All you need to know before purchasing an air purifier
If you're getting just one, start with the bedroom because that's where you'll be sleeping & where you'll spend the most time.
An air purifier is a simple device consisting of a fan (or two) and filters. Since most pollutants are suspended particulates, these devices work by mechanically separating the pollutants by forcing air through filters. Typically, they don't consume much electricity either, ranging from 15 to 60 watts depending on the filtration capacity and additional features.
Why do you need one?
There are many different sources of air pollution and if you live in a city, chances are, you need one of these already. Breathing cleaner air helps you sleep better, improves lung function and overall health. If someone in the family suffers from allergies, one of these can be quite useful because it will remove common allergens like pollen, dust, pet hair and so on.
How do you choose one?
Air purifiers are rated with a coverage area (square feet). Measure your room and buy something that has a higher coverage. For instance, if your room is 300sq feet, buy something that is rated for 400sq feet or higher. There are multiple brands to choose from now and the rest depends on your budget and the kind of features you require.
How many do you need?
This depends on where you need clean air. If you're getting just one, start with the bedroom because that's where you'll be sleeping and where you'll spend the most amount of time.You can move them from room to room as required but it will take a while for it to clean a room completely. Ideally, each room needs to have one of it's own.
What kind & how many filters do they have?
The primary filter you should look for is HEPA or high-efficiency particulate air filter. It mechanically separates pollutants from the air since it has multiple layers of interlocked fibers. The HEPA is the most expensive type of filter. There's also usually a carbon filter which is used to remove odours and dissolved chemicals.Some of the devices include a washable pre-filter -this catches the larger dust particles, hair, pet dander and so on. You can periodically take it out, cleanwash it and they are cheap to replace. The primary function of the pre-filter is to extend the life of the HEPA filter. So even if your air purifier doesn't have a pre-filter, you can buy one and place it in front of the other filters to lower running costs.
Where should you place it?
Placement is important for maximum efficacy. The clean air delivery rate and effective coverage area is measured with the device in an empty room. If you place it under a table, right up against a wall or in between large pieces of furniture, the amount of air it can circulateclean is reduced. Give it enough room and it should work a lot better. Also keep in mind that they work only with closed doors windows.
Any other filter tips?
Filters need to be replaced periodically. This is where the recurring cost of the air purifier lies.
Some air purifiers have multiple filters and some have compound filters (two or three in one). If you can, find out the cost of the filters and expected life before making a purchase.
Be sure to switch off the air purifier when sweeping the room -it greatly prolongs the life of the unit. You can also use a vacuum cleaner on the front of a filter to clear off accumulated dust.
An ionizer generates negative ions which claims to attract and neutralise harmful particles in the air.Some studies have shown that using ionizers can lead to breathing issues (electromagnetically charged particles can turn into Ozone) so we advise avoiding this feature. Humidifiers use water stored in a tank to boost humidity. Other things you can look for a night mode (extra quiet), WiFi and smartphone control, air quality indicator, display, remote control and temperature humidity sensors.
More about air pollution
Air pollution is not only caused by your car and bursting of crackers. Sources can include seasonal crop burning, construction, burning of fossil fuels in factories, waste landfills and even green house gas emission. Indoor air can also be worse than outdoor air because pollutants accumulate -accelerated by poor ventilation and additional sources of indoor pollution like cooking, pets and chemical cleaning products.
Masks: Do they work?
In short, yes -masks are an effective way of breathing cleaner air. But make sure that the mask is the right kind (not just a piece of cloth or paper) and that it fits well. Two popular brands of anti-pollution masks are Vogmask and Cambridge. Prices range from Rs 1,500 to 2,000. They're available in different sizes, designs and with or without valves (the valves make breathing out a bit a easier). You'll also find a bunch of cheaper options online or at the local chemist but their effectiveness varies. Note that proper (read: effective) masks -like air filters in purifiers -have a limited life. They can't be washed and will need to be discarded after a certain amount of use (usually 200 or so hours).