In order to choose an energy efficient air cleaner that is also cost effective, you really need to understand how any particular model works. Independent air purifier reviews are one way of figuring this out but you also need to consider air purifier ratings to ensure that the unit is capable of doing the job that you want it to.

If you have severe allergies and noise is an issue, then your best bet is to use an air purifier that uses a HEPA filter, such as the Blueair air cleaners. Noise levels from the Blueair register at just 32 dBa, which is comparable to a soft whisper when on low. When on high, this air purifier still only registers at 64 dBa, which is about as loud as a refrigerator.