Good. Now let's check if it is actually working.
Most purifiers sold in India were designed for US or European conditions. India's air is a different problem.
In brief
- Most purifiers sold in India use H11 or H12 filters, not H13. In Indian conditions, that gap matters.
- If your unit is over 2 years old, the motor and filter are likely running below rated performance, even if you changed the filter.
- CADR is routinely undersized for Indian rooms. A unit rated for 150 sq ft will not keep up in a 400 sq ft living room.
- No activated carbon layer means VOCs from cooking, furniture and cleaning products pass straight through.
- Global calibration assumes mild US/EU conditions. Gas cooking, monsoon mold and outdoor PM2.5 are a harder test than most units were designed for.
Full checklist below.
The honest question
Having a purifier switched on is not the same as having clean air. Filter grade, CADR relative to your room, motor condition and calibration for Indian conditions all determine whether yours is actually doing anything, or just running quietly while your air stays the same.
2 to 5 times
How much worse Indian indoor air is than outdoors. US/EU standards are calibrated for much milder conditions.
2 years
When motor and filter efficiency begin to drop. Faster still in Indian humidity and PM2.5 load.
H13
The filter grade needed to capture PM2.5 reliably. Many India-sold purifiers use H11 or H12 instead.
Not all HEPA is the same
The word "HEPA" on the box does not tell you which grade. The difference between H11 and H13 is significant, and Indian air tests every level of it.
H11: 95% capture at 0.3 microns
Common in budget purifiers. 1 in 20 fine particles passes through. Insufficient for Indian PM2.5 loads.
H12: 99.5% capture at 0.3 microns
Better, but 5 in 1,000 particles still get through. Adequate only for mild conditions.
H13: 99.97% capture at 0.3 microns
Medical grade. The minimum for genuinely clean air in a high-PM2.5 environment.
How to check your purifier's actual performance
| What to check | Good | Concern |
|---|---|---|
| Filter grade Check the filter itself or the spec sheet | H13 or True HEPA (H13) | H11, H12, or "HEPA-type" |
| CADR vs. room size CADR divided by 10 is roughly the max sq ft coverage | CADR covers your actual room | Unit undersized for the space |
| Filter age Degrades faster in Indian conditions | Replaced within 6 to 8 months | Over 12 months, likely saturated |
| VOC / activated carbon layer Needed for cooking fumes and off-gassing | Activated carbon pre-filter included | HEPA only, VOCs pass through |
| Motor age Airflow drops as bearings wear | Under 2 years, rated speed | Over 2 to 3 years, reduced airflow even with a new filter |
5 signs your purifier is not keeping up
Can you still smell cooking 30 minutes after the stove is off?
Gas cooking spikes PM2.5 to 200 to 500 µg/m³. If the air hasn't cleared in 30 minutes, your unit's CADR is insufficient for the space, or the filter is saturated.
Do allergies or respiratory symptoms continue indoors?
A correctly sized H13 unit makes a measurable difference within days. No change since you got the purifier usually means: wrong grade, undersized CADR, or a degraded filter.
Does the filter look grey, or has it gone over a year without being replaced?
Manufacturer replacement intervals are based on US/EU conditions: low AQI, minimal cooking. In Indian air, filters saturate significantly faster. A clogged filter restricts airflow while offering little filtration.
Is your room larger than the unit's rated coverage?
Most entry-range purifiers are rated for 150 to 250 sq ft. Indian master bedrooms and open-plan living areas are often 300 to 600+ sq ft. An undersized unit fighting a constant losing battle generates false confidence.
Is the unit over 2 years old and has it never been serviced?
Motor bearing wear reduces airflow even with a fresh filter installed, and it isn't audible. In high-use Indian conditions (8 to 10 months a year), degradation is accelerated.
Why India is a harder test than most purifiers are rated for
Global testing is calibrated for US and European homes: mild outdoor AQI, well-sealed buildings, light cooking, no seasonal burning. India is a different condition entirely.
Indian homes face outdoor PM2.5 from traffic and construction, gas-flame cooking that generates particle loads 10 to 20 times the WHO safe limit, year-round mold from monsoon humidity, and persistent VOC load from incense and cleaning products. A purifier that performs adequately in Munich can be overwhelmed by a single evening in a Mumbai kitchen.
The closest proxy for Indian conditions: CADR 300+ m³/hr, H13 HEPA, an activated carbon layer, running at full speed for at least 2 hours after major pollution events.
Having one is a good instinct. Having the right one matters.
Most people who bought a purifier were right to do so. The question is whether the one they have, at its current filter condition, CADR and grade, is actually cleaning the air in their specific Indian home.
Built specifically for Indian conditions
H13 HEPA. Published CADR. Coverage from 400 to 1,000 sq ft. Engineered for gas-flame cooking, monsoon humidity, and India's PM2.5 and VOC profile.