Which air purifier should I buy?

So you’re considering in investing in an air purifier – a great choice! Air purifiers can be beneficial for everyone, particularly those with allergies or chemical sensitivities.

However, with so many brands, filter types and variations on the market, choosing an air purifier can be a bit of a minefield. We’ve written this blog post as a guide to help you identify which type of air purifier best meets your needs. We hope you’ll find this information helpful, but if you’re still stuck, don’t hesitate to call our expert team on 0845 450 5950 or 01453 752216 and we’ll talk you through the options.

 

1. What do you want to remove?

You may know exactly which particles you react to or simply don’t want to inhale. If that’s the case, then this part is easy!

Many people are not sure what particles they want to remove or what an air purifier is capable of taking away. Depending on the make and model, air purifiers are capable of removing the following impurities from your indoor environment:

  • Particles: These can include allergens like pollen, dust mite faeces, dust, mould spores and pet dander
  • Smells: These can be anything from cooking smells to stale smoke to pet odours
  • Chemicals and Volatile Organic Compounds (VOCs): These are ‘off-gassed’ by certain solids or liquids and are common in the home. Some of these are considered harmless – for example foods contain VOCs. However there is a subset of these which negatively affect human health, such as formaldehyde and benzene. You can find VOCs in solvents, some household paints and cleaning products. They can also be off-gassed by items of furniture like memory foam mattresses, carpets and MDF products.
  • Bacteria and viruses: These are rather self-explanatory. They can be trapped in specific filter types or destroyed by air sterilisers.

You might find it helpful to note down which types of impurity you want to remove from your indoor air. This can be useful when you’re shopping online or seeking guidance over the phone.

 

2. How efficient do you need it to be?

With so many filter types available on the market today, filtration efficiency of air purifiers can vary widely. By ‘filtration efficiency’, we are referring to exactly how much of the allergens/particles are removed or destroyed by the air purifier.

There are a great deal of filter types available, but we’ll use HEPA as an example. An air purifier with a True HEPA filter will capture 99.97% of particles down to 0.3 microns. To give you an idea of just how small this is, one micron is roughly 1/75 of the width of a human hair![1]

A HEPA-type filter typically removes up to 99% of particles down to about 2 microns. This efficiency level can vary as the term ‘HEPA-type’ simply means a filter that is similar to but not tested like a True HEPA filter.  

If your allergies are mild or you simply wish to breathe cleaner air at home or work, the efficiency level of a HEPA-type filter may be sufficient for your needs. If you are very chemically sensitive or have severe airborne allergies, we recommend you look for the most efficient filter you can afford.

 

3. Filter type

Some types of filter are considered better than others for removing specific particles. Here’s a brief explanation of the main types of filter:

Carbon filter: these are also known as activated carbon filters. To make carbon into activated carbon, the original charcoal is placed in a heated tank and treated with stream and oxygen to give it a huge number of tiny pores that adsorb smells and odours. Regular activated carbon is excellent at adsorbing organic compounds. Activated carbon filtration will remove VOCs such as Benzene, Toluene, Xylene, oils and some chlorinated compounds. It is possible to increase the number and type of chemicals that can be removed by activated carbon by the addition of additives to the carbon. This type of filter is found in the new MeacoClean CA-HEPA 119x5 air purifier (this has an enhanced activated coconut charcoal filter) and the Roomaid Multizorb filter canister .

Electrostatic filter/ Ioniser: These use an electrostatic charge to ionise particles as tiny as 0.3 microns. These can then be trapped in an electrostatic filter, or in the case of an ioniser, the particles can fall to the floor or surfaces for easy cleaning away. Electrostatic filters and ionisers are often added to air purifiers with existing filters to enhance their efficiency, rather than used alone.  

HEPA filter: HEPA stands for ‘high efficiency particulate arrestance’ and was originally developed by the nuclear industry to filter away airborne contaminants. Nowadays, HEPA filters are widely used in domestic applications. As mentioned above, filters labelled ‘True HEPA’ are tested to a level of high efficiency. HEPA-type filters can have a comparable performance but its efficiency can vary.

Air Steriliser: Air sterilisers don’t just trap particles in a filter. Instead, they actually destroy impurities, or at least break them down into a harmless compound. We offer two types of air steriliser –the Airfree models and the Radic8 units. The Airfree range uses a patented thermodynamic incinerator technology to destroy particles in a ceramic core. The Radic8 range uses the NASA-developed principle of photo-catalytic oxidation (also known as PCO technology) which is a proactive, not passive form of air purification. The Radic8s distribute ‘super oxidants’ into the air to decompose particles into water and CO2. These come into their own when it comes to fighting viruses and bacteria.

 

4. Room size

This is an important point that is often overlooked. All air purifiers come with a recommended room size. We base our recommendations on a rate of 3 air changes per hour, based on a standard ceiling height of 2.2m. This provides a comprehensive level of air cleaning and is consistent with the normal air flow of most rooms.  Manufacturer’s recommendations can be higher or lower than this.

If the information is available, CADR (Clean Air Delivery Rate) can be helpful in determining how quickly the unit cleans the air. Ratings are not available for all air purifiers, but some offer a combined CADR and/or have these broken down for smoke, pollen and dust. The higher the rating, the faster the air purifier will clean the air.

 

5. Running costs

Air purifiers can come with running costs, and that’s not just the power consumption. Many units require regular filter or bulb replacement (generally around every 6 months to a year) in order to keep working effectively. Some come with permanent, cleanable or washable filters. If your unit does require filter replacement, it’s really important to adhere to this to keep your air purifier working properly. A dirty or clogged-up filter will prevent an air purifier from working to its full capacity.

If you purchase an air purifier from The Healthy House which requires replacement filters, we’ll send you a gentle reminder when yours is due for renewal for your convenience.

Some units don’t require any filter replacement at all – for example the Airfree air sterilisers. These are an economical choice as they don’t lose their efficiency over time.

 

6. Noise

We provide noise levels in dB for all our air purifiers, where this information is available. Many air purifiers contain a fan so a small amount of noise is to be expected. Some are very quiet or, like the Airfree units, are totally silent.  A normal conversation is about 50Db. If you are sensitive to noise or want to use your air purifier in a bedroom, you may wish to opt for an air purifier as quiet as possible or a silent one.

We hope this information helps you along your air purifier journey and guides you to a unit which will help improve your symptoms and quality of life. If you’re still not sure, need more information or simply wish to chat to our knowledgeable customer advisors, you can contact us here.


[1] Bacteria World: How Big is a Micron?