Dreo smart humidifiers
Dreo 747S vs HM735S vs HM717S: tank size or warm mist?
Three Dreo towers can look like a simple tank-size ladder, but that misses the choice that matters most: the 747S and HM735S are documented as cool-mist-only models, while the HM717S adds warm mist in a smaller reservoir. Start with the mist type you will actually use, then check the exact height, controls and care instructions for the room where the appliance will live.
Choose warm or cool mist before comparing capacity
The 747S is an 11-liter top-fill ultrasonic cool-mist model. Dreo lists an area claim up to 700 square feet, up to 100 hours, and 21 dB; none of those headline figures is an independent room or sound measurement. The HM735S is also an 11-liter cool-mist tower. If cool mist is the plan, compare the two by height, exact controls, current SKU and documentation rather than assuming that the matching tank volume makes them the same appliance.
The HM717S is the meaningful contrast when warm mist is a requirement: Dreo documents both warm and cool operation, with an 8-liter reservoir. That smaller capacity does not make it worse; it is a different configuration for a household that values a heated-mist option enough to accept more frequent refills than an 11-liter tank may require. If you do not need heated mist, do not pay for complexity you will not use. If you do need it, neither cool-only tower is a substitute.
Measure the footprint, including height
Dreo's 747S dimension graphic lists 31.73 inches high and a 9.65-inch width and depth. The HM735S page lists it at 30.91 inches high. That difference is small on paper but worth checking if the unit must sit beneath a shelf, beside a bed or close to a cabinet. The maker manual for the 747S also asks for a level surface and 12 inches of clearance from walls or major obstacles; mist should be directed away from furniture and electrical equipment. A tall tower is not an easy fit simply because its base is narrow.
The HM717S is a shorter, different design; use its own listed dimensions and exact manual rather than borrowing the 747S clearance or assuming that a shared brand means shared assembly. The same rule applies to the HM735S: check the body height and outlet space for the location you have, not only tank capacity.
Compare controls as a whole plan
The 747S U.S. page lists app, remote, touch and voice control, three mist levels, a 12-hour timer and an Auto response that stops misting at the room target. It does not state which setpoints a U.S. buyer can select. A Dreo-branded manual copy for DR-HHM017S gives a 30–90% target range, but the U.S. product record omits a model number and a separate Dreo U.S. guide says DR-HHM017AS. Keep that selectable range and the manual’s account requirement for voice setup unconfirmed for the exact U.S. SKU. HM735S has its own exact manual and smart-control details; HM717S is another connected model, but do not assume the display, target increments or app behavior are interchangeable.
For a simple on-device routine, ask whether the physical panel or handset can perform your everyday tasks without a phone. For scheduled use, check which functions the app actually handles, and whether account setup is acceptable. “Smart” is not one uniform control package.
Budget time for water care
All three are large wet-path appliances, not maintenance-free reservoirs. A Dreo-branded 747S manual copy describes cleaning the tank and base chamber, rinsing a removable cartridge and drying parts, with weekly aroma-tray cleaning and monthly descaling. Its code-to-U.S.-SKU link remains open, so use the exact U.S. booklet if details differ. HM735S has its own exact multi-part care instructions, including cartridge care. Before choosing between two 11-liter models, compare how much disassembly, rinsing and drying you are willing to do. HM717S likewise has its own warm-water path and safety steps; do not transfer another model’s directions.
The 747S page confirms an aroma-pad tray, but the pad-only oil instruction comes from the manual copy whose U.S. SKU bridge is unresolved. Follow the supplied booklet before adding oil; never infer an approved tank route from a scent feature. Use the exact instructions for the selected model and water conditions; ultrasonic mist can leave mineral residue, and “clean tank” wording does not replace routine cleaning.
Which review should you read next?
Choose the Dreo 747S review if you have room for a 31.73-inch cool-mist tower and want app plus handset control. Compare it with the HM735S review if you want an 11-liter cool-mist alternative with a slightly shorter listed body. Read the HM717S review if warm mist is essential. Dreo's area, runtime and noise numbers remain manufacturer claims; none of these comparisons establishes a guaranteed humidity result in your room.
Exact-model sources: Dreo 747S, Dreo HM735S, and Dreo HM717S. A 747S manual copy identifies model DR-HHM017S, while a separate Dreo U.S. setup guide uses DR-HHM017AS; the suffix link to the current U.S. SKU remains open. Do not treat similar series names as proof of common instructions.