Honeywell Allergen Plus HPA120: problems, parts and running costs

Checked: 2026-10-18

Summary

The HPA120 is a compact tabletop HEPA purifier for rooms up to 110 sq ft, and its practical limits matter more than failures: coverage and CADR are low, there are no smart features or air-quality sensor, and it needs a Filter O cartridge every 9-12 months. Running costs are modest — Consumer Reports puts filters at $53 and electricity at $12 a year. At the $59.99 sale price seen at Target and Shipt (2026-10) it is a reasonable small-room pick; above $100 the coverage looks weak next to larger units.

Common problems and fixes

No air-quality sensor or auto mode — the unit has no sensor, app, Wi-Fi, remote, UV or ionization, and no Turbo mode despite some listings; the manual lists three cleaning levels only (Germ, General Clean, Allergen). Fix: pick the speed manually and use the 2/4/8-hour auto-off timer. [8][5]
Filter upkeep on a schedule — the HEPA Filter O is due every 9-12 months and the washable pre-filter needs vacuuming every 2-4 weeks; the filter-check light tells you when, and the reset is a 2-second button hold. Fix: vacuum the pre-filter on schedule to stretch the cartridge. [5][2]
Replacement-filter cost — Consumer Reports lists $53 a year for filters; the cartridge is sold by Honeywell and by third parties, so you are not locked into one supplier. [8][2]

Parts and consumables

True HEPA Filter “O” (HRFO1) — the 3-in-1 cartridge combining a vacuumable pre-filter, activated carbon and HEPA media in one unit; replaced every 9-12 months; Honeywell-branded and third-party versions exist; Consumer Reports puts the annual filter cost at $53. [2][5][8]
Washable pre-filter — the pre-filter portion of the Filter O cartridge; cleaned by vacuuming every 2-4 weeks. [5][2]

Yearly running cost

Electricity and filters only — no subscriptions or other consumables. Consumer Reports puts the annual filter cost at $53 and annual electricity at $12, based on ENERGY STAR’s measured 72 kWh a year for the unit (the unit itself draws 13 W per retailer listings). A typical owner spends about $53 on filters plus about $12 on power per year, with the filter interval set by the 9-12 month replacement schedule. [8][6][12]

When it is a good buy

Store price points: Target and Shipt have shown it on sale at $59.99 from $74.99 (2026-10); Honeywell Store lists the HPA120B and HPA120W at $74.95, marked save $20 (2026-10); Consumer Reports lists $74.99. [12][13][11][15][8]

At or under $75: reasonable for a small bedroom, office or nursery given AHAM Verifide certification, ENERGY STAR, zero ozone and the 5-year limited warranty. [1][2]
Above $100: weak unless the small size or Honeywell brand is specifically needed; the HPA100/200/300 series offer much higher coverage for larger spaces. [6]

The HPA120 is the better pick when a nightstand-sized, certified, 5-year-warranty unit for a small room is the goal. [20][6]