Is the air you breathe really as clean as you think it is?
Many everyday activities in the home such as dusting, vacuuming, cooking, smoking, cleaning and burning an open fire or wood stove can increase concentrations of airborne particles and chemicals. Because many modern houses are now virtually draft free it means that there is very little circulation of air. The particles and vapours that build up can seriously affect your health particularly if you suffer from hay fever, asthma, rhinitis, eczema or multiple chemical sensitivity. The pollution levels found in many modern homes can be several times higher than the pollution level found on a busy road.
What to consider when choosing a room air purifier?
In order for you to choose the correct air purifier for your situation you need to consider certain factors.
What do you need to remove from the air?
Are you trying to remove a specific allergen, or resolve a particular symptom?
What is the size of the room that you will usually be using the air purifier in?
Do you need to be able to move the air purifier from one room to another?
Air purifiers use various types of filters:
Pre-filters
The function of a pre-filter is to remove large particles.
Particle filters
Particle filters are used to remove particles from the air. These include dust, dust mite fragments and debris, pollens, pet dander, smoke particles and mould spores. Particle filters are either HEPA or Electrostatic.
1. HEPA filters - (High Efficiency Particulate Air) These filters are usually pleated and are very dense – in fact as the filters are used they become denser and more effective until they get clogged up and need to be replaced. A true HEPA filter will remove 99.7% of particles down to 0.3 microns. (A micron is 1/25,000 of an inch. 99% of airborne particles measure 1 micron or less.) Depending on the size of the filter, they can last for several years before they need to be replaced. Because they are so dense they filter very fine particles though the through-put of air is less than with the 3M electrostatic filters. The PermatechTM HEPA filter is a permanent filter that is designed to be vacuumed every few months to keep it clean.
2. FiltreteTM Electrostatic filters - The 3M air purifiers use a Filtrete electrostatic filter that acts like a magnet attracting particles of all sizes. This is less dense than a HEPA filter which means that up to 30% more air can pass through it, giving it a higher CADR (Clean Air Delivery Rate).
Chemical and odour filters
Chemical and odour filters are used to remove chemical pollutants and odours from the air. These can be useful for anyone suffering from respiratory problems but are particularly necessary for chemically sensitive people or for anyone living where pollution levels are high either from traffic pollution or from chemical sprays used in a rural setting.
1. Carbon filters - Carbon filters are usually used alongside particle filters and many of our HEPA air purifiers also use a carbon filter. The carbon filter helps to filter out odours and nuisance level vapours. The carbon removes chemicals to a certain extent but the removal is selective. Carbon will remove some formaldehyde. Carbon filters usually need to be replaced every 6 to 12 months depending on their size and the contamination level.
2. Plasma and titanium dioxide - Plasma and Titanium Dioxide work together to remove viruses, bacteria and chemicals.
3. UV lamp - A UV lamp kills microorganisms and is often used to activate the Titanium filter medium.
Ionisers
Positively charged dust particles become suspended in the air. Ionisers put negative ions into the air that cause positively charged particles to drop. Ionisers also refresh the air, balancing the proportion of positive and negative ions. Some ionisers create a tiny amount of ozone, others create no ozone.
Air sterilisers
Air sterilisers work by actually incinerating air- borne pollutants and are particularly effective for mould allergy. An air steriliser works by convection and does not use a fan to move the air through the unit. Consequently the air movement is significantly less.
Ozone
There are also air purifiers on the market that actually use ozone to destroy pollutants. Ground-level ozone is a poisonous air pollutant with harmful effects on the respiratory system. Ozone is a very unstable chemical and we do not offer these due to the levels of ozone created and because many of our customers can be affected by ozone.
Clean air delivery rate (CADR)
Some air purifiers have a CADR number which indicates the volume of filtered air delivered by the air cleaner. Where a unit has not been tested for CADR no figures are given. There are three CADR classifications - pollen, tobacco smoke and dust. The higher the numbers, the faster the unit filters the air and the larger the room size that the air purifier will effectively clean.
Please use our updated Air Purifiers Chart for a quick comparison of the air purifiers we offer.
