Information for using Air Cleaners
Information for using Air Cleaners
Embedded Files
What are Air Cleaners?
What are Air Cleaners?
Air cleaners, also known as air purifiers or air disinfection devices, can help improve indoor air quality by removing or inactivating contaminants. Air cleaners are able to remove respiratory bugs from the air, they can also reduce particulates from outdoor air pollution. They are not a replacement for ventilation, and improving ventilation should always be the first option. However, they may be useful in spaces where ventilation is insufficient and particularly as a temporary measure whilst awaiting ventilation improvements. They can also be useful if the provision of extra ventilation increases the amount of outdoor air pollution in your space.
Choosing an Air Cleaner:
Choosing an Air Cleaner:
There are several types of air cleaners, the two most common are:
High-efficiency particulate air (HEPA) filters
High-efficiency particulate air (HEPA) filters
✓ Capable to capture airborne droplets. They can remove respiratory viruses from the air as these are expelled from the mouth/nose in droplets or aerosols.
✘ Periodic maintenance by changing filters
Ultra-violet germicidal irradiation (UVGI)
Ultra-violet germicidal irradiation (UVGI)
✓ Capable of sanitising air and surface
✘ Should be installed by professionals
✘ If installed or operated incorrectly, can be hazardous to health
Other devices exist but their use is not recommended. Devices using ionisers, plasma, chemical oxidation, photocatalytic oxidisation of electrostatic precipitation are not recommended unless their safety and efficacy is scientifically demonstrated by publicly available test data. If you wish to use these devices seek out independent test data or consult an air quality expert for advice.
It is important to choose an Air Cleaner based on its Clean Air Delivery Rate (CADR) and to use it in conjunction with other ventilation methods.
It is important to choose an Air Cleaner based on its Clean Air Delivery Rate (CADR) and to use it in conjunction with other ventilation methods.
Specifying your air cleaner
Specifying your air cleaner
In order to reduce contaminants in the space your air cleaners need to:
Be sized to deliver an appropriate Clean Air Delivery Rate. As a rule of thumb you should provide 10 l/s fresh air for each occupant. For instance for a space with 100 people and no ventilation you would require a clean air delivery rate of 1000l/s or 3600m3/h. If you have some background ventilation then your clean air delivery rate is the required fresh air minus that delivered by ventilation. However, it can be difficult to estimate the current levels of outdoor air in your venue.
Be able to pull all contaminated air through the device. An air cleaner typically has a small fan and its sphere of influence is small. For this reason you will usually need several small devices rather than one large device
A manufacturer should be able to advise on the appropriate number and size of air cleaners for your venue.
Installation and Operation
Installation and Operation
Follow manufactures guidance for floor air covered by a device and space out accordingly. Be aware that the larger the floor area covered the larger the fan, and therefore the greater the noise generated by the device.
Instead of one large cleaner, multiple cleaners should usually be used. These need to be placed as close as possible to people, in particular in high occupancy areas.
Due to the limited sphere of influence the air cleaners performance will be better in rooms with some ventilation, where there are other forms of air movement in the space.
Follow safety instructions and manufacturer's maintenance recommendations for proper operation and care
Start air cleaners and ventilation before occupancy and leave running for at least an hour after transmission risk has decreased
Performance and Safety
Performance and Safety
Carefully examine manufacturer claims and technical information before purchasing an air cleaner
Be aware that air cleaners can be noisy and be sure you understand the impact of the noise within your venue. In quiet spaces the noise effects may be problematic.
HEPA filters and UV devices are well-understood and are generally safe options. If specifying novel devices be aware they have the potential to create secondary products harmful to health when used in real world. They is why simple HEPA filtered devices are recommended.
Maintenance should be carried out in strict accordance with manufacturers instructions
A designated person should carry out routine operation and care of the air cleaner as part of their daily duties. It is possible for air cleaners to fail to work, or reduce in efficacy without this being realised.
Be aware that air cleaners will not change readings on a CO2 meter as it will not remove CO2 from the air even though it is able to reduce the number of droplets potentially carrying viruses and other particulates.
Page updated
Report abuse