Once a want and not a need, air purifiers are now essential electrical appliances at home for people facing indoor air quality issues. The advancement of technology in the air treatment industry has led to a boom in air purifier brands and models with various specifications worldwide allowing consumers to tackle particular indoor air quality problems they are facing. There are various criteria for an air purifier model. Consider all the criteria and narrow down your choices to get the air purifier that suits your needs.
Your indoor air quality needs
The first step in choosing a suitable air purifier is to identify the specific indoor air quality objective you want to achieve. As each type of air filter is designed to tackle different types of air pollutants, having the right air filters in the air purifier is crucial in ensuring that your objective is met. These are some of the common indoor air quality issues that can be solved with the respective air filters:
Asthma and allergies caused by allergens: HEPA filters, ionisers
High-efficiency particulate air filters, or HEPA filters, are air filters that remove at least 99.97% of microscopic particles as small as 0.3μm from the air. They mechanically remove airborne allergens, such as dust particles, pet dander, and mould spores. This type of air filter efficiently prevents allergen-induced asthma and allergies.
Built-in ionisers in air purifiers improve the performance of HEPA filters by generating negative ions that clump airborne allergens together for easy removal.
Transmission of airborne germs: HEPA filters with antibacterial/antiviral layers, UV-C lights
Normal HEPA filters remove bacteria and viruses bigger than the fine mesh on the filters. Even then, the bacteria and viruses are still viable and can be reintroduced into the air. However, HEPA filters with antibacterial/antiviral layers tested in laboratories significantly reduce this concern.
In addition to antibacterial/antiviral filters, UV-C lights in air purifiers destroy bacteria and viruses trapped in the filters. Thus, reducing the risk of reintroducing the germs when air purifiers are opened.
Odours: Activated carbon filters, TiO2 filters
Odours indoors are often caused by volatile organic compounds (VOCs) coming from cigarette smoke, newly painted walls, and pets. As odours are in gaseous form rather than solid, they can pass through HEPA filters easily. The activated carbon filters trap these chemical compounds via adsorption while the TiO2 (titanium dioxide) filters break the compounds down through photocatalysis.
The room size
While you can reference the recommended room sizes provided by air purifier manufacturers, the calculation of the recommended room sizes can be inaccurate as it can be done based on different formulas and does not take into account the room ceiling height.
The clean air delivery rate (CADR) is a reliable specification to check if you want to eliminate the bias in recommended room size calculation. The CADR reading is the volume of air that the air purifiers filter out in an hour. It is affected by the fan speed and how compact the air filters inside the air purifiers are.
A lower CADR means that the air purifier might take a longer time to purify the air in the room but it has better performance due to a compact filter. On the other hand, an air purifier with a higher CADR purifies the air of the room in a shorter period of time. However, it can be noisier due to the powerful fan.
Hence, CADR should be used to compare the efficiency of air filtration in different air purifier brands as it is a standardised metric used by all air purifier manufacturers, not as the guideline to determine if the air purifier has a better performance in cleaning the air.
After narrowing down the air purifier choices based on the filter types and CADR, there are other considerations to take into account for convenience and comfort:
If the air purifier will be used at night, having the sleep mode feature with low fan speed is ideal.
Aside from looking at dimensions and weight, air purifiers with wheels and handles are great if you plan to move them around the house.
Indoor air quality indicator
Besides displaying the real-time indoor air pollutant levels, air purifiers with indoor air quality indicators often have the auto mode feature where they increase the fan speed when a surge of indoor air pollutants is detected and lower the fan speed to save power when the indoor air is clean.
The main function of the pre-filter is to prevent large airborne debris, such as clumps of dust and pet fur, from clogging up the delicate HEPA filter in the air purifier. So having a pre-filter can potentially extend the filter lifespan.
The child-lock feature is a requirement to prevent accidental changes of settings. It’s especially true for households with children and pets.
Controlling the air purifiers through your mobile phones allows you to monitor the indoor quality of your home remotely.
Warranty and after-sales support
Although most air purifier manufacturers provide at least 1 year of warranty, it is important to purchase the air purifier from a local manufacturer for easy access to after-sales support. Some manufacturers also provide extended warranty as a guarantee to make sure that your air purifiers work well for years to come.
Narrowing down your options helps you make a wise decision on the air purifier for your home. Regardless of the brand and the model of the air purifiers you choose, those with good quality filters require a regular filter change for 6 to 12 months intervals. It ensures that your indoor air quality is maintained in the long run.
Disclaimer: The information provided in this article is for general reference only. Please seek advice from professionals according to your needs.