The function of an air purifier is to pass the air through its filter, trapping the dust and particulate matter while releasing clean air. The filter material and the cleansing channels may vary from device to device. But the functional basics remain the same. Alongside the filter, there are many other important parameters to look for in an air purifier. These are detailed below.
Pre-filter. Without a pre-filter, the main filter of the air purifier will wear out much quickly. This decreases the effectiveness of the main filter over time. Moreover, pre-filter acts as an extra protection against contaminated air. Particulate matters in the scale of PM 2.5 and PM 10 are at large in India. Air purifiers with pre-filters thus become quite important.
HEPA filter. It is the most popular and efficient type of filter for air purifiers. It is used to cleanse out the smallest of particles down to a size of 0.3 micron. Some purifiers come with an ultrafine particle filter with HEPA filters to cleanse particles smaller than 0.3 micron as well.
Activated carbon. Even if you take out the particulates and dusts, what about the odour? Activated carbon is a solution to that. These particles remove gaseous and chemical elements from the air, rendering it odour-free. Some purifiers contain activated carbon as mesh-like sheets, while others contain it as pellets.
Clean-air delivery rate (CADR). It indicates the volume of clean air produced by the purifier every minute. Air purifiers come with CADR ratings for smoke, dust and pollens each. The smoke and dust CADR readings have a maximum capping of 400 CADR, while pollen CADR is 450. Go for a device that offers higher CADR value within the said range. Optimally, an air purifier should have CADR rating of at least 300.
Air change per hour and fan speed. Air change per hour (ACH) indicates the frequency of air purification by the device within its stipulated area in an hour. Air purifiers offering an ACH of 4 and above are preferable. Fan speed determines how loud an air purifier will be. Higher speed may mean louder noise. So prefer an air purifier that has high ACH and CADR but can also be run on low or medium fan speed.
Other points to consider. Before you purchase, ensure that the air purifier has a sufficient coverage for your room/premises. Next, ensure that it is easy and economical to operate and maintain. Ask the vendor about the recommended cleaning and replacement intervals for filters and parts. Avoid ionisers and UV-light-based devices since these release ozone, which is bad for our lungs. Finally, ensure that the air purifier is AHAM or GB/T 18801 standard certified.
Go for an air-purifier from a known brand to ensure reliability and accountability. Different vendors offer different deals on warranties, servicing options and maintenance. Given below are some of the best products in the market.
Philips AC4372. This is one of the best offerings from Philips’ air purifier inventory for larger rooms. It comes with a HEPA filter, an AC filter and a multicare filter. It produces CADR of 341cu.m/hour, maintaining the actual noise level at 38dB. It also comes with child-safety lock. The product is priced at INR 49,000.
Honeywell Touch S8. It comes with a HEPA filter, a pre-filter and an additional HiSiv filter for extra cleaning of organic compounds and odours. It offers a coverage of up to 42sq.m (450sq.ft). The best thing about this air purifier is that it is Wi-Fi-ready and can be controlled through a mobile application. It costs INR 34,000.
Sharp FU-A80E-W. This air purifier, costing INR 27,500, is recommended for coverage up to 30sq.m (about 323sq.ft). It consists of a HEPA filter, which is said to be capable of 99.97 per cent filtration of 2.5PM contaminants. The purifier also comes with a pre-filter and an impressive 480 cu.m/hour CADR. It uses Plasmacluster Ion technology to remove odour without creating any ozone.
Mi Air Purifier 2. Mi’s Air Purifier 2 is a good deal, given its low cost. Priced at INR 9000, it is said to be effective within an area of 21-37sq.m (300sq.ft). It can deliver CADR of 210cu.m/hour. The filtration capacity is strong with a 360-degree primary polyethylene terephthalate (PET) filter, in addition to an ultra-dense EPA filter and an activated carbon filter. It can be controlled over Wi-Fi using a smartphone.
There are many more offerings from these as well as other popular brands like Blue Air, Camfil, Kent and Eureka Forbes. Explore all the available options to select the best device for yourself. Just keep in mind the features we discussed above!