FAQs: air purifiers and humidifiers

These remarks are intended mainly for Blueair air purifiers and Stadler Humidifiers, but may be useful for other makes of air purifier as well as answering general questions that customers often ask us.

Maintaining and Cleaning your air purifier: General

Keep your filters up to date: this keeps your purifier working at top performance. Blueair filters need to be replaced every 6 months

How to change the filter in Blueair air purifiers? Procedure depends on model, as follows:-

200/ 300 series: open the swing door and pull out the flat fllter pack by the tab at the top. Note the orientation of the filter. Place the new filter in the same orientation (with the black side facing in towards the machine and the white side facing outwards). Close the door and resume operation.

270E model: At the same time as you change the filter, reset the filter timer by opening the small panel on the top of the machine and holding down the "Timer" button for around 10 seconds

400 series: open the swing door and slide out the fllter block. Note the orientation of the filter. Place the new filter in the same orientation (with the black side facing in towards the machine and the white side facing outwards towards the air intake). Close the door and resume operation.

500/ 600 series: remove the grey top panel of the purifier by holding it by the narrow edges, press down with your thumbs and pull up. The panel clips onto the top and should come off easily. You will see three filters: one on top of the purifier and two at the sides. Lift off the top filter, then pull out the side filters by the tabs, noting the orientation of the filters. Throw the filters away and replace with new filters in the same orientation: the black side of the filter should face up/outwards. Reset the magnetic timer on the side of the purifier by removing and then replacing the batteries.

All models: while you replace the filters, clean the air intake grids using a vacuum cleaner with the broad head removed (use a brush attachment if you have one). With the 500/600 series be sure to clean the grids on the underside of the air purifier. If necessary these can be removed and cleaned under running water for more thorough cleaning.

How to maintain my Blueair purifier at peak performance? Aside from keeping filters up to date, the most important thing is to keep the air intakes clear of dust and fluff by vacuuming them. You can also vacuum the prefilter (white, corrugated side of the filter) to keep this clear of fluff.

My prefilter has turned grey, what should I do? The white, corrugated side of the filter turns grey in normal use. This does not impair the HEPA filter performance. But remember to replace filters after 6 months (especially important in Beijing where pollution levels are relatively high).

My prefilter has a lot of fluff on it, can I clean it? Yes, clean it with a vacuum cleaner with the head removed (and a brush attachment if you have it). This will help keep air flowing freely.

Choosing, placing and using air purifiers

Where should I put my air cleaner? An air purifier can be placed anywhere in a room (since air moves around a room relatively quickly). Make sure the air intake vents are not obstructed: in particular if you are using a 200 series Blueair make sure there is a gap of a few inches between the air purifier and a wall to allow air to circulate freely.

How many air purifiers do I need for my home and what sizes? We sell purifiers in several different sizes (so that you can use a small and quiet model in a bedroom, for example). Size estimation is done according to room square meters floor area (to keep things simple) so you can get an estimate of what you need by measuring your room sizes and then checking against our models page. If you would like Torana to visit your home to check air quality and estimate what purifiers you need we can do this for you at no charge (Beijing residents only). Call our store on 010-8459 0785 to arrange an air quality check and assessment.

Should I run my air purifiers continuously, even when I am not in the house? Yes, we recommend running purifiers 24/7. They are designed for this, use little power (similar to a medium sized light bulb or less) and you will find that running them continuously (eg on a medium setting) gives better results and helps keep the entire house cleaner with less dust.

What setting should I use? Generally, we recommend using a medium setting for most of the time: many people simply place the air purifier on a medium setting and leave it running in that way permanently. The HEPAsilent setting (lowest fan speed) is designed for use in a bedroom at night since it is very quiet. Keep the bedroom door closed to reduce air circulation and give the air purifier the maximum chance to clean the air in the room thoroughly. Conversely, during the daytime on heavily polluted days (eg when the AQI score is over 250 or 300) you may want to turn the air purifiers up to the maximum setting for an hour or two.

Can I use air purifiers together with my air conditioning system? Yes, there is no interaction between the two. Individual aircon units that have a box inside a room connected by a pipe to a box on the outside do not bring in any air from the outside so do not affect air purifier performance. Apartment buildings with recirculating air conditioning/ heating systems do bring in some air from outside so if you have this type you may want to consider a slightly larger air purifier model than that indicated by the room size to cope with the extra air inflow.

Health related questions: ozone, asthma and Volatile Organics (VOCs)

Will an air purifier help with my asthma? This depends on what is causing your asthma: in many cases it is triggered or exacerbated by dust (pet dander, mold spores, pollen, ozone, general pollution). Air purifiers will reduce all of these contaminants and so may help reduce asthma. Based on experience we find that sleeping with a good air purifier running is one of the most helpful things for reducing asthma attacks. If you suspect environmental cause(s) you should also visit your doctor for advice since tracking down the cause can also help.

