How to choose the best air purifiers for removing tobacco smoke

Did you know that second hand tobacco smoke contains over 250 harmful chemicals? Some air purifiers are specially designed to remove much much more of these harmful chemicals than others. This is an area we have a real expertise in and one which confuses some people more than most. Read on for our advice on coping with tobacco smoke in the home.

Hepa Filter for Particles

Although most basic hepa air purifiers can remove at least some of the pollution that come from tobacco smoke, if you want to do the job properly then you need to choose carefully. The main thing to bear in mind when choosing the best air purifier to deal with tobacco smoke and its associated odour is that the contamination is split into two parts. Most air purifiers only deal with one of these parts.

Firstly, there is the visible smoke itself, the 'particle' aspect. The smoke particle is filtered out by the Hepa filter. The second (and most difficult to filter out) type of pollutant from tobacco however is the chemical fumes and odours. Because these are gases and NOT particulates they cannot be trapped in a HEPA filter. Gases are so small they fly straight through any HEPA filter completely unimpeded.

Activated Carbon for the Fumes & Odours.

To be certain of also removing the gases you need to ensure that whichever air purifier you choose has not just got a HEPA filter inside but also has an activated carbon filter. Activated carbon is the only type of filter that can adsorb the harmful gases and keep them locked away. Beware however, not ALL carbon filters are the same. Many basic air purifiers which claim to have these filters inside only have an almost insignificant amount of activated carbon inside and therefore naturally only provide a token gesture of protection.

So the type and size of the carbon is directly related to just how much of the pollution is adsorbed. Specialist air purifiers can contain around a kilo or more of genuine activated carbon. Most mass market units found in our High Street stores or an Amazon contain just a token gesture of carbon, often just a lightweight, thin piece of sponge which has been impregnated with a mere dusting of carbon. This token amount is all that is required for the manufacturer to claim that their machine 'contains' carbon and therefore removes gaseous pollutants. The reality is however that only a miniscule amount of pollutants could ever be adsorbed by such a tiny amount of carbon and therefore their benefit is virtually negligible. Always try to choose a machine with actual activated carbon granules in the filter as opposed to a simple carbon impregnated sponge.

What size are the smoke particles?

Smoke particle sizes range from around 0.1 - 1.0 micron, however the average size is from 0.3 to 0.5 microns.

Can air purifiers actually filter out particles that small?

This is a key question! In short, yes, but some are more effective than others. Although most are perfectly capable of filtering out particles as small as 0.3 microns which covers the majority of smoke particles, some filters are actually able to remove particles as small as 0.1 micron, meaning they remove much more of the even more hazardous pollutants missed by standard ones. As an example, the Blueair 680i Smokestop is one of the most powerful air purifiers on the planet, and filters all the way down to 0.1 micron - although it may be a little large for use in smaller domestic areas.

So, will any air purifier with a Hepa filter and a carbon filter effectively remove tobacco smoke and odour?

To a point, however the final piece of the jigsaw is making sure the unit itself is matched to the size of your room to make sure it can 'gobble up' the smoke and fume quickly enough to genuinely make a difference. 

Room Size - (always read the small print).

This is one of the most common mistakes people make when it comes to choosing an air purifier. We have already explained that your purifier needs to contain both a good quality Hepa filter and also a decent activated carbon filter. However, those two elements alone are rendered pointless unless the fan inside the purifier is powerful enough to drag all (not just some) of the polluted air in your room size through those two filters frequently enough for it to stay ahead of the pollution.

Aim for around five air changes an hour to get the best results. Manufacturers will usually indicate what size room their equipment is designed to work in, but this is one of the areas where it is easiest to be misled as they rarely tell you how many air changes an hour they are providing.

For instance if an air purifier claims to be 'Ideal for rooms up to 40m2' , how do you know how quickly it will actually purify all the air in that room size? The answer is you don't. However, if the manufacturer actually specifies this machine 'Provides 5 complete air changes an hour in rooms up to 40m2'. That tells us that this particular machine will purify every bit of air in our 40m2 room at least once every twelve minutes which is excellent.

One example of this is a popular air purifier made by Levoit which is advertised as being suitable for use in rooms up to 40m2. This makes it seem like a great, inexpensive option for larger rooms. However, they do not state how long it will take the unit to actually filter all of the air in that sized room. A quick check of the air volume in the fine print enables us to work out that used in a room of 40m2 that unit will actually take thirty eight minutes to filter the air just once. Therefore it provides around only 1.6 air changes per hour which is not that great. It would however be a decent machine for rooms up to around 15m2 where it would indeed provide around five air changes per hour.

Now compare that to a specialist air purifier like the Roger from Swiss experts Stadler. Their Roger is only advertised as being ideal for rooms up to 20m2, however because they design all their units to provide a generous 5 air changes per hour, even putting it in the same large 40m2 room as the Levoit would see it clean the air around twice as quick than the supposedly more powerful machine. Likewise the Blueair CP7i will do a similar job in even larger rooms and and also uses twin carbon filters for even greater odour and fume removal.  

So the message is, take the advertised room size with a pinch of salt, always ask how many actual air changes the unit will provide in your room – regardless of what is claimed on the box.

In summary

To remove traffic pollution as comprehensively as possible choose a machine with the following criteria:

1. A good quality Hepa filter ( filtering to 0.1 micron if possible, but filtering to not 0.3 will still suffice )
2. An activated carbon filter ( Activated granular carbon not impregnated sponge).
3. Enough air volume to change the air around 5 times every hour in your room size.

For more information feel free to call us directly on 01207 507444, we do love to talk to our customers. In the meantime to view a selection of specially chosen air purifiers with all of the correct criteria mentioned above click here: