The right air purifier for smog is a true HEPA model with a clean air delivery rate (CADR) big enough for the room you use most. For a typical 12 by 14 foot bedroom, that means a CADR of at least 220 m³/h. For a large lounge, look for 450 m³/h or more.
This year the smog arrived early. By late September, Lahore's air quality index was already above 200 and Islamabad and Rawalpindi were hovering around 100, before the usual season had even started. Last winter Lahore touched an AQI of 331, rated hazardous. Indoors, the most effective defence is an air purifier with a true HEPA filter, sized for the room you spend the most time in.
Why smog gets inside your home
Smog is mostly PM2.5: particles smaller than 2.5 microns from vehicle exhaust, brick kilns, crop burning and industry. They are small enough to slip through door gaps, window frames and ventilation, so indoor air in a closed house still carries a large share of the pollution outside.
Closing windows slows it down but doesn't remove what is already inside. An air purifier pulls room air through a filter many times an hour, so the particle level indoors falls well below the level outside.
What to look for in a smog purifier
1. A true HEPA filter
HEPA filters trap fine particles mechanically, the same way in any room and at any humidity. Philips' NanoProtect HEPA filters are rated to capture 99.97% of particles down to 0.003 microns. Avoid purifiers that rely only on ionisers or "plasma": they can produce ozone and don't capture particles the same way.
2. An active carbon layer
HEPA catches particles. Activated carbon absorbs gases and smells, such as smoke from burning rubbish or cooking odours. For smog, a HEPA plus carbon combination is the safest choice.
3. Enough CADR for your room
CADR is how many cubic metres of clean air the purifier delivers per hour. It is the single most important number on the box, and more reliable than the "room coverage" figure, which brands calculate in different ways.
For heavy smog, aim to clean the room's air about five times an hour. With a typical 10 foot (3 m) ceiling, that works out to:
| Room | Floor area | Minimum CADR for smog |
|---|---|---|
| Small bedroom, 10 × 12 ft | about 11 m² | 165 m³/h |
| Standard bedroom, 12 × 14 ft | about 15.5 m² | 230 m³/h |
| Master bedroom, 14 × 16 ft | about 21 m² | 315 m³/h |
| Lounge, 16 × 20 ft | about 30 m² | 450 m³/h |
| Open-plan living, 20 × 24 ft | about 45 m² | 675 m³/h, or two units |
If you're between sizes, go up. A bigger purifier running on a low, quiet speed beats a small one straining on turbo all night.
4. An air quality sensor and auto mode
A built-in PM2.5 sensor lets the purifier speed up when the air gets worse and slow down when it is clean. That saves filter life and keeps the room quiet at night.
5. Quiet sleep mode
The bedroom is where most people need the purifier most, for eight hours a night. Look for a sleep mode around 20 to 30 dB and a display that dims.
Air purifier price in Pakistan (October 2026)
| Model | Type | CADR | Rated room size | Price |
|---|---|---|---|---|
| Canon AP02-265B | Purifier | Not listed | Not listed | Rs 43,900 |
| Philips AC0920 | Purifier | 250 m³/h | up to 65 m² | Rs 49,900 |
| Canon AP03-265T | Purifier | Not listed | Not listed | Rs 72,900 |
| Philips AC3420 | Purifier + humidifier | Not listed | up to 78 m² | Rs 134,900 |
| Philips AC3220 | Purifier | 520 m³/h | up to 135 m² | Rs 139,900 |
| Philips AC3737 | Purifier + humidifier | 505 m³/h | up to 131 m² | Rs 159,900 |
| Philips AMF765 | Purifier + fan | 270 m³/h | up to 70 m² | Rs 189,900 |
| Philips AMF870 | Purifier + fan + heater | See product page | See product page | Rs 229,900 |
Prices as listed on our store on 24 October 2026.
