Humidifiers / Honeywell HWM845B Filter Free Warm Mist Humidifier vs Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)
Honeywell HWM845B Filter Free Warm Mist Humidifier
$54.95
VSHoneywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)
$89.95
Honeywell HWM845B Filter Free Warm Mist Humidifier vs Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)
Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)
A fifteen-year-old evaporative workhorse with UV — and no humidistat at all.
Wins overall by 0.4 points
Quick Verdict
The Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) is the stronger all-round pick, ahead by 0.4 points. A fifteen-year-old evaporative workhorse with UV — and no humidistat at all.
The Honeywell HWM845B Filter Free Warm Mist Humidifier and Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) are both closely matched humidifier models, and the Honeywell HWM845B Filter Free Warm Mist Humidifier is $35 cheaper than the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) ($54.95 vs $89.95). On Safety Around Children, the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) leads (9.5 vs 3.5/10) — burn and scald risk from boiled or heated water, tipping hazard, and whether the hygiene story holds up in a nursery. On Running Cost, the Honeywell HWM845B Filter Free Warm Mist Humidifier leads (8.0 vs 5.0/10) — wicks, demineralisation cartridges, antimicrobial additives, distilled water and electricity — everything you keep paying after the purchase. On Quietness, the Honeywell HWM845B Filter Free Warm Mist Humidifier leads (9.0 vs 6.0/10) — noise at the setting people actually run it overnight, weighted toward independently measured figures over manufacturer claims. Overall, the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) scores 6.8/10 across our 8 scoring categories versus 6.4/10 for the Honeywell HWM845B Filter Free Warm Mist Humidifier. Below, we break down the full spec sheet, category-by-category scores, and exactly who should buy which one.
Side-by-Side Comparison
| Spec | Honeywell HWM845B Filter Free Warm Mist Humidifier | Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) |
|---|---|---|
| Price | $54.95 | $89.95 |
| Release Year | 2018 | 2009 |
| Humidification Technology | Warm mist — Honeywell's manual: "The tank feeds water into the boiling chamber where it is heated to a steam vapor". A resistive element does the boiling; there is no fan and no wick | Evaporative wick with a UV chamber in the water tray — a fan pulls air through the wet HAC-504AW filter |
| White Dust & Mineral Aerosol | None. Boiling leaves minerals behind as scale in the chamber rather than aerosolising them, which is the whole reason warm-mist and steam units are dust-free — and also why the chamber needs descaling | None. The mineral load stays in the wick, which is why Honeywell's manual explains that brown or rust-coloured "mineral deposit" staining on the filter is normal and does not affect performance. Tap water is fine |
| Tank Capacity | 1 gal / 3.7 L | 1.1 gal / 4.2 L |
| Rated Output per Day | Not published by the manufacturer — neither Honeywell's manual nor its store page gives a gallons-per-day or mL/hr figure for the HWM845 | "2 US gallons (7.6 liters) output per day" per Honeywell's own manual — which is nearly twice the tank. Meeting the rated output means filling the 1.1 gal tank roughly twice a day, not once |
| Quoted Runtime (and at which setting) | "Up to 24 hours" — Honeywell's store page attaches this to the LOW of two comfort settings. On high, a 1-gallon tank boiled away goes very much faster | "Up to 24 hours" — on the LOW of three settings. That is 1.1 gal in 24 h, which is barely half the rated 2 gal/day output; the two headline numbers describe two different settings |
| Rated Room Coverage | Sources conflict: Walmart's listing for the HWM845B says 400 ft², office-supply listings for the identical SKU say 520 ft², and Honeywell's own store page says only "medium" room | Sources conflict: Honeywell's own product page says only "medium room" with no square footage, while FiltersFast's listing for the same model states 500-800 ft² |
