Quiet but pricey
PRO: Low setting is really quiet. I use medium setting for white noise at night. Works great.  You're supposed to replace filters every 12 months.<br /><br />CON: I have two cats and have to replace every 6 months.  Replacement filters are not easy to find.  You can only buy them online https://www.envionproducts.com/air-purifiers/allergy-pro/ap450/<br /><br /> Replacement filters cost $40 apiece + $10 shipping. Delivery in 4 to 8 weeks. Not very convenient or affordable.
Rating: 3 stars