How do air purifiers work?

When it comes to air purifier filters, you’ve got a couple of options, and which one to choose will depend on what you need, and whether you have serious allergies or not.

A HEPA filter (High Efficiency Particulate Air filter) is the one you’ll probably hear about the most - they are considered the gold standard of filters, with good reason. They capture 99.97% of particles in the air, including the real small stuff like dust, pollen, mould spores, smoke and even some bacteria and viruses. If you’ve got allergies, asthma, pets or just are particular about the air you breathe, then a HEPA filter will be your best bet.

On the other hand, if you’re looking for something a bit more budget-friendly and don’t need that extra level of filtration, EPA filters are a solid choice. Ikea's range of air purifiers has EPA filters as an example, and they are relatively affordable. They’re great for everyday dust and allergen control and generally cost less than HEPA filters. However, they’re not as efficient at capturing the tiniest particles, like certain bacteria and viruses, so they might not be ideal if you’ve got serious allergies or respiratory issues. 

There are also some other filter types to consider, depending on your needs. Activated carbon filters are champs at tackling odours and smoke, making them a good add-on if smells are a concern. UV filters can help kill bacteria and viruses, but they work best when paired with a HEPA filter for actual particle removal. Then there are ionic and electrostatic filters, which can handle fine particles but might release a bit of ozone, which isn’t great in high amounts. So, for the best all-around air quality, go for a HEPA filter, ideally with an activated carbon filter for odours. If you’re keeping an eye on costs and just need general dust control, an EPA filter should do the trick. But overall, HEPA is the way to go for maximum performance.

Ionisers are another option for getting clean air, but without using filters. Instead, an ioniser releases negative ‘ions’ into the air, which then attach themselves to the floating dust and particles. They become too heavy to keep floating around, so they clump up and fall to the ground and out of your air.

The cool thing about ionisers is they run pretty silently, and there’s no need to change filters on the reg, because there are none to change. You might, however, find yourself vacuuming your floors more often to clean up the particles as ionisers don’t actually get rid of them, just remove them from the air. There’s still a clean up afterwards to get the offending particles out of your house.

Ionisers also can produce a side of ozone, which as mentioned above, isn’t ideal, especially in high volumes. So while ionisers can do a good job of freshening up your space, they’re best used alongside other air cleaning technologies, like HEPA filters, to cover all your bases and keep your air nice and clean.

Yep! UV light, especially UV-C light, is a powerful tool for killing bacteria and viruses by damaging their DNA, which stops them from reproducing or causing infections. This process - known as UV germicidal irradiation (UVGI), is widely used in hospitals, labs, and air purifiers to disinfect air, water, and surfaces. UV-C light has a specific wavelength (200 to 280 nanometers) that effectively penetrates the cells of germs, disrupting their DNA and rendering them inactive. 

While UV-A and UV-B light (like what you get from the sun) are less effective for disinfection, UV-C stands out as the most potent germ-killer (so don’t go sit in the hot sun for hours when you have a virus.)

However, there are some important details to keep in mind. For UV-C light to be effective, it needs to directly reach the particles, so any shadow or obstruction can reduce its effectiveness. The light's intensity and exposure time also play a crucial role; too little of either, and it might not kill all the germs. Additionally, direct exposure to UV-C light can be harmful to human skin and eyes, which is why it’s often used in enclosed or controlled environments. 

In air purifiers, UV-C lights are most effective when combined with HEPA filters, which capture particles and allow more time for the UV-C light to work its magic. So, while UV-C is a good tool in disinfection, it needs to be used carefully and in the right settings to get the best results.