| Humidistat | None. Two fixed comfort settings on a knob, no humidity sensor, no auto mode. There is an auto shut-off for an empty tank, which is a safety cut-out and not humidity control | None. Three fixed output speeds on a mechanical dial, no humidity sensor, no auto mode and no auto shut-off when the tank runs dry — you are the humidistat |
| Noise | Not published as a decibel figure. There is no fan, so the only noise is the boil itself — genuinely among the quietest ways to humidify a bedroom, at the cost of the heat | Not published as a decibel figure by Honeywell; the product page says only "quiet operation". It is a 60W fan drawing air through a wet wick, so the top speed is clearly audible |
| Filters & Cartridges (Annual Cost) | Nothing is required — it is filter-free. Honeywell offers the optional Protec PC2V1 antimicrobial cleaning cartridge on a 30-day cycle (roughly $20-30/yr if you use it), but the unit runs without it | Two separate consumables. The HAC-504 "Filter A" wick is $32.95 for a Honeywell 3-pack (a compatible FiltersFast 3-pack is $22.99) and Honeywell says replace it every 30-60 days. On top of that the Protec antimicrobial cartridge is a 30-day item. A full heating season is realistically $40-70 |
| Cleaning Burden & Dishwasher-Safe Parts | Honeywell's manual says "Weekly cleaning is recommended" and prescribes two cups of distilled white vinegar in the reservoir for 20 minutes to strip scale, plus a separate bleach disinfection. The tank opening is wide; nothing is dishwasher-safe. Skip the descaling and the element fouls and output collapses | Among the best here. The tank and tray go on the dishwasher's top rack, the tank opening takes a hand, and the manual's disinfection routine is one teaspoon of bleach per gallon. Honeywell says only that it "requires regular cleaning" without naming an interval; the EPA says every third day |
| UV / Antimicrobial Claim | Boiling is the kill stage — no UV lamp and no antimicrobial wick. The optional Protec cartridge is a tank-side cleaning aid, not a certified disinfection claim | Two claims, both qualified. The UV chamber is rated "Up to 99.9% Germ Free*", where the asterisk in Honeywell's own manual ties it to independent testing of microbial reduction after two hours of UV exposure — a water-tray claim, not an air claim. The wick itself is separately treated as a Protec antimicrobial filter |
| Mist Temperature & Burn Risk | Boiled. Honeywell's manual is explicit: "DO NOT touch the steam vapor. Steam can cause burns" and the unit "produces hot steam". The output is genuinely sterile; the trade-off is a reservoir of near-boiling water in the room | Cool, invisible vapour at room temperature — no burn risk at all, which is why this is the standard nursery recommendation |
| Warranty | 36 months | 36 months |
| Colors | Black | White, Black |
Category Scores
Freedom From White Dust
The Honeywell HWM845B Filter Free Warm Mist Humidifier leads clearly here, 10.0 against 9.5 — a 0.5-point margin on the thing marketing never mentions. Ultrasonic humidifiers aerosolise whatever is dissolved in the water and deposit it as white dust on furniture — the EPA notes they are 'very efficient at dispersing minerals in tap water into the air', along with microorganisms from the tank. Evaporative and boiled-steam units do not do this at all. A high score means the technology cannot produce dust; a low score means you are buying distilled water for the life of the machine.. If that is what you are buying for, the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) does not close the gap elsewhere.
Output
The Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) leads clearly here, 7.5 against 6.5 — a 1.0-point margin on actual moisture put into the room per day in gallons or mL/hr, judged against the coverage the manufacturer claims — not the square-footage number on the box. If that is what you are buying for, the Honeywell HWM845B Filter Free Warm Mist Humidifier does not close the gap elsewhere.
Runtime & Refill Interval
The Honeywell HWM845B Filter Free Warm Mist Humidifier leads clearly here, 6.0 against 5.5 — a 0.5-point margin on how long a full tank really lasts at a useful output setting, rather than at the lowest setting the runtime is quoted for, and how painful the refill is. If that is what you are buying for, the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) does not close the gap elsewhere.
