Quick Answer

For most bedrooms, the 306S offers the best balance of size and smart features. Choose the 713S if you need a larger tank and longer runtime for big rooms, and the 612S only if you find it through offline channels—it's identical to the 512S in specs.

Tank Size and Runtime: Match Your Room and Refill Frequency

The biggest difference among these three models is how long they can run before you need to refill. The 306S has a 3L tank that lasts up to 30 hours in sleep mode—great for a bedroom where you might forget to refill nightly. The 713S jumps to 6L and claims up to 60 hours of runtime, which means you can go several days without topping up, especially in a large living area.

The 612S, with its 5L tank, sits in between. But because its specs are identical to the 512S, you can expect similar runtime to that model—though we don't have the exact hours here. If you often run the humidifier all day in a busy room, a larger tank cuts down on interruptions.

Smart Features and Control: What You Actually Get

All three are 'Smart' models, meaning they support app and voice control. But the 713S goes further with a built-in humidity sensor and a tri-color indicator light that shows you the current humidity level at a glance. That's handy if you want to know when to adjust settings without opening an app.

The 306S offers adjustable lighting and an aroma tray for essential oils, which the others don't mention. If you like a spa-like atmosphere in your bedroom, that's a unique perk. The 612S, being the offline twin of the 512S, has a manual mist control knob—so it might not offer the same app-level precision as the 306S or 713S. Check the manual before you buy if app control is a must.

How to Choose: The Trade-Offs

  • Room Size: For rooms up to 300 sq ft, the 306S covers it well. For larger open-plan areas, the 713S with its 6L tank and sensor is more suitable. The 612S is a middle ground but without a stated coverage area. Measure your room and match it to the 306S's 300 sq ft coverage or choose the 713S for bigger spaces.
  • Refill Frequency: If you hate refilling daily, the 713S's 60-hour runtime is a clear win. The 306S lasts 30 hours in sleep mode, which is still enough for a week of nights. The 612S sits in between, but exact runtime isn't specified here. Consider how often you're willing to refill; a larger tank means less maintenance.
  • Smart vs Manual Control: The 306S and 713S support app and voice control, ideal for tech-savvy users. The 612S, being identical to the 512S, may rely on a manual knob—check before buying if you want app scheduling or remote adjustments. If app control is essential, avoid the 612S unless you confirm it has it.
  • Extra Features: The 306S has an aroma tray for essential oils and adjustable lighting, perfect for a spa-like bedroom. The 713S adds warm mist and a humidity sensor with a tri-color light, useful for precise humidity management. The 612S offers no such extras. Think about which extra feature you value more: aromatherapy or humidity sensing.

Key Specs at a Glance

  • Smart Humidifier 306S 3L: 3L tank, up to 30 hours of continuous mist in sleep mode, covers 300 sq ft with 360° mist at 250ml/hr, whisper-quiet at 28dB, aroma tray for essential oils. This is the go-to for a bedroom or small office where you want quiet operation, a compact size, and the option to add a calming scent.

    Smart Humidifier 306S 3L

    Smart Humidifier 306S 3L

  • Smart Humidifier 612S 5L: 5L tank, specs identical to the HM512S, adjustable mist output knob, whisper-quiet ultrasonic technology. If you can find it offline, you get a mid-size tank with manual control—great for those who prefer a simple knob over app settings, but verify availability and exact features.

    Smart Humidifier 612S 5L

    Smart Humidifier 612S 5L

  • Smart Humidifier 713S 6L: 6L top-fill tank, cool and warm mist, built-in humidity sensor with tri-color indicator light, up to 60 hours runtime, app and voice control. This is the powerhouse for large rooms or whole-home use, with a sensor that helps maintain consistent humidity and a long runtime that means fewer refills.

Which One Fits You?

Best For

  • 306S: Bedrooms, nurseries, or small offices up to 300 sq ft where quiet operation and aromatherapy are nice to have.
  • 713S: Large living rooms, open-plan areas, or anyone who wants a long runtime and a built-in humidity sensor.
  • 612S: Those who prefer a simple manual knob and can find it through offline retail channels.

Not For

  • 306S: Not ideal for large rooms over 300 sq ft or if you want warm mist.
  • 713S: Overkill for a small bedroom if you don't need the extra tank size or sensor.
  • 612S: Not for buyers who want app control or a top-fill design (since it's identical to the 512S, check the 512S specs for those details).