Portable Air Cleaners
Portable air cleaners are compact, stand-alone appliances designed to keep the particulate levels of an enclosed space low.
Several models of air cleaners have been found to be able to reduce the level of fine particles in a typical bedroom to an acceptable level during a smoke haze, such as that experienced in Singapore in 1997.
In general, there are three main types of air cleaners available in the market. They are:
a) Ionisers which impart negative charge to the particles that subsequently stick to surrounding surfaces or are filtered out;
b) Electronic air cleaners which removes particles by electrostatic precipitation; and
c) High Efficiency Particulate Absolute or HEPA air cleaners which removes particles by mechanical filtration and diffusion.
In addition, there are also some portable air cleaners that come with a combination of the above features.
A list of these air cleaners is available in the Annex.
The assessment is that the air cleaners in the list will be able to provide adequate protection to a typical HDB bedroom with its doors and windows closed, except for occasional opening and closing of doors. The doors and windows should be opened up occasionally, or at least once a day, to ventilate the room.
For the purpose of smoke haze protection, it is useful to know the Clean Air Delivery Rate (CADR) for smoke of the portable air cleaner and the room size where the air cleaner will be used in order to make an informed decision to purchase it. CADR means the amount of clean air that an air cleaner delivers to a room. A higher CADR indicates greater ability to return clean air to the room. On the purchase of air cleaner, buyers are advised to liaise with the suppliers to obtain detailed product information in ensuring the suitability of the air cleaner to meet individual household needs.