Honeywell HCM-710 Easy to Care vs Honeywell HUL535 Filter-Free Cool Mist
In short: The Honeywell HUL535 Filter-Free Cool Mist costs $20 less; the Honeywell HUL535 Filter-Free Cool Mist genuinely holds a larger room (246 sq ft against 165 sq ft); the Honeywell HCM-710 Easy to Care cannot produce white dust on hard water and the other can; they are different mechanisms entirely — evaporative against ultrasonic; the Honeywell HUL535 Filter-Free Cool Mist costs about $28 less a year in wicks and watts.
| Spec | Honeywell HCM-710 Easy to Care | Honeywell HUL535 Filter-Free Cool Mist |
|---|---|---|
| Approx. price | ~$75 | ~$55 |
| Type | Evaporative | Ultrasonic |
| Mist | cool | cool |
| Rated output | 0.67 gal/day | 1 gal/day |
| Output standard | Computed from the tank and the maker's longest runtime claim — the lowest setting | Computed from the tank and the maker's longest runtime claim — the lowest setting |
| Honest room size | 165 sq ft | 246 sq ft |
| Claimed coverage | 360 sq ft | 300 sq ft |
| Claim vs physics | 2.18× | 1.22× |
| Tank size | 1 gal | 1 gal |
| Runtime at the claimed room | 16 hr | 20 hr |
| Real runtime at full output | — | — |
| Yearly running cost | ~$39 | ~$11 |
| Replaceable media | Wick, replaced through the season | None — nothing to buy |
| White dust risk | No | Yes |
| Humidistat | No | No |
| Noise on low | — | — |
| Top fill | Yes | No |
| Dishwasher-safe tank | Yes | No |
| App control | No | No |
| Power | 30 W | 38 W |
Highlighted cells are the better number in that row, and only where a direction is unambiguous — more output and more supported room, less noise, cost and price. Honest room size and runtime are computed from each maker’s own published figures; here is the calculation.
Pros and cons
Honeywell HCM-710 Easy to Care
- The easiest unit here to actually clean - top fill plus dishwasher-safe parts means the weekly job takes a minute
- Evaporative and tap-water tolerant, so no dust and no distilled-water habit
- Shares the widely stocked HAC-504 wick with the HCM-350, so filters are never hard to find
- No humidistat, so it runs flat out until the tank empties
- One gallon is a small tank for a 360 sq ft claim - roughly 16 hours if it were actually holding that room
- No UV treatment, unlike the HCM-350 it otherwise resembles
- Wick cost is the same as the bigger model with less output to show for it
Honeywell HUL535 Filter-Free Cool Mist
- No consumables at all - the only ongoing cost is electricity
- Runs a full 24 hours on a tank at a mist level that roughly matches its claimed room size, which is rare here
- Simple enough that there is very little to go wrong
- White dust on hard water, with no demineralisation option built in
- No humidistat, so it cannot stop itself over-humidifying a closed room
- Bottom-fill tank, so every refill is a trip to the sink carrying it upside down
- The ultrasonic disc scales in hard water and needs descaling to keep output up, which the manual covers but the box does not