Dreo HM735S 11L Smart Cool Mist Humidifier: features, specs and who it suits

The Dreo HM735S is a large cool mist humidifier with an 11-litre (2.9-gallon) tank. It is aimed at bedrooms and living rooms, with app and voice control, a quiet sleep mode and a top-fill design. This page explains what its main specs mean.

Tank size and runtime

Dreo says the tank gives up to 100 hours of runtime, about four days. A humidifier's runtime depends on the output setting, so the longest figure usually applies to the lowest setting. A large tank means fewer refills, which is handy in a bedroom. A top-fill design lets you pour water in from above without lifting and flipping the tank.

Room coverage and mist

Dreo says it covers rooms up to 700 sq ft (about 65 square metres) and sends mist more than 6 feet high, using a 3,900 RPM motor. The mist is described as 5 μm ultrafine, produced by 2.4 MHz ultrasonic atomization. Ultrasonic models vibrate a plate at high frequency to create a cool mist with no heating element. Dreo says the fine mist avoids white dust on floors. Mineral dust from hard water is a common issue with ultrasonic humidifiers, which is why the demineralization cartridge below is relevant.

Demineralization cartridge

The unit takes a replaceable Dreo demineralization cartridge. Dreo says it uses ion-removal material to reduce free calcium and magnesium in the water, and recommends replacing it monthly. Check how many cartridges are included and where to buy more.

Smart controls

The Dreo app, voice control and the remote let you set schedules, target humidity and cleaning reminders. An auto mode adjusts output to a humidity level you choose. A 12-hour timer is included. Check which assistants and app features your region supports.

Sleep mode and lighting

In sleep mode Dreo rates the noise at 26dB, which is about the level of a quiet room. There is also an RGB night light, which can be dimmed or turned off in the controls. An aroma pad tray adds fragrance if you want it. Use only the products and methods the manual allows.

Cleaning and tank

The tank has an Ag+ coating, which Dreo says keeps the mist cleaner. A humidifier needs regular rinsing and descaling to stay in good condition, and the reminders help. Follow the manual for cleaning agents.

Size

It measures about 10.2 x 8.9 x 30.9 inches (26 x 23 x 78 cm), weighs 5.9 lb (about 2.7 kg) empty and has a 360° adjustable mist outlet. It is tall, so check the space where it will stand.

What to check before you buy

• Room size: compare the 700 sq ft coverage figure with your room.
• Water type: hard water leaves more mineral residue, so plan on cartridges and cleaning.
• Placement: put it on a stable, water-safe surface away from walls and electronics, as the manual suggests.
• Noise: 26dB applies to sleep mode, and higher settings will be louder.
• Upkeep: note the monthly cartridge change and weekly cleaning routine.
• App and Wi-Fi: confirm your network and phone work with the Dreo app.

The short version

• 11-litre top-fill cool mist humidifier with up to 100 hours of runtime, per Dreo.
• Rated for rooms up to 700 sq ft, with 5 μm ultrafine mist.
• App, voice and remote control, auto mode and a 12-hour timer.
• 26dB sleep mode, RGB light, aroma tray and replaceable demineralization cartridge.

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