Cleaning & Access
The Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) leads clearly here, 8.5 against 6.0 — a 2.5-point margin on whether the tank opening takes an adult hand, whether any part is dishwasher-safe or boilable, and how realistic the manufacturer's stated cleaning interval is to actually keep to. If that is what you are buying for, the Honeywell HWM845B Filter Free Warm Mist Humidifier does not close the gap elsewhere.
Running Cost
The Honeywell HWM845B Filter Free Warm Mist Humidifier leads clearly here, 8.0 against 5.0 — a 3.0-point margin on wicks, demineralisation cartridges, antimicrobial additives, distilled water and electricity — everything you keep paying after the purchase. If that is what you are buying for, the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) does not close the gap elsewhere.
Quietness
The Honeywell HWM845B Filter Free Warm Mist Humidifier leads clearly here, 9.0 against 6.0 — a 3.0-point margin on noise at the setting people actually run it overnight, weighted toward independently measured figures over manufacturer claims. If that is what you are buying for, the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) does not close the gap elsewhere.
Humidity Control
The Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) leads clearly here, 3.0 against 2.5 — a 0.5-point margin on whether there is a genuine closed-loop humidistat holding a setpoint, or just fixed output steps and a timer with a humidity label on it. If that is what you are buying for, the Honeywell HWM845B Filter Free Warm Mist Humidifier does not close the gap elsewhere.
Safety Around Children
The Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) leads clearly here, 9.5 against 3.5 — a 6.0-point margin on burn and scald risk from boiled or heated water, tipping hazard, and whether the hygiene story holds up in a nursery. If that is what you are buying for, the Honeywell HWM845B Filter Free Warm Mist Humidifier does not close the gap elsewhere.
Best For
Choose the Honeywell HWM845B Filter Free Warm Mist Humidifier if…
- • Running Cost matters most to you — the Honeywell HWM845B Filter Free Warm Mist Humidifier scores 8.0/10 here (wicks, demineralisation cartridges, antimicrobial additives, distilled water and electricity — everything you keep paying after the purchase).
- • Quietness matters most to you — the Honeywell HWM845B Filter Free Warm Mist Humidifier scores 9.0/10 here (noise at the setting people actually run it overnight, weighted toward independently measured figures over manufacturer claims).
- • You want to spend less — it's $35 cheaper.
- • Your main use case is warm-mist.
Choose the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) if…
- • Safety Around Children matters most to you — the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) scores 9.5/10 here (burn and scald risk from boiled or heated water, tipping hazard, and whether the hygiene story holds up in a nursery).
- • Cleaning & Access matters most to you — the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) scores 8.5/10 here (whether the tank opening takes an adult hand, whether any part is dishwasher-safe or boilable, and how realistic the manufacturer's stated cleaning interval is to actually keep to).
- • Output matters most to you — the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) scores 7.5/10 here (actual moisture put into the room per day in gallons or mL/hr, judged against the coverage the manufacturer claims — not the square-footage number on the box).
- • Your main use case is nursery.
