In homes and business premises, poor air quality has a direct impact on the health of the occupants. Exposure to pollutants, fine particles and pathogens can lead to serious diseases. Follow our tips for choosing the right purifier for your situation.
How does an air purifier function?
A turbine propels air through filters that target certain pathogenic species through physical or chemical processes, by capture or transformation.
The pre-filter, upstream of all the others, captures hairs and other volatile wastes that can hinder the proper functioning of the system. Then, discharged solids, the air circulates in a series of different filters composing the purifier. It is this combination of filters that defines the purification quality of the device, which can be used to deal with particles of at least 0.3 μm (micrometers) such as bacteria and viruses.
The filters making up the air purifiers can be particulate, ionization, combustion, photocatalytic or plasma. Each filter corresponds to a use, a precise filtration to deal with several types of pollutants.
Why purify the air?
The air of our habitats can be polluted by many sources: the paint that covers the walls; the furniture decorating the living room; the road traffic if you live in the city or the factory in the corner of the block or neighborhood.
A purifier therefore cleans the air of the room where it is located and reduce our exposure to pollutants that sometimes prove to be carcinogenic.
Ozone production: health risks
When we talk about an air purifier, we quickly fall on articles mentioning the dangers of ozone. Breathing air containing more than 120μg / m3 for 8 hours a day irritates the mucous membranes and respiratory tract and causes asthma. Aggressive air ionization processes produce large amounts of ozone, incompatible with occupancy by other living beings. For home use, make sure that the purifier does not produce ozone.
VOCs: attention danger
Volatile Organic Compounds are emitted by manufactured products that contain glues, solvents or during the burning of certain materials. Furniture made of chipboard, melamine, laminate flooring, synthetic leathers, foam sofas or mattresses are all sources of formaldehyde that can make your air unhealthy. These formaldehyde are recognized as carcinogenic by health authorities. It is therefore necessary to limit its concentration in the atmosphere.
Air purifier: which filter for which use
The filters that you may encounter on the shelves of a seller of air purifiers are various and numerous; each has its own use:
Particle filter
Characterized by the minimum size of the particles that it can capture, expressed in micrometer (μm) or millionth of a meter and for High Efficiency Particulate Air, a HEPA filter is required. These filters can filter up to 99.97% of particles with a diameter greater than or equal to 0.3 μm. These particles are combustion ashes, pollen, dust produced by tires and brake pads. They are responsible for respiratory diseases such as asthma. You will understand that it is essential to have a particle filter of good quality, especially if you are allergic to pollen, asthmatic or if you live near a major road.
Ionization filter
Ionization is the process by which we add or remove electrons from the atoms of molecules to modify their properties. This filter removes electrons from particles and pollutants in the air. Once these particles become neutral, they are less aggressive.
Combustion filter
Bacteria, fungi and particles are burned upon contact with a surface heated to 200 ° C. The air is of course cooled before it is transmitted again in order to avoid harming the comfort of the occupants.
Plasma filter
When ionized air contains as many free electrons as there are neutral atoms, we speak of plasma. A large amount of energy is used to excite the oxygen molecules that are sent into the room air. They will then oxidize the various pollutants and destroy them. The aggressive nature of this filter is intended for industrial use only, it is therefore prohibited for commercial or residential use.
Purifier: noise nuisance
The airflow and turbine can produce a loud noise that can be annoying in a living room, an office where you need concentration or in any other small place. This requires checking the sound pressure, expressed in decibels (dB). A sound pressure of 50 dB corresponds to a normal conversation, which is already a lot for a room.
Below 20 dB, the device will be more discreet. This result can be obtained by very virtuous devices or at variable speed. The volume of air treated per hour can then be decreased, to limit the noise, or, on the contrary, increased, to quickly renew the air of a room. This turbo mode is valuable for very exposed and occupied premises.
What maintenance for an air purifier
Each of the filters mentioned above brings its stone to the room and their proper functioning. Dust, hair and debris taken from the pre-filter must first be removed by hand.
Each type of filter has an interview of its own. Refer to the manufacturer’s technical documentation to see if the filters are cleanable and how to proceed with doing so. Handle them with care and scrupulously respect the instructions to avoid damaging them. The procedure to follow is often to pass under warm water, over a damp cloth or a soft brush and then let them dry before putting everything back in place again.
Disposable HEPA filters should be replaced periodically. Check the periodicity of the replacement and the price of the consumable to avoid it from being ruined.
Maintenance-free filters, such as combustion ones, need to be replaced when they are no longer working. The availability of these spare parts guarantees a long-term usage.
Consumption and sizing of the air purifier
Power consumption
The nominal power of the device characterizes its consumption during normal operation. For a simple hepa filter, the power required to turn the turbine is merely a few watts (W).
The UV, ionization or combustion filters are more greedy and a multi-level purifier can consume a hundred watts. This power is sometimes more than the device can handle.
Dimension: air treatment cycle
It is considered that to obtain a good quality air, the device must be able to treat 3-4 times the volume of the room in one hour. Multiply the volume of cubic meter of your room by 3 or 4 and you will have the volume of air in cubic meter per hour. If this purifier is intended for a living room, you can opt for a design air purifier. If you want to be able to move it around the house or office, a compact model weighing less than ten kilograms is perfect.
How to regulate hygrometry with an air purifier
The humidity level, or hygrometric rate of the air of a house should be in a range between 30 % and 70 %. Underneath, dry air causes certain respiratory diseases and facilitates the spread of viruses including influenza. Beyond this, excess moisture condenses on cold walls. This moisture promotes the appearance of mold on walls, clothes or anything made from leather. In addition to the unpleasant smell, spores released into the atmosphere cause asthma attacks in vulnerable people.
