPA Air Filter for AC: what to check before buying
A growing number of buyers want one fitted to their AC, not a separate air purifier. Brands like Airth sell retrofit filters that clip onto the AC’s air inlet and filter air as the AC runs.
Before buying, check 4 things:
- Compatibility with your AC type (split, window, cassette, or FCU)
- Filter grade (H13 minimum)
- Expected filter life (6 to 12 months is typical)
- Installation method (most are DIY, no technician needed)
A retrofit unit costs less than a standalone air purifier and uses the airflow your AC already has. It won’t purify air when the AC is off, so it’s a partial solution, not a full replacement for a purifier running in a room with poor air quality around the clock.
HEPA Air Filter Price in India
Pricing splits into two categories: consumer replacement filters and industrial or custom filters.
| Filter type | Typical price in India |
|---|---|
| Retrofit filter for AC | Rs. 1,000 to Rs. 1,500 |
| Room purifier cartridge | Rs. 2,000 to Rs. 6,000 |
| H13 industrial panel filter | Quote-based, by size |
| H14 cleanroom-grade filter | Quote-based, higher due to testing and certification |
As a reference point, a branded AC replacement filter sells for around Rs. 1,199 on the market right now, and standalone purifier cartridges run higher depending on the brand and filter dimensions.
Industrial pricing doesn’t follow one fixed number, because size, frame material, airflow rating, and certification requirements change from one project to the next. As a manufacturer, we quote these per order rather than listing one number.
Types of HEPA Air Filters
- Room air purifier filters, for home use in bedrooms, offices, and living rooms
- AC retrofit filters, for split, window, and cassette AC units
- Industrial and cleanroom filters (H14), for pharma and electronics manufacturing
- HVAC duct filters, built into centralized ventilation systems
- Medical-grade filters, for ICUs and operation theatres
- Cabin filters, for cars and commercial vehicles
Fiilters manufactures most of these categories in-house, including HEPA filters, room air purifier filters, and cabin filters.
HEPA Air Filter vs pre-filter vs carbon filter
| Feature | HEPA | Pre-filter | Carbon filter |
|---|---|---|---|
| Fine dust and PM2.5 | Yes, 99.97% | Partial | No |
| Large particles | Yes | Yes | No |
| Odors, VOCs, gases | No | No | Yes |
| Typical lifespan | 6 to 12 months | 1 to 3 months | 3 to 6 months |
| Best role | Main filtration stage | Protects the main filter from large debris | Removes smell and gas, not particles |
Most working systems use all 3 in sequence: a pre-filter first, HEPA second, carbon filter last (or alongside). Relying on just one filter type leaves a gap, either in particle removal or odor control.
What HEPA air filters are made from
Most units use one of 3 materials: fiberglass, polypropylene, or polyester. Fiberglass versions use fibers made from silica and other glass compounds, arranged in a random pattern rather than a straight weave. That randomness is what forces particles into the impaction, interception, and diffusion paths described above.
The frame around the filter media matters too. Industrial units use aluminum, stainless steel, or galvanized steel frames, since the frame has to hold shape under continuous airflow without adding resistance. Home purifier cartridges use lighter plastic or cardboard frames, since the airflow and pressure requirements are lower.
A gasket seals the gap between the filter and its housing. A poor seal here lets unfiltered air bypass the filter entirely, which is why industrial installations get tested for leaks after fitting, not just before.
Signs your HEPA air filter needs replacing
- Airflow from the purifier or AC feels noticeably weaker than when the filter was new
- The filter looks visibly gray or clogged when you check it
- It’s been in use for 12 months or more, even if it looks fine
- Allergy symptoms or dust buildup on surfaces increase again after months of being under control
Waiting past the recommended filter life doesn’t make it stop working completely, but it raises resistance to airflow (called pressure drop), which forces the fan to work harder and can reduce the actual amount of air getting cleaned per hour.
HEPA Air Filter uses across industries
- Hospitals. ICUs, operation theatres, and isolation rooms, where infection control depends on medical-grade filters.
- Pharmaceutical manufacturing. Cleanrooms that require H13 or H14 grade filtration to meet FDA and GMP standards.
- Aerospace and defense. Contamination control for sensitive components during assembly.
- Automotive. Cabin filters for passenger comfort, and cleanrooms during manufacturing.
- Homes and offices. Purifiers and AC-mounted units for daily air quality, especially during winter pollution spikes in cities like Delhi.
- Industrial plants. Protecting machinery and worker health with industrial air filters built for continuous use.
How to choose the right HEPA air filter
- Match the grade to the application. H13 for home and office, H14 for cleanrooms and medical settings.
- Confirm certification. Look for ISO 29463 or EN 1822 compliance on industrial filters.
- Check the filter life. Most last 6 to 12 months depending on air quality and usage hours.
- Don’t wash it. Water damages the fiber structure and drops the filtration rate permanently. Replace it instead.
- Buy from a manufacturer who tests filters after production, not just during design. Ask for test reports if it’s going into a hospital or cleanroom.
Why Choose Fiilters as Your HEPA Air Filter Manufacturer?
Fiilters is a filter manufacturer and supplier based in Delhi, with 10 years of industrial experience and 1,100+ completed projects. As a supplier to aerospace, pharma, and automotive clients, here’s what sets our Delhi facility apart:
- Custom sizes. Filters built to your exact panel, duct, or housing dimensions, not just standard sizes.
- ISO manufacturing. Production runs under ISO-certified process control, with testing at every stage.
- Bulk orders. Volume pricing and consistent quality across large industrial orders.
- Delhi NCR presence. A local manufacturing base means faster turnaround for buyers across the region.
- PAN India supply. Shipping and installation support for projects outside Delhi NCR too.
- Industrial experience. 10+ years supplying HEPA and industrial filters to aerospace, automotive, and oil and gas sectors.
- Fast delivery. Production scheduling built around industrial project timelines, not retail lead times.
- OEM manufacturing. Private-label and OEM production for other brands and resellers.
Frequently asked questions
What is the full form of HEPA filter?
High Efficiency Particulate Air filter. It has to remove 99.97% of particles at 0.3 microns to earn the name.
What is the price of a HEPA air filter in India?
AC retrofit filters run Rs. 1,000 to Rs. 1,500. Room purifier cartridges run Rs. 2,000 to Rs. 6,000. Industrial and cleanroom HEPA air filters are quoted per order.
Can I use a HEPA filter for my AC?
Yes. Retrofit filters exist for split, window, and cassette AC units. Check compatibility with your AC type before buying.
Is H14 better than H13 for home use?
H14 filters more (99.995% vs 99.95%), but homes and offices don’t need that level. H14 is built for cleanrooms and medical settings where the extra filtration has a measurable purpose.
How long does a HEPA filter last?
6 to 12 months, depending on air quality and hours of use. A pre-filter ahead of it extends that life by catching larger particles first.
Can I wash and reuse a HEPA filter?
No. Water breaks down the fiber structure and permanently lowers the filtration rate. Replace it on schedule instead.
Get your HEPA Air Filter quote
Looking for a reliable HEPA air filter manufacturer in India? Fiilters manufactures custom filtration solutions for HVAC, pharmaceuticals, hospitals, cleanrooms, automotive, and industrial applications. Contact our team today for a free consultation and bulk quotation