All consumer appliance brands have their own jargon, terminology and description for each of their air purifier products. In that flood of information, they try their best to convince you of the brand’s superiority. It can difficult to understand and compare one product to another. Here is an air purifier guide, with a checklist that will help you with your decision of purchasing.
1. Filters : Pre-Filter, Carbon Filter & HEPA
HEPA or High-efficiency particulate air (HEPA), originally called high-efficiency particulate absorber is the most important part of an air purifier. HEPA filters out the smallest of pollution particles like PM2.5 and PM10 which cause the most damage in the human body as they are not naturally filtered out by the nose. Note, however, a HEPA filter in isolation does not last very long. It should be accompanied by a minimum of a pre-filter so that load of filtering out big particles like dust and dander is not on the HEPA. Choose a purifier that has at least 2 filters to support the HEPA – A pre-filter, a carbon filter and then a HEPA/
2. CADR or Clean Air Delivery Rate
CADR determines the rate at which air is cleaned inside the room. With a high CADR purifier, more air in your room will be cleaner at a point in time. The higher the CADR, the better. As a thumb rule, avoid air purifiers with CADR lower than 100 m3/h.
Many air purifier companies emphasize the benefits of an ionizer, crediting it with ‘mood lifting’ air. However, ionizers come with a byproduct, ozone. Ozone proves to be harmful especially for those with asthma. Some companies will not disclose clearly whether or not they have ozone. Do not settle for lack of information, and email the company if you are unsure of whether or not their product releases ozone. Do not go for an air purifier that does not specifically mention ‘No Ozone’.
To give you an idea, the quietest indoor unit of a split air conditioner will make around 40 dB of noise. Ideally, an air purifier hence should be less than that. Ones less than 40 dB should be fine to use at night when you sleep.
5. Filter Change Indicator
Without an indicator, it is hard to determine when the filter needs a change or cleaning. Choose one that comes with an indicator preferably. It is very important to clean the pre-filter to have a longer life for the HEPA filter.
6. Room Size
Each air purifier can effectively filter out the indoor air based on its capacity. It is important to make sure that the room coverage is as much or more than the size of your room. Like any other appliance, if you use an air purifier in a room larger than it can cover, it will run inefficiently and have a much shorter life.
This is an underrated feature. With a timer, you can set the exact running time of the air purifier especially at night when you are asleep.