Best air purifier for Delhi pollution
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Quick answer
For smog, buy by room size first. Take your room area in square feet, multiply by two thirds, and pick a purifier whose particle CADR is at least that many cfm (about 1.1 times the area in m³/h, the unit Indian makers usually quote). A 120 sq ft bedroom needs roughly 80 cfm, or 136 m³/h. Then look for a true HEPA filter, add activated carbon if smell and gases bother you, avoid ozone-producing ionisers, and check what the replacement filter costs. We do not rank single models: a purifier’s CADR claim is the maker’s, and the sizing rule below does more for you than a name.
Who this is for
Households in Delhi NCR and other smog-hit cities choosing a purifier for a bedroom, a 1BHK or a living room.
Best air purifier for Delhi pollution: the size rule
CADR (clean air delivery rate) says how much particle-free air a purifier delivers. The US EPA’s guide to air cleaners gives a sizing chart: the minimum CADR in cfm is about two thirds of the room area in square feet, for an 8-foot ceiling. Higher ceilings need more. We converted the chart to the m³/h that Indian makers usually quote (1 cfm = 1.699 m³/h).
| Room area | Minimum CADR (cfm) | Minimum CADR (m³/h) |
|---|---|---|
| 100 sq ft (about 9 m²) | 65 | about 110 |
| 200 sq ft (about 19 m²) | 130 | about 221 |
| 300 sq ft (about 28 m²) | 195 | about 331 |
| 400 sq ft (about 37 m²) | 260 | about 442 |
| 500 sq ft (about 46 m²) | 325 | about 552 |
| 600 sq ft (about 56 m²) | 390 | about 663 |
Best air purifier for a 1BHK or a bedroom
A typical 1BHK has a bedroom of about 100 to 150 sq ft and a hall of about 120 to 180 sq ft. By the chart, the bedroom needs about 65 to 100 cfm (110 to 170 m³/h). One purifier in the bedroom, doors closed at night, does more than one purifier struggling to serve the whole flat. If you put it in the hall with the bedroom door open, size it for both rooms added together.
Look at the CADR for smoke or particles, not the “coverage area” on the box. Coverage claims are often based on a different test, so use the CADR number and the table above.
What to look for in a purifier for smog
- True HEPA filter. Portable air cleaners often reach a high CADR with a HEPA (high-efficiency particulate air) filter. Smog is mostly fine particles, so this is the part that counts.
- Activated carbon for smell and gases. The EPA notes the CADR rating covers particles only. For gases you need a carbon or similar filter with a large amount of material; a thin carbon sheet does little.
- No ozone. The EPA advises avoiding air cleaners that intentionally produce ozone, a lung irritant. Ionisers and some electrostatic units can emit some.
- Filter replacement cost and interval. All filters need regular replacement and a dirty, overloaded filter works poorly. In Delhi’s smog season filters clog sooner, so check the price of a replacement before you buy.
- Noise on high speed. You will run it on high for the first hour on bad days. Check the decibel figure on the maker page.
Best air purifier under ₹10,000 for Delhi
A limited budget is best spent in this order: enough CADR for your room, then a true HEPA filter, then the cost of the next filter, then extras such as an app or a display. A big purifier with a high CADR in a small room can run slower and quieter than a small one at full speed. Check current prices on Amazon.in, since they change often and we do not quote them.
How to use it in Delhi NCR
- Keep doors and windows shut while it runs; a purifier cannot keep up with an open window.
- Higher fan speed and longer run time filter more air, so run it on high when the outdoor air is at its worst and lower at night.
- Put it a short distance from walls so air can flow in and out, and keep it in the room where you spend the most time.
- Running cost is our arithmetic: a 50 W purifier on for 24 hours uses 1.2 units a day, about 36 units a month, around ₹288 at an example tariff of around ₹8 a unit. Check your model’s watts.
- A purifier does not replace fixing the source and ventilating when the air outside is clean again; the EPA says the same.
Who should skip an air purifier
If you cannot keep the room closed, or you only want it for a single day, the money may be better spent on well-fitted N95-class masks for going outside. A purifier is for a room you can seal. Also skip any unit that gives no CADR or wattage, or that makes health claims it cannot back up.
Air purifiers on Amazon.in
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Frequently asked questions
Which air purifier is best for Delhi pollution?
One whose particle CADR matches your room, with a true HEPA filter, no ozone and replacement filters you can afford. Size it by the EPA rule: CADR in cfm of at least two thirds of the room area in sq ft.
What CADR do I need for a 1BHK?
For a bedroom of 100 to 150 sq ft, about 65 to 100 cfm (110 to 170 m³/h). If one unit serves bedroom and hall together, add the two areas.
Is HEPA enough, or do I need carbon too?
HEPA handles particles such as PM2.5. Carbon is for smells and gases and only helps if the filter has a lot of material. CADR ratings cover particles only.
How often should I change the filter in Delhi?
Follow the maker’s manual and expect to change it sooner in heavy smog. A dirty filter loses performance, so check it, and the price of a replacement, before buying.
Are ionisers and ozone purifiers safe?
The EPA advises avoiding purifiers that intentionally produce ozone, which irritates the lungs. Prefer a plain filter-based unit.
Sources
Checked on . Rules can change, so confirm with the official page before you travel or buy.