DREO 747S Review: An 11L Smart Humidifier Rated at 21 dB
DREO's 747S is an 11L smart humidifier rated at 21 dB, with up to 100 hours of runtime, coverage up to 700 ft² and app, voice and remote control.
By Daniel Brooks
Updated October 31, 2026
The DREO 747S 11L Smart Humidifier is an 11L smart cool mist humidifier rated at 21 dB, with up to 100 hours of runtime and coverage up to 700 ft². For more models, see our Humidifiers page.
Our Verdict
The 747S solves the usual problem with large humidifiers: noise. At 21 dB it is quiet enough for a bedroom while holding enough water for four days of use.
It is cool mist only and heavy when full. If you want warm mist, DREO’s HM717S is the better fit.
DREO 747S 11L Smart Humidifier
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Key Specifications
| Feature | Specification |
|---|---|
| Brand | DREO |
| Model | 747S |
| Tank | 11L |
| Coverage | Up to 700 ft² |
| Runtime | Up to 100 hours |
| Noise | 21 dB |
| Sensor | 5 percent accuracy, auto mode |
| Controls | App, voice, remote, 12 hour timer |
| Extras | RGB light, aroma tray, anti-scale filter |
Design
The 11L tank fills from the top, and DREO’s Clean Tank design and an anti-scale filter help with upkeep.
A 6 foot mist column and a 180 degree rotating nozzle spread moisture through a large bedroom, living room or office.
Controls
A built-in sensor with 5 percent accuracy drives auto mode, and color indicators show humidity at a glance. Sleep mode dims the lights and lowers noise.
You can use the app, voice commands or the remote, set a 12 hour timer and choose from more than 1500 RGB light colors.
Placement Tips
Set the humidifier on a flat, water-safe surface at least a couple of feet off the floor if you can, and aim the mist into open air rather than at walls, wood furniture, curtains or electronics. Keep it a few feet from the bed or crib so moisture spreads through the room before it reaches you.
Check the room with a hygrometer for the first few days. Most homes feel best between 40 and 60 percent relative humidity, and if windows start to fog or the room smells musty, turn the output down or let the auto mode hold a lower target.
Running Costs and Care
Running costs are low: a humidifier uses far less electricity than a space heater or air conditioner, and the main extras are water, any filters or wicks, and cleaning supplies. Warm mist models use more power than cool mist or evaporative units because they heat the water.
Empty and dry the tank when you can, and clean it at least once a week so bacteria and mold do not build up. Distilled or filtered water reduces white dust from ultrasonic units and slows scale in every type. Before storing it for summer, clean and dry every part.
How It Compares
Against the Levoit OasisMist 1000S, the DREO holds slightly more water and is rated quieter, while the Levoit adds a Plant Mode.
Against the DREO 755S, the 747S is smaller and quieter, while the 755S has a 16L tank and covers a larger room.
Pros and Cons
| Pros | Cons |
|---|---|
| 21 dB rating | Cool mist only |
| 11L tank, up to 100 hours | Heavy when full |
| Auto mode with sensor | Floor-standing size |
| App, voice and remote | RGB lights not for everyone |
| Anti-scale filter and aroma tray | Needs Wi-Fi for app |
Who Should Buy It
| Who Should Buy It? | Who Should Look Elsewhere? |
|---|---|
| Large bedrooms | Warm mist fans |
| Light sleepers | Small nightstands |
| Living rooms | Tight spaces |
| Smart home users | Homes without Wi-Fi |
For more options, see our picks for the best quiet humidifiers and the best DREO humidifiers.
To see how it ranks against similar models, read our best quiet humidifiers, best dreo humidifiers and best humidifiers with remote.
Final Verdict
The DREO 747S 11L Smart Humidifier is a quiet, long-running smart humidifier for large bedrooms and living rooms. You can check the current price and details for the DREO 747S 11L Smart Humidifier.
Frequently Asked Questions
How quiet is the DREO 747S?
DREO rates it at 21 dB.
How big is the tank?
11L, for up to 100 hours of runtime.
How much space does it cover?
Up to 700 ft².
Does it have warm mist?
No, it is cool mist only.
How can I control it?
With the app, voice commands or the included remote.
About the author
Daniel Brooks is a home cooling editor at WikiCooling, covering window, portable, through-the-wall and mini-split air conditioners, fans, and dehumidifiers. He researches cooling capacity, energy efficiency, noise levels, installation requirements, and buyer feedback to help homeowners choose the right unit for their room size, climate, and budget.