Honeywell HPA104 Allergen Plus HEPA Air Purifier review

The Honeywell HPA104 is the compact white console in this Allergen Plus group. Its useful distinction is not an advanced sensor or app: the exact product is a straightforward HEPA machine with direct controls, one replaceable R filter, and a modest published room rating. Honeywell's licensed store marks the HPA104WMP offer discontinued, so this is chiefly a useful reference when identifying an existing unit or checking a specific remaining-stock listing.

Use the 155-square-foot rating as the boundary

Honeywell Plugged In lists the HPA104 for a 155-square-foot room and ties that area to its repeated-cleaning benchmark of about one room-air change every 12.5 minutes, or 4.8 air changes per hour, at the highest setting. The October 2023 AHAM directory gives the exact HPA104WMP smoke CADR as 100 CFM, with dust 106 and pollen 100; the Store page’s related CADR passage names HPA094WMP, so I do not rely on that mislabeled passage for these values. Those pollutant-specific values are not interchangeable; if smoke CADR is your minimum, the HPA104 reaches 100, not 101. A room at the edge of the rating, an open doorway, a high ceiling, a blocked intake, or running at a lower speed changes the practical fit. The figure is a comparison, not a guarantee that every pocket of air passes through the filter.

The unit page calls this a medium-room model, but the finder uses explicit thresholds: 155 square feet meets its 140-square-foot compact tier and stays below the 219-square-foot small tier. A strict 358-square-foot medium-room requirement should not be satisfied by a broad category label. The published basis matters more than the word “medium.”

Direct speed selection, not sensor-led Auto

The shared HPA100-series manual describes three everyday cleaning choices—General Clean, Allergen, and Germ—plus a separate Turbo boost. The model page also lists a filter-change reminder, an automatic shutoff timer with 2-, 4-, and 8-hour settings, and adjustable panel brightness. These are practical ways to choose airflow, switch temporarily to the highest speed, stop a timed run, and dim the controls; they do not turn the HPA104 into an air-quality-monitoring purifier. The manual documents neither particle-sensor Auto nor an app, numeric PM2.5 reading, or color AQI display. The Store's “quiet” wording has no accompanying dB(A) value, so a hard sound limit remains unknown.

A small but recurring filter routine

Honeywell lists one Type R certified HEPA filter and one Type A odor-reducing pre-filter for the HPA104. The R filter is intended to capture particles from air that passes through it; the manufacturer claims up to 99.97% at 0.3 microns and larger. The A pre-filter is described as helping reduce ordinary odors and some VOCs while catching larger debris. It is not a gas detector, a universal chemical filter, or a carbon-monoxide control. Honeywell's guidance is roughly one year for the R and three months for the A, subject to actual dust, smoke, and pet loading. The manual warns that these filters are not washable; check and replace them according to condition, and reset the reminder after servicing. Keeping the required genuine replacement sizes available matters as much as the purchase price of a used unit.

For a recurring filter budget, this is the lightest routine of the three older consoles compared in the HPA family guide: one R cartridge per annual replacement interval rather than the HPA200's two or HPA304's three. That does not make the HPA104 a better fit for a larger room; the 155-square-foot rating is the limiting factor.

Small footprint, but check the label and condition

Honeywell Plugged In gives the body as about 13.5 inches high, 13.9 inches long, and 8.9 inches wide; the Store's HPA104WMP page lists close rounded measurements in length-width-height order. It weighs 7.74 pounds on the licensed Store record. Place it upright on a firm, level indoor surface, leave the intake and outlet clear, and follow the manual's spacing advice. Unwrap the included filters before the first run, turn the unit off and unplug it before opening the grille, and avoid damp locations or a damaged cord.

The two Store pages agree that this HPA104 white configuration is discontinued, even though an old brand product page still has a Buy Now link. Do not read that link as proof of current stock. For an existing HPA104WMP, verify the label, the seller's condition and return terms, and the exact R/A filter fit. For a current purchase, compare the maker's currently listed models by their own repeated-cleaning figures and replacement media; a similar Honeywell name is not proof of equal room performance or compatible filters.

Sources: Honeywell Plugged In HPA104 page, licensed Honeywell Store HPA104WMP listing, HPA104 owner manual, and AHAM 2023 room-air-cleaner directory and HPA090/HPA100/HPA200/HPA300 series manual linked by the exact white listing.