Pros & Cons
Honeywell HWM845B Filter Free Warm Mist Humidifier
Pros
- +The vapour is genuinely sterilised by boiling — no white dust and no aerosolised tank bacteria, unlike any ultrasonic here
- +No fan means no fan noise; for a light sleeper this is quieter than any wick or ultrasonic unit in this set
- +Truly filter-free — there is no consumable you are required to buy, which over three years undercuts the evaporative units badly
- +Three-year Honeywell warranty at $54.95, and a wide tank opening you can get a hand into
Cons
- −It boils water in a child's bedroom; Honeywell's own manual warns the steam "can cause burns" and to keep it away from children
- −No humidistat whatsoever — two knob positions and nothing that senses the room
- −Weekly vinegar descaling is not optional: mineral scale on the heating element is what kills these units, and Honeywell's manual prescribes the routine
- −Retail listings disagree on coverage — 400 ft² at Walmart versus 520 ft² on office-supply listings for the same SKU — and Honeywell publishes no number at all
- −No published output figure, so the only throughput data point is a 1-gallon tank over 24 hours on low
Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)
Pros
- +Evaporative plus UV: no white dust, no distilled water, and a genuine (if narrowly worded) kill stage on the water
- +Tank and tray are top-rack dishwasher safe, which almost nothing else in this category can say
- +2 gal/day rated output is real humidification, not a desktop trickle
- +Three-year warranty and a filter supply chain that has existed for fifteen years — parts are trivially available
Cons
- −No humidistat, no auto mode and no auto shut-off — it runs until you stop it, and the FiltersFast listing states the omission outright
- −The 2 gal/day output and the 24-hour runtime cannot both be true at once: the 1.1 gal tank means hitting rated output requires two fills a day
- −Two stacked consumables — a $23-33 three-pack of wicks every 30-60 days plus a 30-day Protec cartridge
- −Honeywell publishes no square footage and no decibel rating; retailers fill the gap with a 500-800 ft² figure Honeywell does not make
- −Honeywell's own store now marks the HCM350 discontinued and points buyers at the HEV320W, even though the model is still stocked and supported elsewhere
Shop by Need
FAQs
Is the Honeywell HWM845B Filter Free Warm Mist Humidifier or Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) better overall?+
Based on our 8-category scoring, the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) comes out ahead overall. See the full breakdown in the scores section above — the right pick still depends on which categories matter most for your use case.
Which is better for Safety Around Children, the Honeywell HWM845B Filter Free Warm Mist Humidifier or the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)?+
The Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) scores higher on Safety Around Children (9.5/10 vs 3.5/10) — burn and scald risk from boiled or heated water, tipping hazard, and whether the hygiene story holds up in a nursery.
Which is better for Running Cost, the Honeywell HWM845B Filter Free Warm Mist Humidifier or the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)?+
The Honeywell HWM845B Filter Free Warm Mist Humidifier scores higher on Running Cost (8.0/10 vs 5.0/10) — wicks, demineralisation cartridges, antimicrobial additives, distilled water and electricity — everything you keep paying after the purchase.
Which is better for Quietness, the Honeywell HWM845B Filter Free Warm Mist Humidifier or the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)?+
The Honeywell HWM845B Filter Free Warm Mist Humidifier scores higher on Quietness (9.0/10 vs 6.0/10) — noise at the setting people actually run it overnight, weighted toward independently measured figures over manufacturer claims.
Which is better for Cleaning & Access, the Honeywell HWM845B Filter Free Warm Mist Humidifier or the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)?+
The Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) scores higher on Cleaning & Access (8.5/10 vs 6.0/10) — whether the tank opening takes an adult hand, whether any part is dishwasher-safe or boilable, and how realistic the manufacturer's stated cleaning interval is to actually keep to.
Is the Honeywell HWM845B Filter Free Warm Mist Humidifier worth the price difference over the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)?+
The Honeywell HWM845B Filter Free Warm Mist Humidifier is the cheaper option at $54.95 versus $89.95. Whether the pricier model is "worth it" depends on how much you value its lead in Safety Around Children.
Which is better suited to my use case?+
The Honeywell HWM845B Filter Free Warm Mist Humidifier is the better fit if you mainly care about warm-mist. The Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) is the better fit for nursery.
What's the warranty on the Honeywell HWM845B Filter Free Warm Mist Humidifier vs the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)?+
The Honeywell HWM845B Filter Free Warm Mist Humidifier ships with a 36-month warranty; the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) ships with a 36-month warranty. Always confirm current terms on the manufacturer's site before buying.
Should I wait for the next model instead of buying either of these?+
If either model is more than two years old, a successor may be close — check the "Latest Model" link on each product page. Otherwise, both are current, well-supported options and there's no strong reason to wait.
Cheaper Option
Pure Enrichment MistAire Ultrasonic Cool Mist Humidifier (PEHUMIDIF) — $39.99
Premium Option
Canopy Bedside Humidifier 2.0 — $159.00
Specifications and prices for both products last verified . Scores are calculated from published specifications — see how we compare products.