Do Blueair purifiers make ozone? No. Blueair purifiers are engineered to the highest standards and fitted with electrical suppression to eliminate ozone. Blueair purifiers are certified 100% ozone free by external testing laboratory.Blueair purifiers fitted with a charcoal filter stage (this is standard in all purifiers sold by Torana) absorb ozone and will protect you from ozone from external sources.

Can air purifier filters release ozone later? No, because charcoal filters work by breaking down the ozone into normal oxygen, so there is no ozone to release.

What is an electrostatic air purifier? This is a type of purifier that has no filter, but two plates charged up to high voltage to attract pollution particles instead. We suggest you NEVER use an electrostatic purifier since these can make significant amounts of ozone. This type of purifier was common a few years ago but has now largely disappeared due to safety concerns. We occasionally encounter customers in China who have this kind of purifier, however.

Please note: Blueair does not make or sell any electrostatic air purifiers.

What are the health effects of breathing Beijing air? Please refer to our pages on Beijing air pollution and on PM2.5 pollution (fine particulate pollution).

How much of an issue is ozone in Beijing? We have been following the measurements made by the US Embassy over the past couple of years, and the ozone level nearly always seems to be in the "Good" range of their scale. In comparison the PM2.5 particulate score is often higher. We take this to mean that the most important issue here is particulate pollution rather than ozone concentration.

What is sick building syndrome? This is a hard-to-pin-down set of symptoms experienced by people working or living in buildings that have been recently renovated. Symptoms include headaches, mild nausea and irritation due to bad smells. Many decoration materials used here have odor issues, especially paints and glues. With mild cases a purifier fitted with a charcoal filter may help reduce the odors and volatile organics in the air. With serious cases the only solution is to vent the building for 1-3 months to allow solvents etc to disperse.

What are the sources of Volatile Organics (VOCs) in Beijing? These commonly come from fresh paint, glues used in decoration, varnish on furnishings, foam in soft furnishings and synthetic carpet tiles (especially the type with a black foam backing).

How to avoid problems with VOCs? The best method for avoiding problems with VOCs is to work closely with your building contractor or landlord to ensure the materials used in decoration work are of good quality, eg use reputable international paint brands (Dulux, Nippon), not generic materials. Specify screws or pop rivets to be used to fix wall treatments, not glues. Monitor the work on-site on a regular basis (most problems are due to communication issues with sub-contractors, which can be spotted by keeping an eye on work, eg watching out for glue use).

Select furnishings carefully, check soft furnishings, carpets and varnished furniture before buying (what does the store that displays them smell like? If it smells of glue or varnish beware!). It is very difficult to measure VOCs in the home, but your nose is your best guide.

Air purifier with charcoal filters (eg Blueair purifiers) can help with midl cases of VOCs, but the best cure is prevention.

My drains smell, what can I do? This is a common problem in Beijing properties, it is caused by absent or ineffective water traps beneath drain holes, and it is especially a problem in the winter months. First of all, pour water down the drain in case the problem has been caused by the trap drying out. If that fails, the best solution is to fit drains with proper U-bend traps or to seal off unused drains altogether. Mild cases can be dealt with by placing a ziploc bag half-filled with water over the offending drain cover to prevent gas escaping. As with VOCs, air purifiers with charcoal can help with mild cases of drain smell, but the best solution is to tackle the problem at source.

Faults and Technical questions

My Blueair purifier suddenly stopped working, what can I do? This problem is usually caused by the grey plug on the underside of the purifier working loose (300, 400, 500, 600 series). Just tilt the purifier and push the plug in firmly. If that doesn't fix the problem consult the vendor.

Can I change the voltage of my Blueair purifier when I return home? If you have a 400, 500 or 600 series the voltage can be changed easily (eg from 220v in China to 120v in the USA). We can do this for you before you leave, if you need. The 200/300 series purifiers cannot be voltage-changed.


Can I use my air purifier together with a humidifier? Yes, in fact we recommend using both in Beijing, especially during the winter time. Make sure your air purifier and humidifier are at least 1 meter apart. Do not use humidifiers that make a mist (eg "ultrasonic" or "sonicator" models), since these create dust (especially when you use Beijing tap water in them) and the dust will reduce the performance of the air purifier. Instead, use a passive evaporation humidifier (see our humidifiers page for more details).

My ultrasonic humidifier makes white dust, is this a problem? Yes, this is caused by using Beijing tap water or mineralized bottled water in an ultrasonic humidifier. This makes a very fine dust of water salts when the mist evaporates. This is harmful for your lungs and also bad for your air purifier. You need to get a different kind of humidifier (see previous question).

Should I clean my humidifier? Most certainly, yes! Beijing water contains lots of salts and these can deposit on the inside of a humidifier (in a similar way to salts building up inside a kettle). The simplest and cheapest way to clean a humidifier is to buy white vinegar and to soak the humidifier for an hour or so once every 1-2 weeks. The Stadler TOM model has a special setting for doing this (the humidifier runs and cleans itself but the fan does not operate). You can also use proprietary descalers in powder or liquid form for this purpose.