Our picks
Best for a bedroom: Philips AC0920
The Philips AC0920 is the one most homes should start with. Its 250 m³/h CADR comfortably handles a standard or master bedroom, its 2-layer HEPA filter is rated to 0.003 microns, and it shows live air quality on the front. In sleep mode it drops to 20.5 dB with the display dimmed, and it draws only 21W, so running it all night costs very little.
Best for a lounge or open-plan room: Philips AC3220
With a 520 m³/h CADR, the Philips PureProtect Pro AC3220 is the one to put in a big living room. Philips rates it to clear a 20 m² room in under six minutes. Its 3-layer filter combines a pre-filter, HEPA NanoProtect and active carbon, which also helps with smoke and cooking smells.
Best for dry winter air: Philips AC3737 or AC3420
Winter air in Islamabad and Punjab is dry as well as dirty, especially in rooms with gas or electric heaters. The Philips AC3737 purifies and humidifies at once with a strong 505 m³/h CADR, and it can run as a purifier only with the tank removed. The Philips AC3420 does the same job for medium rooms and nurseries. Fill both with clean water and clean the tank regularly.
Best year-round: Philips Air Performer AMF765 and AMF870
If you'd rather have one appliance than three, the Air Performer range doubles up. The AMF765 is a bladeless purifier and cooling fan with a 270 m³/h CADR. The AMF870 adds a heater, so it purifies in the smog season, warms the room in winter and cools in summer. In a large, cold lounge where heating is the main job, a dedicated oil, fan or quartz heater is still the better tool; in a bedroom, the AMF870 saves you running three separate appliances.
Lowest price: Canon AP02-265B
The Canon AP02-265B is the cheapest purifier we stock, and the AP03-265T steps up from it. Canon doesn't list a CADR for either, so ask our team for the rated airflow before you choose one for a large room.
How to get the most from your purifier
- Keep doors and windows closed while it runs. A purifier can't keep up with an open window.
- Run it before you need it. Switch it on an hour before bedtime, then leave it on auto overnight.
- Place it in the open, at least 30 cm from walls and furniture, not behind a sofa or curtain.
- Change the filter on time. A clogged HEPA filter moves far less air. Most Philips models warn you when it's due.
- Clean the pre-filter every couple of weeks in smog season. Dust from construction and roads clogs it fast.
- Don't rely on it alone for heavy smoke. On the worst days, also reduce outdoor activity and follow official health advice.
Running cost
Purifiers use little electricity. At 21W, the Philips AC0920 running 24 hours a day uses about 15 units a month. Larger models use more on high speed, but on auto most of the night they sit at low power. The ongoing cost to plan for is the replacement filter, which depends on how bad the air is and how many hours you run it.
Leaving the purifier on auto rather than turbo is also one of the simplest ways to keep appliance power use down through winter, alongside a lower thermostat on the geyser and heater.
Frequently asked questions
Do air purifiers work against smog?
Yes, for the particles that make up most of smog. A true HEPA purifier with enough CADR for the room substantially lowers PM2.5 indoors, as long as doors and windows are kept closed.
What size air purifier do I need?
Multiply the floor area in square metres by about 15 for the minimum CADR in heavy smog. A 15 m² bedroom needs about 230 m³/h; a 30 m² lounge needs about 450 m³/h.
Which is the best air purifier in Pakistan?
For most bedrooms, the Philips AC0920. For large living rooms, the Philips AC3220.
Should I keep my air purifier on all the time?
In smog season, yes. Run it on auto mode around the clock in the rooms you use most, especially the bedroom at night.
Is a purifier with a humidifier better?
It helps in dry winter air, especially in heated rooms. It needs clean water and regular tank cleaning, so choose one only if you'll maintain it.
Keeping dust down through smog season
A purifier does the heavy lifting, but it works best alongside a few habits. Leave shoes at the door, wipe window sills and ledges where fine dust settles, and vacuum often so that dust doesn't get kicked back into the air. A vacuum cleaner with a fine-dust filter traps it instead of blowing it around, which keeps the Philips or Canon filter in your purifier lasting longer.
