Choosing the Best Air Purifier for your Bedroom

air purifierResearch shows that people who sleep in rooms with poor air quality sleep worse. Air quality is especially a problem for people with allergies. Going to bed with a bunged up nose makes falling asleep so much harder. Even if you don’t have allergies but instead live in a town or city next to lots of roads, pollutants in the air has been scientifically shown to decrease sleep efficiency and increase sleep disordered breathing such as snoring or sleep apnea.

That’s where air purifiers come in. Devices whose job it is to make the air clean and fresh. They eliminate all the harmful pollutants such as dust, pet allergens and pollen from the air. For many people, including myself, these devices are an indispensable part of their bedroom.

There’s lot of conflicting information on the Internet about how to choose the best air purifier. Truth is that a lot of this information is written by the manufacturers themselves. They’ll big up the features their own air purifiers use and pooh-pooh the features used by their competition.

In this article I’ll demystify the pros and cons behind the technology used in different air purifiers and give you 5 tips to consider before buying an air purifier.

The 4 Air Purifier Technologies

There’s a whole bunch of technology out there that air purifiers use to clean the air. Some are better than others, and some are just expensive add-ons that you don’t really need. Below I’ve listed out the pros and cons of each of the most commonly used air purifier technologies.

Hepa Filters

Hepa is an acronym that stands for high efficiency particulate air. The filter traps airborne particles that include:

  • Dust particles
  • Mold spores
  • Dust Mite Allergens
  • Pollen
  • Pet Allergens

Manufacturers are only allowed to use the Hepa name if their filter passes rigorous tests. Some filters call themselves “Hepa-like” which means that they haven’t applied for certification, either to save money or because their filter doesn’t meet the high standards.

Pros of Hepa Filters

  • Highly effective at trapping particles – The current Hepa speciation requires filters to trap and remove 99.997% of airborne particles 0.3 microns in diameter. That’s a lot of particles!

Cons of Hepa Filters

  • Needs to be replaced over time – They have a life expectancy usually between 6 months to a few years depending on the brand
  • Doesn’t eliminate odors – Odors like tobacco smoke are smaller than regular particles so they slip right through the filter

Browse Hera filter air purifiers on Amazon

Carbon Filters

Also known as charcoal air purifiers. These filters are designed to remove the smaller particles and gasses that would pass straight through a Hepa filter. They’re often used alongside Hepa filters as a second layer of filtration.

Pros of Carbon Filters

  • Removes odors – Traps fumes, gasses and tobacco smoke within the filter

Cons of Carbon Filters

  • Usually needs replacing – Most carbon filters need replacing over time, so factor the cost of the filter alongside the initial cost of the air purifier

Browse carbon filter air purifiers on Amazon


Ionizers electronically charges particles that travel through the device, causing them to:

  1. Stick to the collector plates inside the device so they can be dusted off
  2. Stick to other particles so they become too heavy to float around in the air, causing them to fall to the ground where they can be vacuumed up

Ionization technology varies. The newer technology is much more effective than the older ones and manufactures don’t explicitly tell you which technology their using so always check the online reviews before buying.

Pros of Ionizers

  • Air doesn’t need to travel though the device to be purified – A strong unique benefit of ionizers. This is due to the fact that charged particles attract other particles, even ones that haven’t been through the device
  • Many come in silent or “whisper” varieties – They don’t need a fan but the ones that do help purify the room quicker
  • Even small devices can be effective – Can be placed by a window or in a corner of a room and go largely unnoticed

Cons of Ionizers

  • The quality of ionizers vary – Always check reviews before buying

Browse ionizer air purifiers on Amazon


Ozone air purifiers have got a lot of bad press on the internet. Some people claiming they can be bad for you and even cause major health problems from using them. Much of this is generated by companies with products that compete with ozone air purifiers. But some consideration is needed before using them.

