Key Things You Should Consider Before Buying an Air Purifier

The size of air purifiers matters as it affects the volume of air that it purifies in 60 minutes.

The effectiveness of air purifiers depends on their size and how much air they can filter in an hour.

(Photo: The Quint)

Video Editor: Deepthi Ramdas
Cameraperson: Sumit Badola

If you're a Delhi-NCR resident currently you're living in the most polluted city in the world. The last few weeks have seen Delhi's pollution levels spike to hazardous levels. It's terrible not only for people with breathing problems but also for common folks like you and me.

You also might have been told to stay inside as much as possible. But, that doesn't really help because the air inside your house is said to be two to five times dirtier.

So, how do you tackle this?

Leaving the city is one option but something we can't exercise. I suppose what can help is invest in a good air purifier.

Since everyone isn't an expert in air purifiers I did the hard work of addressing some of the very common questions around air purifiers.

What Kind of Air Purifier Should You Buy?

It's always advisable to invest in models that come with a HEPA filter which eliminates almost 99 percent of common airborne allergens. That includes pollen, dust, mold spores and even pet dander.

HEPA air purifiers are regarded as the most effective options in the market.

Now there are purifiers that cater to specific needs. Like for people who have allergies, asthma or have a lot of smoke in their house. You'll have to research a bit and narrow down on which best suits your needs.

Particles come in a range of sizes. The most commonly measured size is 2.5 microns. Particles of this size are referred to as PM2.5. Comparatively, PM0.1 is much smaller.Known as ultrafine particles, PM0.1 can be inhaled deeply into the lungs, deposited into alveoli to produce a host of harmful effects.

<b>David Hill – Design Engineer, Dyson.</b>

It's advisable to avoid anything that emits ozone. Also, since these things are going to be placed in your rooms make sure they're quiet.

A noise rating to around 50 decibels is what you get from your fridge so that should be ideal. Also, if you more to spend, you can invest in an air purifier you can control via wi-fi which allows you to start and stop it from other locations.

Air purifiers can range from as low as Rs 8,000 up to a lakh!

How Often Should You Change the Air Purifier Filter & How Much Do They Cost?

Air purifiers come in different shapes and sizes. To choose the right size you need to consider the exact size of the room. You should also look at the model’s air change per hour (ACH) rate which is the number of times an air purifier can clean the entire volume of air in a room in 60 minutes.

Most of the air purifiers mention how much of the area they affect in the product specification area. They also show the ACH which helps you make a better buying decision.

Small purifiers are effective in rooms and spaces up to 27 square metres so ideal for small rooms.

Medium size air purifiers can effectively work in rooms between 28 to 65 square metres in size. Large air purifiers can easily work in rooms between 700 to 1,900 square metres.

The effectiveness of HEPA depends on frequent cleaning and change once in 24 months. If HEPA is not changed it gets clogged with fine particles, the suction power &amp; clean air throw will drastically reduce. Hence, it cannot clean as per the recommended coverage.

<b>Kishalay Ray, President,Consumer Electronics, SHARP </b>

Make sure you consider these bits when making that final buying call.

How Long Do I Need to Run My Air Purifier?

It's a misconception that running an air purifier for one or two hours is enough. Humans, cooling and heating systems and even pets introduce new contaminants into the room as well which is why you need to keep running the air purifier whenever you are at home.

Yes, it will result in higher electricity costs but consider it a necessary evil.

Also, at night while sleeping, turn the fan speed down and run it overnight to improve air quality during your sleep.

You don't have to run it when you're not at home. But, you can turn it on a few hours before entering your house which is when a wi-fi controlled air purifier comes in handy.

How Effective Are Safety Masks & What Specification Should I Get?

Since you're not at home and you need to step out and that's where a pollution mask comes in handy. An N95 mask is ideal and can filter up to 95 percent of harmful PM 2.5 particulates. They're good for short-term usage. An N99 mask can filter up to 99 percent of the same but costs a bit more. These masks can be purchased online for anywhere between Rs 150 to Rs 300.

Pollution masks may help briefly but don't protect against pollutants in the longer run.