An air purifier is an electrical appliance that draws air in through a variety of filters to reduce dust particles, smoke, chemicals, pollen and bacteria to create an invigoratingly clean living or working space. There are various types of replaceable filters used in each unit, the most popular being the HEPA.
Air purifiers come with various types of filters or filtration aids. These include:
When choosing an air purifier make sure you select the one with a filter suitable for your needs:
Pre-filters trap larger particles prolonging the life of the main filter. Pre-filters are usually either washable or may be vacuumed to keep them clean.
HEPA filters (High Efficiency Particulate Air) remove 99% of particles between 0.3 and 3 microns. including; dust, moulds, pollen, mould spores, pet dander, smoke odours, and some chemicals. Highly efficient, these filters are usually more expensive than other types of filters.
To meet the minimum requirements of a true HEPA filter, the filter must be tested and certified to prove that it will remove at least 99.97% (9,997 out of 10,000) of particles 0.3-micron in diameter from the air passing through the filter. Particles of that size are about 300 times smaller than the diameter of a human hair, and 25 to 50 times smaller than we can see.
Electrostatic filters clean the air using static electricity, by attracting airborne particles that stick to the filter. They are quiet to run and competitively priced. The filters help to remove airborne dust, particles such as smoke, pollen, mould and dust mite faeces.
Carbon filters are super porous and attract, absorb and neutralise organic gases, odours and some chemical compounds. These gases and chemicals are not removed by other types of air purifier filters.
Activated carbon is a form of carbon that has been treated to make it extremely porous giving it a very large surface area for absorption. One gram of activated carbon has a surface area about one tenth the size of a football field.
If you would like to remove smells, gases or some chemicals from the air in your home an activated carbon filter is a very effective part of an efficient air purifier.
If you are chemically sensitive or have a high levels of chemical pollution in your environment, it is important to choose an air purifier with enhanced activated carbon.
Photocatalytic oxidation is the combination of UV light and Titanium dioxide. When Titanium dioxide is activated by UV light, it destroys organic pollutants including VOCs, odours, viruses and bacteria.
UV light is a disinfection method that uses short-wavelength ultraviolet (UV-C) light to kill or inactivate microorganisms by destroying nucleic acids and disrupting their DNA, leaving them unable to perform vital cellular functions. UV light is used in a variety of applications, such as food, air, and water purification.
UV light has antibacterial, antiviral, sterilising and deodorising properties against microorganisms.
UV bulbs will deteriorate over time and The Healthy House recommends they are replaced at least every 12 months. Take a look at our Filter (bulb) Replacement Service tab for peace of mind.
How many air purifiers do I need?
Did you know air is lazy? Whereas water will flow to the lowest point to find a level, air will not. So if you have an air purifier in one room the air quality in an adjacent room may not be significantly affected. So portable air purifiers are room specific.
At The Healthy House we recommend the air in the room be changed at least 3 times an hour. This provides a good level of cleaning and will keep up with the normal flow of air into and out of a room. If the room has high traffic or doors and windows are continuously opened and closed you may need a larger unit.
You may find that the size of room a unit is recommended for on our website is different than the size claimed on the box. This will be due to manufacturers using different multiples of ACH. By standardising them you can compare like for like.
We assume that the standard room height is 2.2 metres. So a 10 sq metre room actually has a volume of 22 cubic metres.
There are two main running costs with an air purifier: electricity and replacement filters.
The cost of the electricity will depend on the size and speed of the motor, and over what period of time it is running.
The cost of replacements depends on the amount of pollutants in the air and the cost of a filter.
An air purifier of 45 decibels may seem quiet in a room full of people but could seem audible in a bedroom while you are trying to sleep.
Always check the noise level of specific air purifiers.
A helpful guide from The Health and Safety Executive is: 10 decibels is just audible while around 50 decibels measures a normal conversation.
Both air sterilisers and air purifiers are used for cleaning the air of impurities. However, the technologies used are different.
A simple way to sum up the difference is that air purifiers generally collect unwanted particles in a filter, while air sterilisers actually destroy the particles, including bacteria and viruses.
An air steriliser is convenient and low-maintenance. Due to the sophisticated technologies used in their manufacture, they often come with a slightly higher price tag than filtration-based air purifiers.
We offer air sterilisers from two great brands (Airfree and Radic8) which we’ve carefully selected for their superior technology and effectiveness. Airfrees are maintenance free, having no replaceable parts. The Radic8s use photcatalytic oxidation and contain either a GP or UV bulb, which needs to be replaced once a year.
Air ionisers release negatively-charged molecules into the air to create the sensation of fresh mountain air thanks to electrically-charged molecules called negative ions. These negatively-charged ions ‘wrap’ themselves around positive ions that are responsible for stale and polluted air, drawing them back into the ioniser. Ionisers are effective on their own or as an ionisation unit within an air purifier. An ioniser helps remove dust, pollen, cigarette smoke and pet dander.
Ionisationis the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons to form ions. An air ioniser is a device that uses voltage to ionise air molecules.
Airborne particles are positively charged and are attracted to the negative ions in a similar way that static from your television attracts dust. The negative ions attach to these particles and form larger particles that can be trapped more easily by an air purifier filter or are attracted to surfaces within the room itself.
The ionisation process also has a disinfecting property on viruses and bacteria.
If you are unsure as to which air purifier or air steriliser to choose for your situation, give us a call on 01453 752216 and one of our friendly and knowledgeable staff will be happy to guide you to the right choice.