© 丹尼斯陳。好酸 (Flickr) Dyson
© 丹尼斯陳。好酸 (Flickr)
What is HEPA?
Description
HEPA is a type filter and stands for "High efficiency Particulate Air". These devices were actually developed during the Manhattan project to stop the unwanted spread of airborne radioactive material.
These filters are designed in such a way that they can filter out particles down to 0.1 microns in size without any significant pressure drop.
Vaccuum cleaners
Vacuum cleaners work by sucking in air and dirt into a bag and then recycling the air, without the dirt, back into the atmosphere.
Some allergens, such as pollen and dust mites are smaller than the holes in standard vacuum filters and so, go back into the room.
The allergens
For people with breathing problems, this can present a major problem as these allergens are never removed from the environment. With traditional filters, having a small enough mesh to prevent these allergens from being recycled back in the atmosphere would slow the air flow in the vacuum cleaner so much that the vacuum would be practically useless.
Features of HEPA filters
HEPA filters use three separate mechanisms to gradually remove a range of tiny particles from the air flow. Their design means that vacuum cleaners can have very fine filters without experiencing any significant drop in pressure or quality of operation.
What to look for
Choice of the vacuum
When buying a HEPA vacuum, be sure that the filters are sold as easy to remove cartridges. This means that the vacuum cleaner does not have to be taken apart to remove the filter for cleaning purposes.
Additionally, look for vacuums that offer "sealed HEPA" or a " true HEPA air purifier". This guarantees that all the air passes through the filter.
Cheap models
Cheaper models which do not boast this feature may in fact have a HEPA filter installed but, this may be poorly sealed or have additional vents which do not exhaust air to the atmosphere via a HEPA filter.
Improvement in air filtration
Air filtration technology and the way that it is employed is improving all the time. If you suffer from allergies or a breathing related illness, the best approach is to approach a charity which is involved with your specific health condition.
They will be aware of the best new vacuum cleaners and will be able to suggest other ways in order to adjust your life style to improve your condition.