Sharp makes an excellent line of air filters. Parts, however, do need to be replaced fare more often than officially recommended. Parts can be found at the website, here. Below is a translation of part listings based on the KC500Y model, many of which are usable with other models.

Parts (KC500Y)

sharp-kc500y5

Part Part (in Japanese) Model Number List Price Comments
HEPA Filter 集じんフィルター（HEPAフィルター） FZ-BX50HF 4,400円 Change every 10 years
Charcoal Odor Filter 脱臭フィルター FZ-B50DF 4,000円 Change every 10 years
Pre-Filter 使い捨てプレフィルター（6枚入り） FZ-PF70K1 800円 Change every month
Pet Odor Filter ペット用脱臭フィルター FZ-DF50K1 2,000円 Change every 2 years
Kitchen Odor Filter キッチン用脱臭フィルター FZ-KF50K1 2,000円 Change every 2 years
Silver Ion Water Tank Cartridge Ag+イオンカートリッジ FZ-AG01K1 900円 Change every year
Water Evaporator Filter 加湿フィルター FZ-Y80MF 2,600円 Change every 10 years
Water Tank for White Model タンク 2804210068 2,000円
Water Tank for Black Model タンク 2804210069 2,600円
Water Tank Cap タンクキャップ 2803120012 1,200円
Evaporator Filter Enclosure Backplate フィルターオサエ 2802140115 1,000円
Evaporator Filter Enclosure フィルターワク 2801380018 1,400円
Float フロート 2803380009 1,000円
Evaporator Filter Magnet 磁石 2023730002 600円 Magnet replacement method

Note

Filters tend to get smelly with use. The HEPA and odor filters will need to be replaced every two to three years, depending on use and environment. Dusty or humid locations will need replacement more quickly.

Water evaporator filters are good for less than two years, unless strict cleaning regimens are followed. Cleaning can be done with acids to remove mineral deposits and bleach to kill fungus, but it may be easier to simply replace these filters with third-party filters that are of lower quality but similar performance.

Parts can be found on Amazon or other retailers for far less than list price, especially if buying from a third-party supplier.