Air purifiers in Delhi: Do they really work during severe pollution?

In Delhi these days, it feels like bad air has become normal. On days when pollution spikes and the Air Quality Index goes off the charts, even staying indoors doesn’t always mean you’re breathing clean air. More and more families are buying air purifiers to keep their homes safe. But do you really need to keep it running all day? And how much does it actually help your health?

How indoor air gets polluted

Even when you’re inside, pollution from outside can still sneak in. As explained in a report by Mint, tiny particles called PM2.5 and PM10 can slip through windows, doors, or small cracks in the walls. Once they’re in, they can go deep into your lungs and even into your bloodstream. Just a short time around this polluted air can make your eyes itchy, give you headaches, leave you feeling tired, and make issues like asthma, heart problems, or a weak immune system worse.

How air purifiers protect you

According to Healthline, HEPA air purifiers can catch up to 99.5 percent of harmful particles. If you keep one running all the time in a closed room, it can really clean up the indoor air. Even when the outdoor air is terrible, a purifier can cut the particles almost in half in just a few hours. According to the Mint report, experts suggest keeping it on around the clock during heavy pollution, kind of like how we never turn off the fridge because we want our food to stay safe.

But purifiers aren’t magic. When AQI shoots past 400 or 500, indoor air can still be moderately polluted. For example, if the outdoor AQI is over 500, indoor levels might hover around 120–200. That’s a big improvement, but it’s still not completely safe by global standards. Homes that aren’t tightly sealed or have open doors let polluted air slip in, which makes the purifier work even harder.

Practical considerations

Running an air purifier all day is usually safe, but it does have some downsides. As per online reports, most air purifiers use about 30 to 60 watts on high, so your electricity bill could go up a little. The filters also fill up faster when pollution is bad and usually need changing every three to six months. If you don’t keep up with them, the purifier won’t work properly and might even release some of the trapped particles back into the room.

Noise is another thing to think about. When pollution is heavy, the purifier has to run on high, and you’ll definitely notice the sound. Running them constantly might slightly shorten their lifespan, but regular filter changes and servicing can keep them working well for years.

Maximizing indoor air quality

To get the best results from your air purifier, keep windows and doors closed and change the filters on time. In bigger rooms or areas that get a lot of outside air, having an extra purifier or a more powerful model can help. While purifiers won’t give you completely fresh mountain-air quality, they can make your indoor air much safer and cut down your exposure to harmful particles until the outdoor air gets better.



Thumb image: Canva (for representative purposes only)