Ozone is an oxidizer that’s extremely effective at cleaning. It will eliminate mold, bacteria and even some odors and gasses. They’re so good that they’re often used in large scale industrial cleaning operations. The downside is that too much ozone is toxic. Some people are uncomfortable with using ozone so most devices allow you to switch it off.

Pros of Ozone

  • Very effective at cleaning the air – And often just a very small amount of ozone is needed to do so

Cons of Ozone

  • Too much ozone is toxic – Always ensure that the device you’re using is designed for use in the home and operates within safe limits

Browse ozone air purifiers on Amazon

Air Purifier Added Features

In addition to the 4 technologies above, air purifiers sometimes contain these 2 extra added features:

Pre Filters

Air travels though the pre filter before entering the main filter. These filters are designed to trap and collect large particles that would clog up the main filter.

Pros of Pre Filters

  • Increases the lifespan of the main filter – Less hassle dealing with filter replacements and saves you money
  • Most pre filters can be reused – Many can just be vacuumed or rinsed under a tap to remove the trapped particles

Cons of Pre Filters

  • Some pre filters need replacing like regular filters – This can remove much of the cost saving benefit so always check before buying

UV Lights

This technology kills any bacteria, viruses or mold that travels though the filter by shining a UV light on them. Usually used as an added extra alongside other technologies.

Pros of UV Lights

  • Can help sanitize the air – Particularly useful if you’re concerned about mold spreading

Cons of UV Lights

  • Loses its effectiveness over time – Because of the degradation of the UV light, the best ones can last a few years whilst the worst can last only a few months. Replacing the UV light might not be possible

Five Tips to Consider Before Buying an Air Purifier

If you’re interesting in buying an air purifier, here are my five tips to help you choose the best air purifier for your bedroom.

1. Only buy what you need

A lot of the more expensive air filters will contain a load of features you probably won’t ever need.

If you’re only considered about pollen or pet allergies, then all you need is an ionizer or a Hera filter with perhaps a pre filter. If you don’t have a problem with odors, then you don’t need carbon filters. And unless you’re considered about mold spreading, you don’t need a UV light.

Don’t fall into the trap of thinking your bedroom air needs to be hyper clean. Your air purifier just needs to remove what’s most important.

2. Always take into account the lifetime cost of the filters

Selling cheap units that require regular expensive air filter replacements is a common trick by manufactures. Before you buy an air purifier that uses filters, try to find out how long the filters last for and how cheaply a set of replacement filters can be purchased for.

In most cases, buying a slightly more expensive device that contains a reusable pre-filter helps extend the life of the other filters and will save you money in the future.

3. Read the reviews before buying

This is especially true for ionizers because their effectiveness varies depending on the type of technology they use. Unless you can delve deep into the specifications, the only way you can judge its effectiveness before buying is by seeing what other people think about it.

Checking the reviews first is also a good idea for air purifiers that use Hepa filters. Sometimes the reviews will flag up the issue of expensive filter replacements or how long the filters last for.

Pay extra attention to reviews from people who have had the device for a few months or years. They’re the best source of information to decipher the running costs and how much of a difference the air purifier has made to their home. Amazon is a great source for air purifier reviews.

4. If you’re on a budget consider getting an ionizer

There’s many cost saving benefits to getting an ionizer:

  • Ionizers are often a lot cheaper to buy than air purifiers that contain filters
  • They’re relatively energy efficient and you don’t need to have them running all day
  • There’s no expensive filters to replace
  • Even small ionizers can be surprisingly effective

Unless you need the extra benefits of Hepa filtration, just getting a cheap ionizer and running it for 30 minutes before bed can make a huge benefit to your sleep.

5. Use plants as a natural air purifier

With all these new fangled technologies, is easy to forget about nature’s own air purifier. Plants not only help to oxygenate the room, they’re also very effective at removing a wide range of indoor pollutants in the air.

NASA, whilst researching ways to clean the air in space stations, discovered that some plants can remove as much as 87% of airborne pollutants in just one day. They created a list of air filtering plants that you can use to find the perfect plant for your bedroom.